Development and Validation of a Qualitative Method for Target

Dec 22, 2016 - Canadian Food Inspection Agency, Calgary Laboratory, 3650-36th Street N.W., ... Chemical Residues Monitoring Program and Food Safety...
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Development and Validation of a Qualitative Method for Target Screening of 448 Pesticide Residues in Fruits and Vegetables using UHPLC/ESI QOrbitrap based on Data-independent Acquisition and Compound Database Jian Wang, Willis Chow, James S. Chang, and Jon W Wong J. Agric. Food Chem., Just Accepted Manuscript • DOI: 10.1021/acs.jafc.6b05034 • Publication Date (Web): 22 Dec 2016 Downloaded from http://pubs.acs.org on December 25, 2016

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Journal of Agricultural and Food Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

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Journal of Agricultural and Food Chemistry

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Development and Validation of a Qualitative Method for Target Screening of 448

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Pesticide Residues in Fruits and Vegetables using UHPLC/ESI Q-Orbitrap based on

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Data-independent Acquisition and Compound Database

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Jian Wang*†, Willis Chow†1, James Chang‡, and Jon W. Wong§

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* To whom correspondence should be addressed

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[phone: (403) 338-5273; fax: (403) 338-5299; e-mail: [email protected]]

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15

Calgary, Alberta, T2L 2L1, Canada

Canadian Food Inspection Agency, Calgary Laboratory, 3650-36th Street N.W.,

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ThermoFisher Scientific, 355 River Oaks Parkway, San Jose, California, 95134, USA

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§

US Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5100

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Paint Branch Parkway, College Park, Maryland, 20740, USA

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ABSTRACT A semi-automated qualitative method for target screening of 448 pesticide

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residues in fruits and vegetables was developed and validated using ultra-high

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performance liquid chromatography coupled with electrospray ionization quadrupole

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Orbitrap high resolution mass spectrometry (UHPLC/ESI Q-Orbitrap). The Q-Orbitrap

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Full MS/dd-MS2 (data dependent acquisition) was used to acquire product-ion spectra of

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individual pesticides to build a compound database or an MS library, while its Full

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MS/DIA (data independent acquisition) was utilized for sample data acquisition from

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fruit and vegetable matrices fortified with pesticides at 10 and 100 µg/kg for target

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screening purpose. Accurate mass, retention time and response threshold were three key

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parameters in a compound database that were used to detect incurred pesticide residues in

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samples. The concepts and practical aspects of in-spectrum mass correction or solvent

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background lock-mass correction, retention time alignment and response threshold

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adjustment are discussed while building a functional and working compound database for

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target screening. The validated target screening method is capable of screening at least

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94% and 99% of 448 pesticides at 10 and 100 µg/kg, respectively, in fruits and

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vegetables without having to evaluate every compound manually during data processing,

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which significantly reduced the workload in routine practice.

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KEYWORDS: UHPLC/ESI Q-Orbitrap, pesticide residues, compound database, target

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screening, fruits and vegetables

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INTRODUCTION

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There are over 1000 pesticides that could be potentially used to protect crops

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against a wide range of pests and fungi, and provide quality preservation of food and

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agricultural commodities. Pesticide residues, which might pose a potential risk for human

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health due to their sub-acute and chronic toxicity, could remain in crops such as fruits and

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vegetables. It is important to control or regulate the uses of pesticides in crop production

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and to monitor their levels for compliance so as to ensure the safety of the food supply.

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National and international bodies such as Canada,1 United States,2 European Union,3,4 and

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Codex5 have conducted health risk assessment of pesticide residues in food to establish

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maximum residue limits (MRLs) and set regulations for monitoring programs for

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domestic food safety and international trade of foods. In Canada, Health Canada

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determines the allowable/safe amount of pesticide residues in food, and sets science-

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based MRLs to ensure the safety of Canadian food supply.1 Many food commodities such

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as fruits, vegetables, infant food, tea, grains, pulses etc., have been tested for pesticide

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residues under the Canadian National Chemical Residues Monitoring Program and Food

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Safety Action Plan by the Canadian Food Inspection Agency.6

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Both gas- and liquid-chromatography single or triple quadrupole mass

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spectrometry have been widely used to determine pesticide residues in food.7,8 These

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techniques are routinely utilized for target analysis, in which standard calibration curves

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are required for the quantitation and identification of analytes. Recently, LC-Orbitrap and

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LC-Time of Flight (TOF) have been increasingly used for the quantitation and

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identification of pesticide residues in food.9-15 The Orbitrap and TOF mass spectrometers

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offer high mass-resolution (> 20,000 FWHM), accurate mass measurement (< 5 ppm),

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excellent Full MS scan sensitivity, and complete mass spectrometric information. Besides

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quantitation and identification, the high mass-resolution and accurate mass measurement

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capabilities of Orbtrap and TOF allow for the screening of pesticides based on their

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accurate masses. These types of analyses are often referred to as screening methods or

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semi-automated MS-based detections. This screening concept offers laboratories an

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effective means to expand their analytical scope to chemicals such as pesticides, which

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potentially have a low probability of being present in the samples. Pesticides that occur

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more frequently would continue to be monitored using validated quantitative multi-

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residue methods.16 Recent studies have shown that methods by TOF17,18 and Orbitrap11,19

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have been used for pesticides screening based on accurate mass measurements through

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MS library searches or custom database matching.

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This study was designed to develop, for the first time, a systematic and detailed

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protocol for the development of a compound database (CDB) and its applications for

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target screening of 448 pesticides in fruits and vegetables. The CDB was built based on

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theoretical and experimental mass data. Exact mass was calculated using the elemental

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composition of a pesticide. Accurate mass (measured with mass accuracy ≤ 5 ppm),

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retention time and response threshold were three key parameters that were considered

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while building a functional and working CDB. These parameters were used to optimize

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the CDB to reduce false negatives and/or false positives. Full MS/dd-MS2 (data

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dependent acquisition) was utilized to acquire product-ion spectra of pesticides for

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individual standards that were used to build the compound database. Full MS/DIA (data

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independent acquisition) was used to acquire sample data from fruits and vegetable

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matrices fortified with pesticides at 10 and 100 µg/kg. The method was validated

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according to SANTE/11945/2015.16 This qualitative method significantly reduced the

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workload for data processing in routine practice. The entire procedure including sample

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extraction and data processing was quick and simple enough to allow for high-throughput

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testing of routine samples, which could benefit pesticide residue monitoring programs.

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MATERIALS AND METHODS

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Materials and Reagents. Five fruit and five vegetable blank samples were

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obtained from local markets. Fruits included apple, banana, grape, orange and strawberry.

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Vegetables included carrot, potato, tomato, broccoli and lettuce. All samples were

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blended using a food processor at room temperature and 2 kg of each sample was

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prepared and kept in -20 °C. Pierce LTQ ESI positive ion calibration solution (10 mL)

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was purchased from ThermoFisher Scientific (Rockford, IL). The calibration solution,

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which contained n-butylamine (m/z 74), caffeine (m/z 195 and its fragment m/z 138),

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Ultramark 1621 (m/z 1022, 1122, 1222, 1322, 1422, 1522, 1622, 1722, 1822) and MRFA

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(m/z 524), was used to tune and calibrate the Q-Orbitrap. Ammonium acetate (reagent

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grade), formic acid (LC-MS grade, ~98%), ammonium formate (MS grade, >99.0%),

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methanol (LC-MS grade, Chromsolv, 2.5L) and acetonitrile (LC-MS grade, Chromasolv,

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2.5 L) were purchased from Sigma-Aldrich Corp (Oakville, Canada). Enviro Clean Mylar

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Pouches (6.0 g anhydrous magnesium sulfate (MgSO4) and 1.5 g anhydrous sodium

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acetate) and Enviro Clean extraction columns (900 mg MgSO4, 150 mg C18 and 300 mg

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primary secondary amine (PSA), 15 mL centrifuge tubes) were purchased from United

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Chemical Technologies, Inc (Bristol, PA). Acetic acid (glacial acetic acid, reagent grade,

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99.7%), acetonitrile (distilled in glass) and methanol (distilled in glass) were obtained

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from Caledon Laboratories Ltd (Georgetown, Canada). Water (18.2 MΩ⋅Cm) used for

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reagent and sample preparation was obtained from a Barnstead Nanopure system

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(Thermo Scientific). Pesticides standards were obtained from EQ Laboratories Inc

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(Atlanta, GA), Riedel-de Haen AG (Seelze, Germany) or Chem Service (Westchester,

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PA). LC vials were Mini-UniPrep syringeless filter device with polypropylene housing

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and PVDF 0.45 µm membrane (Whatman Inc., Florham Park, NJ ).

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Preparation of Standard Solutions. Individual pesticide standard stock solutions

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were generally prepared at a concentration of 4000.0 µg/mL in methanol/acetonitrile

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(50:50, v/v). Due to their poor solubility, carbendazim was prepared at 200.0 µg/mL and

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some pesticides were prepared at 1000.0 or 2000.0 µg/mL. Intermediate pesticide

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standard mix solutions were prepared at 10.0 µg/mL and 15.0 µg/mL in

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methanol/acetonitrile (50:50, v/v), from stock solutions. Due to the large number of

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pesticides (~450), intermediate solutions were prepared in separate 200 mL (15 µg/mL,

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including ~ 200 stocks) and 250 mL (10 µg/mL, including ~ 250 stocks) volumetric

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flasks. Stock and intermediate solutions were stored at -20 °C. A two-level pesticide

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standard mix working solution was prepared by transferring 1.5 and 15.0 mL of 10.0

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µg/mL or 1.0 and 10.0 mL of 15.0 µg/mL intermediate working solution into two

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separate 100 mL volumetric flasks for their respective concentration levels, and then

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making up to volume with a mixture of methanol and acetonitrile (50:50, v/v). The

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resulting concentrations were 0.15 and 1.50 µg/mL, which were used for sample

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fortification at 10 and 100.0 µg/kg in sample. All working solutions were stored at 4 °C.

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UHPLC/ESI Q-Orbitrap Parameters. UHPLC/ESI Q-Orbitrap system

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consisted of an Accela 1250 LC pump and an Accela open autosampler coupled with a Q

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Exactive mass spectrometer (ThermoFisher Scientific, Germany). The system was

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controlled by Xcalibur 2.4 software.

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Ultra-high Pressure Liquid Chromatography. The UHPLC column utilized was a Hypersil Gold, 100 mm × 2.1 mm, 1.9 µm column (Thermo Scientific, USA) and

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UHPLC guard column was an Accucore aQ 10 × 2.1 mm, 2.6 µm Defender cartridge

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(Thermo Scientific, USA). The mobile phases and the LC gradient profile were identical

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to conditions presented elsewhere.13

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Q-Orbitrap Parameters. The Q-Exactive ion source was equipped with a heated

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electrospray ionization (HESI) probe and the Q-Orbitrap was tuned and calibrated using

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positive LTQ calibration solution once per week.

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To obtain the product-ion spectra that were used to build the in-house compound

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database, the Q-Exactive was operated in Full MS/dd-MS2. During the Full MS scan, the

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Q-Exactive mass-resolution was set at 70,000 FWHM; AGC target: 1.0E6; maximum IT:

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250 ms; and scan range m/z 80 to 1100. If the targeted mass of a compound from the

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inclusion list was detected within ±5 ppm mass tolerance, the precursor ion was isolated

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by the quadrupole and sent to the HCD (higher energy collisional dissociation) cell for

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fragmentation via the C-trap. The inclusion list, which consisted of the masses of

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precursor ions (with a few present as fragments) in forms of [M+H]+, [M+NH4]+ and

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[M+Na]+ for pesticides, is listed in Table 1. The precursor ion was fragmented with a

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stepped normalized collision energy (NCE) to generate product-ion spectra. For dd-MS2,

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the Q-Exactive mass-resolution was set at 35,000 FWHM; AGC target: 2E5; maximum

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IT: 120 ms; isolation window: m/z 1.0; NCE/stepped NCE: 20, 40 and 60; underfill ratio:

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10%; intensity threshold: 1.7E5; apex trigger: 3 to 6 s; and dynamic exclusion: 10.0 s.

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Each pesticide standard was injected twice on the system at 50 µg/L (ppb) or higher

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concentration.

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For target screening of pesticides in samples, data independent acquisition (DIA)

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was performed through Full MS-SIM (m/z 100-1000), DIA-1 (m/z 100-500), and DIA-2

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(m/z 500-900) sequentially (Figure 1). For Full MS-SIM, the Q-Exactive mass-resolution

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was set at 70,000 FWHM; AGC target: 3.0E6; maximum IT: 200 ms; scan range: m/z 100

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to 1000. For DIA-1 with a mass range from m/z 100 to 500, the Q-Exactive was set the

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mass-resolution at 35,000 FWHM; AGC target: 2.0E6; maximum IT: auto; loop count:

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16; MSX count: 1; isolation window: m/z 25.0; and NCE/stepped NCE 20, 40, 60. Thus,

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a collection of ions isolated by the quadruple in every m/z 25 mass increment from m/z

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100 to 500 in 16 steps were sent to HCD cell for fragmentation via the C-trap. For DIA-2

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with a mass range from m/z 500 to 900, the Q-Exactive mass-resolution was set at 35,000

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FWHM; AGC target: 2.0E6; maximum IT: auto; loop count: 4; MSX count: 1; isolation

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window: m/z 100.0; and NCE/stepped NCE: 20, 40, 60. Thus, a collection of ions isolated

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by the quadruple in every m/z 100 mass increment from m/z 500 to 900 in 4 steps were

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sent to HCD cell for fragmentation via the C-trap. The inclusion list for DIA consisted of

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the masses: 112.80116, 137.81253, 162.8239, 187.83527, 212.84663, 237.85800,

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262.86937, 287.88074, 312.89211, 337.90348, 362.91485, 387.92622, 412.93758,

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437.94895, 462.96032, 487.97169, 550.50011, 650.54559, 750.59106 and 850.63654.

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Other Q-Exactive generic parameters were: sheath gas flow rate set at 60; Aux gas flow

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rate: 30; Sweep gas flow rate: 2; Spray voltage (KV): 3.50; Capillary temperature (°C):

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350; S-lens level: 55.0 and Heater temperature (°C): 350 as reported elsewhere.13,14

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Sample Preparation and Extraction Procedure. For fortification experiment,

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fruit and vegetable samples (15.0 g/sample) were weighed into individual 50 mL

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polypropylene centrifuge tubes (VWR International, Canada). One mL per two-level

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sample spike pesticide standard working solution was added into each centrifuge tube to

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provide 10.0 or 100.0 µg/kg of pesticides equivalent in sample. Sample extraction and

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clean-up procedures followed the buffered QuEChERS presented elsewhere.13,14,20. The

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final sample extracts were either diluted 1:1 or concentrated 3:1. For 1:1 dilution, 250 µL

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of each sample extracts and 250 µL of 0.1 M ammonium acetate and methanol (50:50,

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v/v) were transferred into separate Mini-UniPrep vials (Whatman Inc., USA). The vials

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were capped, vortexed for 30 s and pressed to filter the solution. Sample extracts were

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then ready for UHPLC/ESI Q-Orbitrap injections. For 3:1 concentration, 3 mL of sample

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extracts was evaporated to 0.1 − 0.2 mL using an N-EVAP nitrogen evaporator

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(Organomation Associates Inc., USA) at 30 °C under a stream of nitrogen. The extracts

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were made up to 0.5 mL with methanol, vortexed for 30 s, and then made up to 1.0 mL

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with 0.1M ammonium acetate and vortexed again for 30 s. Five hundred microliters of

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each extract was transferred into a Mini-UniPrep vial (Whatman Inc., USA), and the vials

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were capped, vortexed for 30 s, and pressed to filter. Sample extracts were ready for

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UHPLC/ESI Q-Orbitrap injections.

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Data Processing. The Target Screening function of TraceFinder 3.3 was used for

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data processing based on the compound database developed in house. For target

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screening parameter settings, response threshold was set individually for each pesticide

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(Table 1, column 4); mass accuracy: 5 ppm for both precursor ion and fragment; retention

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time window: 60 s; minimum number of fragments: 1; and MS order: MS2.

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Experimental Design and Method Validation. The method was validated at

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10.0 and 100.0 µg/kg for a total of 10 matrices that included 5 fruits (i.e. apple, banana,

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grape, orange and strawberry) and 5 vegetables (i.e. carrot, potato, tomato, broccoli and

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lettuce). For each matrix, samples were spiked at 10.0 or 100.0 µg/kg, in duplicate. After

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sample extraction and clean-up, the final sample extracts were either diluted 1:1 or

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concentrated 3:1 prior to UHPLC/ESI Q-Orbitrap injections. The experiment was

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repeated on three different days. The positive screen of a pesticide should meet the

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criterion that it can be detected in at least 95% of the 20 samples (i.e. an acceptable false-

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negative rate of ≤ 5%) in a batch.16

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RESULTS AND DISCUSSION

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Sample Preparation or QuEChERS. Pesticides were extracted from fruits and

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vegetables following the QuEChERS method. The sample extracts were either diluted 1:1

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or concentrated 3:1. Dilution was intended to simplify the sample preparation procedure

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for a routine practice while the concentration step was meant to increase the final

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concentration of pesticides in vial to improve the method sensitivity for detectability. The

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QuEChERS provided acceptable recoveries for 448 pesticides in fruits and vegetables,

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which were presented elsewhere.13

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Data Acquisition. Full MS/dd-MS2 was used to acquire product ion spectra of

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individual pesticides. The product-ion spectra provided the accurate masses of fragments

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that were used to build a compound database (CDB) and MS library. The retention times

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were taken from the extracted chromatograms of a Full MS scan. The development of the

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CDB was the main focus of the current study. This included exploring its practicality and

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applicability for data processing or semi-automated target screening. The further

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examination and expansion of the MS library was kept for future study or investigation.

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It was determined that Full MS/dd-MS2 was not sufficient for sample data

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acquisition. This may be because the instrument scan speed was not fast enough to trigger

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every dd-MS2 scan, especially when a large number of pesticides in the inclusion list

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were injected on to the system in the same analytical run. Alternatively, Full MS/DIA,

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which acquired fragment ions of all precursors as for per defined mass range, was utilized

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for sample data acquisition. The Q-Orbitrap first performed one Full MS, followed by

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two DIAs sequentially (Figure 1). Therefore, the extracted chromatograms of Full MS

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provided the retention times and DIAs offered the accurate masses of all fragments

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generated in HCD as per defined quadrupole mass isolation window, i.e. m/z 25 for a

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mass range of m/z 100-500 and m/z 100 for m/z 500-900.

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Target Screening Parameters and Criteria. The target screening or semi-

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automated qualitative analysis was performed using TraceFinder 3.3 Target Screening

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function. The screening parameters and criteria were based on either retention time (±

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0.5 min) and mass accuracy (≤ 5 ppm) of a precursor (RTP by Full MS) or retention time

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(±0.5 min) and mass accuracy (≤ 5 ppm) of a precursor and its fragment ion (RTFI by

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Full MS/DIA). A method performance acceptability criterion was set at an acceptable

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false-negative rate of ≤ 5%. Screening results of incurred residues by RTP approach were

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considered as tentative positive findings while those by the RTFI were taken as

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confirmative positive findings.

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Compound Database. The accurate masses, retention times and response

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thresholds are three key parameters in the compound database (CDB). They were first

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organized in a Microsoft Excel template and then imported to Tracefinder 3.3 to create an

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executable compound database (eCDB). The exact masses of precursors were calculated

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theoretically from their elemental compositions while the accurate masses of their

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fragments were obtained from the product-ion spectra of individual standards (50 µg/L)

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acquired using Full MS/dd-MS2. The Q-Orbitrap performed a three-step normalized

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collision, i.e. NCE at 20, 40 and 60, to induce fragmentation. The fragments, which were

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generated sequentially in three NCEs and collected in the HCD, were sent altogether to

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the Orbitrap analyzer via C-Trap for single scan detection. Since the stepped NCE was

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not optimized for each individual pesticide, the obtained product-ion spectra did not

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represent the best quality in terms of sensitivity for identification, especially for low

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abundance fragments. However, the developed CDB served the purpose for target

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screening of pesticides at the required concentration levels as indicated in the validated

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results.

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A pesticide can be ionized in the form of [M+H]+, [M+NH4]+ or [M+Na]+. Often

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its protonated form showed the highest abundance (Table 1, column 5). The four most

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abundant fragments (Table 1, columns 8-11) plus the precursor (Table 1, column 7) were

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selected to build the CDB. The accurate mass of the precursor, which was eventually

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replaced by the exact mass, was always placed in the first column in the Excel template,

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followed by the masses of four fragments arranged according to ion abundance from high

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to low.

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Mass Correction. There is usually a mass measurement error obtained from the

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experimental mass data. Mass correction, which is based on either in-spectrum mass

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correction or solvent background lock-mass correction, was made to achieve the best

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accurate mass for the CDB using the following equations.

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 =  +  × (∆ /1,000,000) ∆ =

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− × 1,000,000 

Where ∆ : mass accuracy or mass error in ppm; A: corrected mass; B: measured mass; C: exact mass or theoretical value.

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When the mass error of a precursor was less than 2.5 ppm, the mass correction

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was made according to the mass accuracy of the precursor in the dd-MS2 product-ion

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spectrum and this is called in-spectrum mass correction. When a precursor was not

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observed in the dd-MS2 product-ion spectrum or its mass error was greater than 2.5 ppm,

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the mass correction was made according to the mass accuracy of an ion in the background

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of a Full MS scan spectrum, i.e. m/z 214.08963, which is n-butyl benzenesulfonamide,

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and this is termed solvent background lock-mass correction. The 2.5 ppm cutoff was

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arbitrarily chosen to reduce the probability of mass over correction. Columns 8-11 in

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Table 1 present the corrected masses for fragments and column 7 lists the exact masses of

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the precursors. The masses in columns 7-11 in Table 1 were used to build a compound

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database for target screening. It should be noted that the eCDB with corrected masses can

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only be used for screening but not for identification since these masses (not theoretical

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values) cannot be used to derive mass accuracy of fragments.

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There were a total of 448 pesticides (Table 1, column 1) or 461 entries (Table 1,

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column 2) in the in-house developed compound database. Some pesticides had multiple

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entries due to their different ionization forms such as [M+H]+, [M+NH4]+ or [M+Na]+,

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resulting in close or equal ion abundance. For a few pesticides, their fragments were used

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as “precursors” for further induced fragmentation (Table 1, column 5) because their

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precursors showed very low ion intensities due to significant in-source fragmentation.

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Retention Time Alignment. The retention times (tR) of individual pesticides, which

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were obtained from their extracted ion chromatograms based on the exact masses, were

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input into the CDB. The tR and its tolerance were found to be critical for the data

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processing software (i.e. TraceFinder 3.3) to identify an incurred pesticide in samples and

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to match its fragments in the eCDB. However, retention times drifted slightly within a

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batch and/or between batches. The current version of the software (TraceFinder 3.3) in

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screening mode cannot update the tR after the data is processed. It was also not practical

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to adjust every single tR for each batch because of the large number of compounds in the

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eCDB. Alternatively, a single stable and well-characterized compound was used to

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calculate a correction constant. The correction constant was applied to all pesticides in

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the CDB for the batch. This correction effectively aligned the retention times to the

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reference and this process was termed as “tR alignment”. For example, the retention time

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of 3-hydroxycarbofuran, ~4.50 min, was chosen as the reference for the tR alignment. If

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the tR of 3-hydroxycarbofuran were 4.50 min in the eCDB while the observed tR were

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4.61 min in a current batch, the time difference would be 0.11 min. The 0.11 min was

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added to the tR to each pesticide in the eCDB. For routine practice, the tR correction and

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alignment were achieved using a Microsoft Excel template. The new set of tR was

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transferred to the CDB (Microsoft Excel) and then imported to TraceFinder 3.3 to

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override the tR in the eCDB.

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Response Threshold Adjustment. Response threshold is a parameter that can be

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assigned a value for each compound in the eCDB. The software will integrate a peak

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when a sample signal response surpasses the threshold. Response threshold can be

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assigned a generic number such as 30,000 or individual values. If a generic default is set

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too low, this could result in an increased number of false positives. For example, if the

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response threshold were set at 30,000, the number of false pesticide positives could range

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from 40 to 69 in 30 blank samples (Figure 2B). The detected peaks could result from a

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trace amount of pesticides present in the “blank samples”, or most likely small adjacent

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peaks or interferences from a noisy baseline that were above the response threshold. If a

321

generic default is set too high, the screening result may end up with an increased number

322

of false negatives. For a screening method to be effective, it is essential to set appropriate

323

response thresholds to reduce false positives and/or false negatives. It has been well

324

known that the ionization efficiency of individual analytes differs in the electrospray ion

325

source, and that matrix effects could cause ion suppression or enhancement. Therefore,

326

response thresholds should be set accordingly for each pesticide.

327

To set appropriate response thresholds for individual pesticides, a mixture of

328

standards, which was prepared at 5 µg/L in solvent, was injected 20 times on to the

329

UHPL/ESI Q-Orbitrap and data were acquired by Full MS/DIA. The 5 µg/L in solvent

330

was equivalent to 10 µg/kg in sample when the final sample extracts were diluted 1:1.

331

After data acquisition and processing, the peak areas of individual pesticides were

332

averaged. The averaged original peak areas (OPA) at 5 µg/L were not adopted directly as

333

response thresholds because the values were high and could lead to a large number of

334

false negatives. Potential matrix effects, mainly ion suppression, and day-to-day

335

instrument sensitivity variation were also taken into account. The values of 5, 10 or 15%

336

OPA were tested for their applicability to determine the appropriate response thresholds

337

to be used in routine practice. When response thresholds were set at 5, 10 or 15% OPA,

338

the number of false negatives was not that different from that at 30,000 default (Figure

339

2A). Some pesticides (6 to 11 pesticides, Figure 2A) were not detected actually due to

340

their poor signal responses. However, while screening 30 blank samples (10 matrices in

341

triplicate) using response thresholds set at 5, 10 or 15% OPA, the number of false

342

positives was significantly reduced, compared to that of 30,000 default (Figure 2B). For

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343

example, the false positives were in a range of 12-30, 9-23 or 9-19 with response

344

thresholds at 5, 10 or 15 % OPA, respectively, compared to a range of 40-69 at 30,000

345

default (Figure 2B). In the current study, 10% OPA was used as the response threshold

346

values for data processing.

Page 16 of 39

347

It should be noted that tR alignment should be performed for every batch of

348

analysis but mass correction and response threshold should be corrected or set once at the

349

beginning when building the eCDB. Response threshold can be adjusted accordingly

350

based on routine experiences to help reduce false positives in the presence of a high

351

constant matrix background.

352

Validation and Results. The target screening method was validated using

353

SANTE/11945/201516. Ten blank sample matrices (5 fruits and 5 vegetables) were spiked

354

at 10 µg/kg and 100 µg/kg in duplicate, respectively, and the experiment was repeated on

355

three different days. For every pesticide, there were a total of 20 samples per batch that

356

were used to validate the method and meet the criterion that a pesticide had to be detected

357

in at least 95% of the samples (i.e. an acceptable false-negative rate of ≤ 5%).

358

After data acquisition, the results from samples spiked at 10 µg/kg were first

359

processed by the RTP approach using a default of response threshold of 30,000. The data

360

were then manually checked by going through 55,320 (461×20×2×3) individual

361

chromatograms from 461 entries in 20 samples per batch, in which sample extracts were

362

either diluted 1:1 or concentrated 3:1, and repeated on a total of three different days. This

363

was to assess whether the screening parameter settings (i.e. mainly response threshold

364

and tR tolerance) were properly set and to confirm that the eCDB was working properly.

365

Since the nearest tR algorithm was used for the peak detection, the software could

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366

possibly integrate an adjacent peak, a noisy baseline or a shoulder peak as the peak of

367

interest, and presented them as positives. Therefore, any false positives as a result of peak

368

misidentification were counted as failed or not being detected during the manual check.

369

In the initial evaluation, any pesticide which failed once to meet the acceptable

370

false-negative rate of ≤ 5% on any of the three days’ experiments, whether sample

371

extracts were diluted 1:1 or concentrated 3:1, was counted as “not being detected”.

372

Therefore, 396 entries out of 461 were screened as positives in the spiked samples with

373

1:1 dilution (Figure 3A) and 402 with 3:1 concentration (Figure 3B) by manual check.

374

When response thresholds were set at 10% OPA, the numbers of entries detected were

375

closer to the results from the manual check than those from 30,000 default (Figure 3A

376

and 3B). The number of false positives were reduced when appropriate response

377

thresholds were used.

378

It was assumed that a tighter criterion for tR tolerance would reduce the number of

379

false positives. When ± 0.2 min was applied, up to 19 pesticides (Figure 3A and 3B) fell

380

outside the tR range, compared to the manually checked results. In this case, a narrower tR

381

window actually increased the number of false negatives. Therefore, the tolerance of ±0.2

382

min was too stringent while ±0.5 min was considered practical because it resulted in less

383

false negatives.

384

Figure 4 presents the final validated results based on the criteria of mass accuracy

385

±5 ppm and tR ±0.5 min by either RTP or RTFI using 10% OPA as response thresholds.

386

Taking Day 1 as an example (samples spiked at 10 µg/kg with 1:1 dilution), 402 entries

387

were detected by RTP and 340 by RTFI (Figure 4A). The method proved to be

388

reproducible as indicated by the repeatability of the results from 3 different days at the

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389

concentration levels of 10 and 100 µg/kg, whether the sample extracts were diluted 1:1 (5

390

µg/L in vial) or concentrated 3:1 (30 µg/L in vial). In general, there were more pesticides

391

detected for both tentative and confirmative screening at 100 µg/kg than at 10 µg/kg as a

392

result of higher peak intensities at a higher concentration (Figure 4).

393

Since the method was developed for the purpose of target screening, the final

394

validated results were consolidated to represent the optimal detection scenario of

395

minimizing false negatives. For example, when a pesticide was detected in at least 95%

396

of the samples on one of the 3-day experiments, it was included in the method. In

397

addition, the isobaric compounds were added to the list since they were possibly

398

mislabeled as false negatives due to the same mass but slightly different retention times.

399

The results in Figure 4 (the last 2 columns) represent the optimal detection scenario for

400

the method. In other words, the final method was able to tentatively screen 419 pesticides

401

(94% of 448 pesticides) (1:1 dilution) or 423 (94%) (3:1 concentration) and to

402

confirmatively screen 370 (83%) (1:1 dilution) or 385 (86%) (3:1 concentration) at 10

403

µg/kg (Figure 4A, last 2 columns); and to tentatively screen 444 pesticides (99% of 448

404

pesticides) (1:1 dilution) or 443 (99%) (3:1 concentration) and to confirmatively screen

405

408 (91%) (1:1 dilution) or 413 (92%) (3:1 concentration) at 100 µg/kg (Figure 4B, last 2

406

columns).

407

It was observed that there was not much difference in the detectability of

408

pesticides by RTP for tentative screening, whether sample extracts were diluted 1:1 or

409

concentrated 3:1 for the concentration levels of 10 µg/kg and 100 µg/kg (Figure 4 A and

410

B). When fragment ions were included for confirmative screening, for example RTFI at

411

10 µg/kg (Figure 4A), there were significant differences in detectability of pesticides

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412

between the diluted and concentrated sample extracts. There were more fragments ions

413

detected in the concentrated sample extracts (30 µg/L in vial) than diluted (5 µg/L in vial)

414

at 10 µg/kg (Figure 4A). Once again, this resulted from higher peak intensities at a higher

415

concentration.

416

Blind Spike Experiment. The method was further evaluated by a blind spike

417

experiment. The 10 blank sample matrices (5 fruits and 5 vegetables) were spiked with 2

418

to 8 pesticides per sample in a range of from 10 to 500 µg/kg by one analyst, with a total

419

of 41 pesticides spiked in this experiment (Table 2). The spiked samples were analyzed

420

by a second analyst who was not informed of which pesticides were spiked into the

421

samples. All 41 pesticides were successfully identified in the spiked samples (Table 2,

422

indicated as “Yes”) by both RTP and RTFI with the exception of carbaryl, which

423

fragment ion did not match that in eCDB (Table 2, indicated as “No”). Note that all of the

424

sample extracts were diluted 1:1 in the blind spike experiment.

425

In conclusion, UHPLC/ESI Q-Orbitrap along with a compound database can be

426

used for target screening. When building a compound database, the data for individual

427

pesticides were acquired using Full MS/dd-MS2. The in-house developed compound

428

database contained the retention times and the exact or accurate masses of 448 pesticides

429

(including precursors and their fragments). Accurate mass, retention time and response

430

threshold were three key parameters considered when optimizing the compound database.

431

Mass correction, retention time alignment and response threshold adjustment were made

432

to the compound database to reduce false negatives and/or false positives. When

433

screening pesticides in samples, the data were acquired using Full MS/DIA. The

434

screening parameters and criteria were based on either retention time (±0.5 min) and

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435

mass accuracy (≤ 5 ppm) of a precursor (RTP by Full MS) or retention time (±0.5 min)

436

and mass accuracy (≤ 5 ppm) of a precursor and its fragment ion (RTFI by Full MS/DIA).

437

The screening method performance acceptability criterion was set at an acceptable false-

438

negative rate of ≤ 5%. Based on the criteria and parameter settings used in this study, the

439

RTP approach tentatively found 94% and 99% of the 448 pesticides while the RTFI

440

confirmatively screened ≥ 83% and ≥ 91% in fruits and vegetables at 10 and 100 µg/kg,

441

respectively. In general, this semi-automated qualitative method screens not only

442

pesticides but also includes other chemical residues and contaminants in food in future

443

applications. For forthcoming studies, the exact masses of all fragments need to be

444

determined for simultaneously screening and identifying pesticides in food matrices.

445

ACKNOWLEDGEMENTS

446

Authors are grateful to Daniel Leung and Wendy Cheung, Calgary Laboratory,

447

Canadian Food Inspection Agency, for purchasing and preparation of pesticide standards

448

for the study; and to Wendy Cheung for preparing blind spike samples.

449

SUPPORTING INFORMATION

450 451

Detailed validation results and a list of pesticides for target screening in the final method.

452

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453

REFERENCES

454

1.

455

sc.gc.ca/cps-spc/pest/part/protect-proteger/food-nourriture/mrl-lmr-eng.php.(accessed:

456

10 October 2016).

457

2.

458

https://www.epa.gov/pesticide-tolerances. (accessed: 10 October 2016).

459

3.

460

23 February 2005 on maximum residue levels of pesticides in or on food and feed of

461

plant and animal origin and amending Council Directive 91/414/EEC. Off. J. Eur. Union

462

2005, L 70, 1-16.

463

4.

464

consumption and animal feedingstuffs

465

http://ec.europa.eu/sanco_pesticides/public/index.cfm?event=homepage&CFID=1404859

466

&CFTOKEN=69040180&jsessionid=2405714dcd661a78e106TR#. (accessed: 10

467

October 2016).

468

5.

469

limits. http://www.fao.org/fao-who-codexalimentarius/standards/pesticide-mrls/en/

470

(accessed: 10 October 2016).

471

6.

472

(accessed: 8 August 2016).

473

7.

474

priority pesticides: better by GC-MS or LC-MS/MS? Mass Spectrom. Rev. 2006, 25, 838-

475

865.

Health Canada, Maximum residue limits for pesticides. http://www.hc-

US Environmental Portection Agency, Maximum residue limits for pesticides. .

Regulation (EC) No 396/2005 of the European Parliament and of the Council of

Eropean Union, Maximum pesticide levels for food products for human

Codex Alimentarius, Pesticide residues in food and feed. Maximum residue

CFIA, Canadian Food Inspection Agency. http://www.inspection.gc.ca/.

Alder, L.; Greulich, K.; Kempe, G.; Vieth, B., Residue analysis of 500 high

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476

8.

Soriano, J. M.; Jimenez , B.; Font, G.; Molto, J. C., Analysis of carbamate

477

pesticides and their metabolites in water by solid phase extraction and liquid

478

chromatography: a review. Crit. Rev. Anal. Chem. 2001, 31, 19-52.

479

9.

480

pesticide residues in paprika using ultra-high performance liquid chromatography

481

coupled to high resolution Orbitrap mass spectrometry. Food Control 2016, 60, 683-689.

482

10.

483

methodology to determine pesticides and mycotoxins in green tea and royal jelly

484

supplements by liquid chromatography coupled to Orbitrap high resolution mass

485

spectrometry. Food Chem. 2016, 197, 907-915.

486

11.

487

and qualitative screening of pesticides in fruits and vegetables using LC-Q-Orbitrap™-

488

MS. Food Addit. Contam. Part A. 2015, 32, 1628-1636.

489

12.

490

Liquid chromatography Orbitrap mass spectrometry with simultaneous full scan and

491

tandem MS/MS for highly selective pesticide residue analysis. Anal. Bioanal. Chem.

492

2015, 407, 6317-6326.

493

13.

494

chromatography electrospray ionization Q-Orbitrap mass spectrometry for the analysis of

495

451 pesticide residues in fruits and vegetables: method development and validation. J.

496

Agric. Food Chem. 2014, 62, 10375-10391.

497

14.

498

liquid chromatography and electrospray ionization quadrupole orbitrap high-resolution

Reinholds, I.; Pugajeva, I.; Bartkevics, V., A reliable screening of mycotoxins and

Martínez-Domínguez, G.; Romero-González, R.; Garrido Frenich, A., Multi-class

Zomer, P.; Mol, H. G. J., Simultaneous quantitative determination, identification

Del Mar Gómez-Ramos, M.; Rajski, Ł.; Heinzen, H.; Fernández-Alba, A. R.,

Wang, J.; Chow, W.; Chang, J.; Wong, J. W., Ultrahigh-performance liquid

Wang, J.; Chow, W.; Leung, D.; Chang, J., Application of ultrahigh-performance

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499

mass spectrometry for determination of 166 pesticides in fruits and vegetables. J. Agric.

500

Food Chem. 2012, 60, 12088-12104.

501

15.

502

Gilbert-López, B.; Martos, N. R.; Molina-Díaz, A., Determination of over 350 multiclass

503

pesticides in Jams by ultra-high performance liquid chromatography time-of-flight mass

504

spectrometry (UHPLC-TOFMS). Food Anal. Method. 2015, 9, 1939-1957.

505

16.

506

validation procedures for pesticides residues analysis in food and feed.

507

SANTE/11945/2015 Supersedes SANCO/12571/2013 Implemented by 01/01/2016.

508

http://ec.europa.eu/food/plant/docs/pesticides_mrl_guidelines_wrkdoc_11945.pdf.

Pérez-Ortega, P.; Lara-Ortega, F. J.; García-Reyes, J. F.; Beneito-Cambra, M.;

European Union, Guidance document on analytical quality control and method

(accessed: 10 October 2016).

509 510

17.

Mezcua, M.; Malato, O.; Garcia-Reyes, J. F.; Molina-Diaz, A.; Fernandez-Alba,

511

A. R., Accurate-mass databases for comprehensive screening of pesticide residues in food

512

by fast liquid chromatography time-of-flight mass spectrometry. Anal. Chem. 2009, 81,

513

913-929.

514

18.

515

Evaluation and validation of an accurate mass screening method for the analysis of

516

pesticides in fruits and vegetables using liquid chromatography-quadrupole-time of

517

flight-mass spectrometry with automated detection. J. Chromatogr. 2014, 1373, 40-50.

518

19.

519

screening method for pesticides in vegetables and fruits based on liquid chromatography

520

coupled to full scan high resolution (Orbitrap) mass spectrometry. Anal. Bioanal. Chem.

521

2012, 403, 2891-2908.

López, M. G.; Fussell, R. J.; Stead, S. L.; Roberts, D.; McCullagh, M.; Rao, R.,

Mol, H. G. J.; Zomer, P.; De Koning, M., Qualitative aspects and validation of a

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522

20.

523

extraction and partitioning with magnesium sulfate gas chromatography/mass

524

spectrometry and liquid chromatography/tandem mass spectrometry.

525

http://www.eoma.aoac.org/methods/info.asp?ID=48938. First Action, 2007.

Page 24 of 39

AOAC Official Method 2007.01. Pesticide residues in foods by acetonitrile

526

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527

Journal of Agricultural and Food Chemistry

FIGURES

528 529

Figure 1. The Full MS/DIA data acquisition design. Full MS-SIM (m/z 100-1000)

530

followed by DIA-1 (m/z 100-500) and DIA-2 (m/z 500-900) sequentially. DIA: data

531

independent acquisition.

532 533

Figure 2. UHPLC/ESI Q-Orbitrap target screening response threshold adjustment. A: a

534

number of false negatives from 20 pesticide standard injections at 5 µg/L or ppb in

535

solvent. B: a number of false positives from blank samples of 10 matrices (apple,

536

banana, grape, orange, strawberry, carrot, potato, tomato, broccoli and lettuce) prepared

537

in triplicate. Data acquisition: Full MS/DIA. OPA: original peak area.

538 539

Figure 3. UHPLC/ESI Q-Orbitrap target screening results based on response threshold at

540

30,000 default or 10% OPA with tR tolerance ± 0.5 min or ± 0.2 min, and mass accuracy

541

≤ 5 ppm. Samples were spiked at 10 µg/kg. A: sample extracts with 1:1 dilution. B:

542

sample extracts with 3:1 concentration. Results for Day 1-3 were based on 461 entries in

543

the compound database. Data acquisition: Full MS/DIA. OPA: original peak area. RTP:

544

retention time and precursor.

545 546

Figure 4. UHPLC/ESI Q-Orbitrap target screening results based on response threshold at

547

10% OPA with tR tolerance ± 0.5 min and mass accuracy ≤ 5 ppm. A: samples were

548

spiked at 10 µg/kg, sample extracts with 1:1 dilution (5 µg/L in vial) or 3:1 concentration

549

(30 µg/L in vial). B: samples were spiked at 100 µg/kg, sample extracts with 1:1 dilution

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550

(50 µg/L in vial) or 3:1 concentration (300 µg/L in vial). Results for Day 1-3 were based

551

on 461 entries in the compound database. Results for “Final” were based on 448

552

pesticides. Data acquisition: Full MS/DIA. OPA: original peak area. RTP: retention time

553

and precursor. FI: fragments. RTFI: retention time and fragment ion.

554 555

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Journal of Agricultural and Food Chemistry

Table 1. Pesticide compound database c

Mass ID

Compound name

d

a

2

Chemical formula

b

Adduct

4

5

1

3-Hydroxycarbofuran

C12H15NO4

183282

[M+H]

2

Abamectin B1a

C48H72O14

65359

3

Acephate

C4H10NO3PS

4

Acetamiprid

5 6

Retention time (min)

Exact

Accurate

Accurate

Accurate

Accurate

Precursor

Fragment 1

Fragment 2

Fragment 3

Fragment 4

6

7

8

9

10

11

4.50

238.10738

181.08584

163.07528

135.08045

145.06466

[M+Na]+

10.03

895.48143

751.40199

455.23917

327.19297

240.11173

45850

[M+H]+

1.82

184.01918

142.99258

95.04948

141.00018

105.04508

C10H11ClN4

2526382

[M+H]+

4.60

223.07450

126.01056

56.05023

90.03431

Acetochlor

C14H20ClNO2

701931

[M+H]+

8.17

270.12553

224.08347

148.11190

59.04984

133.08848

Acibenzolar-S-methyl

C8H6N2OS2

794492

[M+H]+

7.60

210.99943

91.05476

136.00894

139.97484

167.96976

7

Aclonifen

C12H9ClN2O3

54406

[M+H]+

8.45

265.03745

248.03437

182.05994

218.03646

194.04734

8

Acrinathrin

C26H21F6NO5

145776

[M+Na]

9.86

564.12161

483.09370

405.35829

355.23506

155.77136

9

Akton

C12H14Cl3O3PS

725658

[M+H]+

9.46

374.95396

114.96159

169.96831

204.93722

10 11

Alachlor Aldicarb

C14H20ClNO2 C7H14N2O2S

701931 332444

+

8.19 5.45

270.12553 116.05285

238.09909 89.04228

162.12760 70.06565

147.10422 61.01125

90.01114 88.07602

12

Allethrin

C19H26O3

428341

[M+H] Fragment [M+H]+

9.31

303.19547

303.11994

121.10143

135.08079

93.07069

13

Allidochlor

C8H12ClNO

770378

[M+H]+

5.58

174.06802

98.09684

132.95873

81.07049

56.05023

14

Ametryn

C9H17N5S

6419621

[M+H]

+

7.05

228.12774

186.08086

96.05614

116.02800

71.06106

15

Amicarbazone

C10H19N5O2

184962

[M+Na]+

6.02

264.14310

165.07477

183.08556

16

Aminocarb

C11H16N2O2

1822853

[M+H]+

2.18

209.12845

152.10699

137.08354

122.06036

17

Ancymidol

C15H16N2O2

2066521

[M+H]

+

6.26

257.12845

81.04542

135.04419

177.09111

121.06514

18 19

Anilofos Aramite

C13H19ClNO3PS2 C15H23ClO4S

3267450 420146

[M+H]+ [M+NH4]+

8.51 9.32

368.03053 352.13438

142.99253 211.08642

198.96454 184.09941

170.96965 191.14289

156.95404 183.09164

20

Aspon

C12H28O5P2S2

2994197

[M+H]

9.70

379.09262

114.96158

210.90465

252.95150

294.99838

21

Asulam

C8H10N2O4S

204120

[M+Na]+

2.33

253.02535

220.99929

214.08951

208.98376

22

Atrazine

C8H14ClN5

668278

[M+H]+

6.88

216.10105

174.05410

96.05612

104.00145

23

Azaconazole

C12H11Cl2N3O2

1913306

[M+H]+

7.12

300.03011

158.97625

230.99736

172.95551

24

Azadirachtin

C35H44O16

42241

[M+Na]+

6.60

743.25216

725.23991

665.21641

565.16815

625.18640

25

Azamethiphos

C9H10ClN2O5PS

1897338

[M+H]+

5.93

324.98093

182.99551

127.98985

130.00545

111.99515

26

Azinphos-ethyl

C12H16N3O3PS2

381330

[M+Na]+

8.01

368.02629

132.04436

95.04960

150.05482

105.03384

27

Azinphos-methyl

C10H12N3O3PS2

266730

[M+Na]+

7.24

339.99499

132.04432

95.04957

150.05480

160.05034

28

Azoxystrobin

C22H17N3O5

2152537

[M+H]+

7.40

404.12410

372.09748

329.07912

344.10261

183.05526

29

Barban

C11H9Cl2NO2

187323

[M+H]+

7.79

258.00831

143.07302

178.04185

130.06530

204.02119

30

Benalaxyl

C20H23NO3

3750931

[M+H]+

8.55

326.17507

148.11211

91.05484

121.08892

208.13328

31

Benazolin

C9H6ClNO3S

26874

[M+H]+

5.73

243.98297

169.98227

197.97719

225.97196

134.00572

32

Bendiocarb

C11H13NO4

394657

[M+H]+

6.17

224.09173

109.02879

167.07023

81.03409

59.04988

33

Benfluralin

C13H16F3N3O4

16607

[M+H]+

9.59

336.11657

57.07073

280.05409

262.04358

34

Benfuracarb

C20H30N2O5S

12722

[M+H]+

9.08

411.19482

195.04755

252.06888

162.06755

158.11764

35

Benodanil

C13H10INO

3627992

[M+H]+

6.78

323.98798

230.93033

94.04194

105.03394

120.04472

36

Benoxacor

C11H11Cl2NO2

1327039

[M+H]+

7.31

260.02396

149.08357

120.04466

134.06014

188.07068

37

Bensulide

C14H24NO4PS3

756633

[M+Na]+

8.32

420.04973

240.01241

378.00272

335.95572

317.94523

38

Benzoximate

C18H18ClNO5

57616

[M+H]+

8.72

364.09463

199.01568

105.03396

202.00271

95.04969

39 40

Bifenox Bifenthrin

C14H9Cl2NO5 C23H22ClF3O2

132330 196552

[M+Na]

[M+NH4]+

8.81 10.41

363.97500 440.15987

90.97715 181.10111

92.61828 166.07767

158.96406 165.06982

41

Bispyribac

C19H18N4O8

720553

[M+H]+

7.53

431.11974

275.06584

119.01295

90.97715

261.05030

42

Bitertanol

C20H23N3O2

131079

[M+H]+

8.70

338.18630

70.04068

99.08091

269.15303

251.14311

43

Boscalid

C18H12Cl2N2O

1236803

[M+H]+

7.64

343.03995

307.06287

271.08615

272.09418

139.98968

44

Brodifacoum

C31H23BrO3

866786

[M+H]+

10.03

523.09033

178.07774

335.04281

256.12456

165.06993

45

Bromadiolone

C30H23BrO4

279504

[M+Na]+

9.12

549.06719

531.05683

273.05196

46

Bromuconazole, cis-

C13H12BrCl2N3O

303219

[M+H]+

7.91

375.96136

158.97642

70.04077

47

Bromuconazole, trans-

C13H12BrCl2N3O

5568

[M+H]+

8.42

375.96136

158.97641

70.04067

48

Bupirimate

C13H24N4O3S

4855759

[M+H]+

8.08

317.16419

166.09760

108.01180

210.16018

150.10268

49

Buprofezin

C16H23N3OS

3898907

[M+H]+

9.28

306.16346

201.10580

57.07073

106.06568

116.05328

50 51

Butachlor Butafenacil

C17H26ClNO2 C20H18ClF3N2O6

579783 1078002

[M+H]+ [M+NH4]+

9.34 7.91

312.17248 492.11437

238.09928 179.98446

57.07071 331.00856

162.12771 349.01911

87.08114 123.99479

52

Butralin

C14H21N3O4

644170

[M+H]+

9.67

296.16048

240.09774

222.08724

208.07156

132.08078

53

Butylate

C11H23NOS

626877

[M+H]+

9.15

218.15731

57.07070

156.13838

162.09494

190.16225

54

Cadusafos

C10H23O2PS2

1185447

[M+H]+

8.90

271.09498

130.93854

158.96969

114.96162

215.03230

55

Carbaryl

C12H11NO2

321742

[M+H]+

6.40

202.08626

102.09177

62.06079

145.06483

85.06543

56

Carbendazim

C9H9N3O2

3812432

[M+H]+

3.26

192.07675

160.05055

132.05570

57

Carbetamide

C12H16N2O3

675410

[M+H]+

5.70

237.12337

118.08647

120.04457

72.08146

192.06532

58

Carbofuran

C12H15NO3

3366094

[M+H]+

6.08

222.11247

165.09114

123.04441

91.05486

59

Carbophenothion

C11H16ClO2PS3

112709

[M+H]+

9.58

342.98113

156.98724

114.96172

60

Carboxin

C12H13NO2S

5367001

[M+H]+

6.28

236.07398

143.01623

93.05793

124.02186

208.04278

61

Carfentrazone-ethyl

C15H14Cl2F3N3O3

478864

[M+H]+

8.33

412.04371

345.99564

366.00188

384.01245

276.97431

62

Carpropamid

C15H18Cl3NO

666991

[M+H]+

8.49

334.05267

139.03110

103.05483

196.02935

124.07608

63

Chlorbromuron

C9H10BrClN2O2

19826

[M+Na]+

7.65

314.95064

92.61896

1

3

Response threshold

+

+

+

+

ACS Paragon Plus Environment

132.03241

Journal of Agricultural and Food Chemistry

64

Chlorbufam

C11H10ClNO2

34773

[M+H]

+

7.52

224.04728

206.03675

178.04180

65

Chlordimeform

C10H13ClN2

4000

[M+H]+

3.87

197.08400

117.05759

152.02601

66

Chlorfenvinphos

C12H14Cl3O4P

1663693

[M+H]

+

8.60

358.97681

98.98469

67

Chlorfluazuron

C20H9Cl3F5N3O3

264865

[M+H]

+

9.76

539.97024

382.93641

68

Chloridazon

C10H8ClN3O

3214800

[M+H]+

4.49

222.04287

69

Chlorimuron-ethyl

C15H15ClN4O6S

32874

[M+H]

+

7.65

70

Chlorotoluron

C10H13ClN2O

259393

[M+H]

+

71 72

Chloroxuron Chlorpropham

C15H15ClN2O2 C10H12ClNO2

4718472 239922

73

Chlorpyrifos

C9H11Cl3NO3PS

74

Chlorpyrifos-methyl

75

Page 28 of 39

145.08858

130.06526

169.96847

204.93735

155.04675

158.04137

141.01478

186.95883

104.04994

92.05006

95.04970

128.98516

415.04736

186.00659

184.99049

83.02468

121.02873

6.63

213.07892

72.04513

88.07631

96.05306

7.97 7.77

291.08948 172.01598

72.04133 154.00580

218.03685 126.01104

164.09451 93.05811

139.00614

949309

[M+H]+ Fragment [M+H]+

9.38

349.93356

114.96176

197.92767

171.02402

293.87082

C7H7Cl3NO3PS

321763

[M+H]+

8.86

321.90226

142.99275

289.87610

78.99506

127.01571

Chlorpyrifos-oxon

C9H11Cl3NO4P

2173088

[M+H]+

8.23

333.95640

197.92763

277.89382

305.92508

179.96146

76

Clethodim

C17H26ClNO3S

9033

[M+H]+

8.99

360.13947

164.07099

166.08675

136.07614

206.11830

77

Clodinafop-propargyl

C17H13ClFNO4

2685903

[M+H]

+

8.32

350.05899

266.03782

91.05486

222.01176

238.04291

78

Clofentezine

C14H8Cl2N4

805519

[M+H]+

8.70

303.01988

138.01060

130.04019

156.02107

120.04473

79

Cloquintocet-mexyl

C18H22ClNO3

4454116

[M+H]+

9.26

336.13610

238.02662

192.02116

179.01332

220.01611

80

Clothianidin

C6H8ClN5O2S

469541

[M+H]

+

4.11

250.01600

131.96691

169.05405

113.01705

110.07158

81

Coumaphos

C14H16ClO5PS

1528324

[M+H]+

8.50

363.02174

226.99289

90.97731

306.95914

211.01580

82 83

Coumaphos-oxon Crotoxyphos

C14H16ClO6P C14H19O6P

2874172 300665

[M+H]+ [M+NH4]+

7.18 7.67

347.04458 332.12575

290.98197 127.01558

211.01578 105.07028

319.01324 167.04667

165.01034 302.17288

84

Crufomate

C12H19ClNO3P

4078265

[M+H]+

8.34

292.08638

126.03173

236.02386

57.07071

222.00824

85

Cumyluron

C17H19ClN2O

1769408

[M+H]+

7.90

303.12587

185.04751

125.01537

119.08574

91.05475

86

Cyanazine

C9H13ClN6

1955786

[M+H]

+

5.76

241.09630

214.08558

96.05624

104.00156

132.03260

87

Cyanofenphos

C15H14NO2PS

546704

[M+H]+

8.46

304.05556

159.02067

156.98732

276.02432

136.02169

88

Cyazofamid

C13H13ClN4O2S

472818

[M+H]+

8.16

325.05205

108.01193

217.04039

261.09039

126.02226

89

Cyclanilide

C11H9Cl2NO3

164520

[M+H]+

8.05

274.00323

131.03410

161.98731

113.02379

95.01340

90

Cycloate

C11H21NOS

837674

[M+H]+

8.93

216.14166

83.08615

134.06348

154.12262

72.04510

91

Cyclohexamide

C15H23NO4

283099

[M+Na]+

5.55

304.15193

178.04772

92.62362

90.97728

92

Cycloxydim

C17H27NO3S

2052487

[M+H]+

8.96

326.17844

280.13659

180.10197

101.04250

93

Cycluron

C11H22N2O

3310537

[M+H]+

7.05

199.18049

89.07158

72.04515

69.07066

94

Cyflufenamid

C20H17F5N2O2

2282376

[M+H]+

8.68

413.12830

203.02287

241.03958

295.08657

95

Cyfluthrin

C22H18Cl2FNO3

44680

[M+Na]+

9.70

456.05400

92.61852

96 97

Cymoxanil Cypermethrin

C7H10N4O3 C22H19Cl2NO3

86198 162291

[M+Na]+ [M+NH4]+

4.78 9.79

221.06451 433.10802

90.97716 127.03115

177.04785 91.05493

176.00583 181.06472

98

Cyphenothrin

C24H25NO3

233003

[M+H]+

9.97

376.19072

123.11698

151.11161

81.07046

181.06482

99

Cyproconazole

C15H18ClN3O

1507496

[M+H]+

8.00

292.12112

70.04077

125.01558

100 Cyprodinil

C14H15N3

4989004

[M+H]+

8.15

226.13387

108.08149

93.05811

133.07650

119.06100

101 Cyprosulfamide

C18H18N2O5S

843941

[M+H]+

5.87

375.10092

135.04429

121.02882

254.08125

95.04983

102 Cyromazine

C6H10N6

3044121

[M+H]+

1.32

167.10397

85.05150

125.08240

60.05642

103 Daimuron 104 Deltamethrin

C17H20N2O C22H19Br2NO3

1804169 132177

[M+H]+ [M+NH4]+

7.73 9.77

269.16484 521.00700

151.08692 278.90136

119.08605 225.04289

108.08142 299.06158

91.05501 171.98817

105 Demeton-S

C8H19O3PS2

49919

[M+H]+

7.35

259.05860

89.04251

61.01139

185.02965

215.03980

106 Demeton-S-methylsulphon

C6H15O5PS2

2973432

[M+H]+

3.32

263.01713

127.01571

169.00832

142.99270

121.03210

107 Desmedipham 108 Dialifos

C16H16N2O4 C14H17ClNO4PS2

705488 438761

7.05 8.77

301.11828 208.01598

136.03932 181.00503

182.08119 166.98939

154.04980 130.02884

108.04480 89.03915

109 Di-allate

C10H17Cl2NOS

609210

[M+H]+ Fragment [M+H]+

8.96

270.04807

86.06071

108.96110

128.10719

142.94843

110 Diazinon

C12H21N2O3PS

4592067

[M+H]+

8.49

305.10833

169.07949

114.96175

153.10232

90.97728

111 Dichlofenthion

C10H13Cl2O3PS

190191

[M+H]+

9.36

314.97728

258.91445

203.03142

114.96162

178.94836

112 Dichlormid

C8H11Cl2NO

547881

[M+H]+

6.40

208.02905

81.07054

98.09695

139.96644

95.04970

113 Dichlorvos

C4H7Cl2O4P

1356186

[M+H]+

6.09

220.95318

127.01568

78.99501

90.97725

144.98158

114 Diclobutrazol

C15H19Cl2N3O

60112

[M+H]+

8.29

328.09779

70.04077

158.97637

115 Diclocymet

C15H18Cl2N2O

647701

[M+H]+

8.14

313.08690

172.99208

137.01537

102.04696

85.04032

116 Dicrotophos

C8H16NO5P

1430536

[M+H]+

3.90

238.08389

112.07617

72.04518

127.01576

193.02629

117 Diethofencarb

C14H21NO4

397841

[M+H]+

7.38

268.15433

124.03947

226.10720

152.07050

180.10179

C14H21NO4

246679

[M+Na]+

7.41

290.13628

204.10023

90.97726

118 Difenacoum

C31H24O3

1987999

[M+H]+

9.64

445.17982

179.08561

257.13254

165.07000

359.02832

119 Difenoconazole

C19H17Cl2N3O3

1301207

[M+H]+

8.87

406.07197

251.00260

337.03918

188.03891

233.00783

120 Diflubenzuron

C14H9ClF2N2O2

931442

[M+Na]+

8.25

333.02128

92.61401

196.16092

222.77451

121 Dimepiperate

C15H21NOS

33372

[M+H]+

8.96

264.14166

146.06337

119.08577

91.05479

122 Dimethachlor

C13H18ClNO2

1803604

[M+H]+

7.20

256.10988

224.08370

148.11207

132.08095

123 Dimethametryn

C11H21N5S

12585161

[M+H]+

8.12

256.15904

186.08091

91.03306

96.05620

71.06112

124 Dimethenamid

C12H18ClNO2S

2481007

[M+H]+

7.62

276.08195

244.05573

168.08417

234.18524

111.02674

125 Dimethoate

C5H12NO3PS2

965616

[M+H]+

4.46

230.00690

142.99264

198.96467

88.02216

170.96969

126 Dimethomorph

C21H22ClNO4

805982

[M+H]+

7.56

388.13101

301.06259

165.05478

138.99460

273.06775

127 Dimethylvinphos

C10H10Cl3O4P

1366635

[M+H]+

7.94

330.94551

127.01596

169.96880

204.93781

301.17027

128 Dimetilan

C10H16N4O3

2550278

[M+H]+

4.79

241.12952

72.04511

196.07175

129 Dimoxystrobin

C19H22N2O3

1694879

[M+H]+

8.36

327.17032

134.06025

116.04991

58.02960

205.09736

130 Diniconazole

C15H17Cl2N3O

992057

[M+H]+

8.88

326.08214

70.04075

158.97628

92.61411

172.95561

131 Dinotefuran

C7H14N4O3

628234

[M+H]+

2.39

203.11387

129.08985

87.07977

73.06419

114.10301

Diethofencarb *1*

ACS Paragon Plus Environment

110.06048 91.05489

58.06645

Page 29 of 39

Journal of Agricultural and Food Chemistry

+

132 Dioxacarb

C11H13NO4

207247

[M+H]

133 Dioxathion

C12H26O6P2S4

93049

[M+Na]+

134 Diphenamid

C16H17NO

4671648

[M+H]

135 Diphenylamine

C12H11N

136793

[M+H]

136 Dipropetryn

C11H21N5S

137 Disulfoton

4.46

224.09173

93.07039

165.05453

121.06499

79.05486

9.13

478.99797

114.96160

343.13097

271.02187

171.02375

+

7.19

240.13829

134.09653

167.08554

+

7.93

170.09643

93.05788

95.04972

92.05006

105.04516

12591238

[M+H]+

8.14

256.15904

144.03388

214.11219

172.06516

186.08082

C8H19O2PS3

37001

[M+Na]

8.78

297.01770

89.04252

283.03015

266.99901

91.05791

138 Ditalimfos

C12H14NO4PS

121872

[M+H]

+

7.98

300.04539

148.03942

130.02903

243.98299

114.96176

139 Dithiopyr

C15H16F5NO2S2

1655285

[M+H]+

9.02

402.06154

354.05819

271.99868

296.03516

248.03404

140 Diuron

C9H10Cl2N2O

2455686

[M+H]

+

7.05

233.02429

72.04512

159.97168

92.61785

141 Dodemorph

C18H35NO

4492575

[M+H]+

7.10

282.27914

116.10736

98.09699

69.07062

142 Edifenphos

C14H15O2PS2

5059623

[M+H]+

8.46

311.03238

109.01115

111.02675

283.00115

143 Emamectin B1a

C49H75NO13

620997

[M+H]+

9.25

886.53112

158.11774

82.06587

126.09170

144 EPN

C14H14NO4PS

269990

[M+H]

+

8.88

324.04539

156.98730

296.01422

174.99785

94.04195

145 Epoxiconazole

C17H13ClFN3O

1970029

[M+H]+

8.06

330.08039

121.04514

123.02437

70.04074

129.04494

146 Eprinomectin B1a

C50H75NO14

113065

[M+Na]+

9.85

936.50798

352.17295

490.27772

194.07908

368.16796

147 EPTC

C9H19NOS

263595

[M+H]

+

8.38

190.12601

95.04971

141.00046

105.04518

128.10720

148 Esprocarb

C15H23NOS

295160

[M+H]+

9.25

266.15731

91.05501

71.08641

196.07962

65.03947

149 Ethidimuron

C7H12N4O3S2

1717012

[M+H]+

4.07

265.04236

208.02100

114.01245

161.97902

74.00661

150 Ethiofencarb

C11H15NO2S

201047

[M+H]+

6.56

226.08963

181.16995

105.03396

107.04951

128.14347

151 Ethiofencarb-sulfone

C11H15NO4S

510075

[M+H]+

3.92

258.07946

107.04946

201.05793

79.05476

152 Ethiofencarb-sulfoxide

C11H15NO3S

721574

[M+H]+

4.05

242.08454

107.04951

185.06303

164.07045

153 Ethiolate

C7H15NOS

56134

[M+H]+

7.11

162.09471

100.07624

72.04512

134.10010

154 Ethion

C9H22O4P2S4

956632

[M+H]+

9.27

384.99489

114.96164

142.93847

170.96977

199.00102

155 Ethiprole

C13H9Cl2F3N4OS

805620

[M+H]+

7.58

396.98990

254.96987

350.94801

227.95893

212.94794

156 Ethirimol

C11H19N3O

5333439

[M+H]+

5.63

210.16009

140.10698

95.04972

182.12888

105.04522

157 Ethofumesate

C13H18O5S

679156

[M+H]+

7.43

287.09477

121.06516

161.05985

259.06356

133.06498

158 Ethoprophos

C8H19O2PS2

3368491

[M+H]+

8.12

243.06368

130.93866

114.96171

172.09869

215.03237

159 Etobenzanid 160 Etofenprox

C16H15Cl2NO3 C25H28O3

1595789 1190944

[M+H]+ [M+NH4]+

8.44 10.24

340.05018 394.23767

121.02873 177.12728

149.05977 107.04951

179.07031 135.08043

59.04992 183.08035

161 Etoxazole

C21H23F2NO2

5131409

[M+H]+

9.56

360.17696

141.01477

177.12755

304.11442

57.07072

162 Etrimfos

C10H17N2O4PS

4807405

[M+H]+

8.38

293.07194

142.99275

265.04059

78.99507

127.01578

163 Famoxadone

C22H18N2O4

505371

[M+Na]+

8.55

397.11588

261.07606

353.12634

168.04180

92.61948

164 Famphur

C10H16NO5PS2

1937683

[M+H]+

6.78

326.02803

93.01064

298.98080

245.01454

217.00837

165 Fenamidone

C17H17N3OS

2209515

[M+H]

+

7.61

312.11651

92.05013

236.11831

65.03939

103.05477

166 Fenamiphos

C13H22NO3PS

3915827

[M+H]+

8.23

304.11308

217.00803

201.98457

234.03448

276.08135

167 Fenamiphos-sulfone

C13H22NO5PS

2800034

[M+H]+

6.32

336.10291

188.04725

266.02470

308.07154

108.05747

168 Fenamiphos-sulfoxide

C13H22NO4PS

3144417

[M+H]

+

6.31

320.10799

251.01380

171.04743

292.07655

108.05747

169 Fenarimol

C17H12Cl2N2O

551679

[M+H]+

8.08

331.03995

268.05232

81.04545

138.99458

259.00766

170 Fenazaquin

C20H22N2O

4699261

[M+H]+

9.96

307.18049

57.07073

161.13259

147.05536

146.10908

171 Fenbuconazole

C19H17ClN4

1121510

[M+H]+

8.19

337.12145

70.04074

125.01555

91.05486

194.04806

172 Fenhexamid

C14H17Cl2NO2

958761

[M+H]+

8.02

302.07091

97.10178

55.05504

142.00558

143.01342

173 Fenoxanil

C15H18Cl2N2O2

1186354

[M+H]+

8.28

329.08181

86.09689

188.98658

141.11460

98.98454

174 Fenoxycarb

C17H19NO4

2479752

[M+H]+

8.28

302.13868

88.03987

116.07088

256.09652

70.02945

175 Fenpiclonil

C11H6Cl2N2

653568

[M+H]+

7.36

236.99808

202.02932

166.05264

174.01060

219.03198

176 Fenpropathrin

C22H23NO3

322882

[M+H]+

9.64

350.17507

125.09620

97.10164

55.05500

177 Fenpropidin

C19H31N

3999294

[M+H]+

7.24

274.25293

147.11690

86.09711

57.07069

119.08591

178 Fenpropimorph

C20H33NO

3439542

[M+H]+

7.44

304.26349

147.11689

116.10744

57.07073

130.12280

179 Fenpyroximate

C24H27N3O4

2374119

[M+H]+

9.67

422.20743

366.14457

138.06625

135.04414

214.09752

180 Fensulfothion

C11H17O4PS2

3767620

[M+H]+

6.98

309.03786

157.03188

281.00655

173.00909

234.96474

181 Fenthion

C10H15O3PS2

1901687

[M+H]+

8.45

279.02730

219.05694

149.02336

169.01401

105.07033

182 Fenthion-sulfone

C10H15O5PS2

2141635

[M+H]

+

6.50

311.01713

142.99279

127.01577

78.99509

297.00149

183 Fenthion-sulfoxide 184 Fentrazamide

C10H15O4PS2 C16H20ClN5O2

3255358 1133020

6.33 8.41

295.02221 197.12845

127.01574 115.05054

279.99880 83.08617

142.99273 87.01950

90.97727 55.05504

Fentrazamide *1*

C16H20ClN5O2

111262

[M+H]+ Fragment [M+H]+

8.47

350.13783

83.08609

154.12246

197.12813

115.05044

Fentrazamide *2*

C16H20ClN5O2

91112

[M+Na]+

8.46

372.11977

219.11050

83.08622

72.04515

154.12286

185 Fenuron 186 Fenvalerate

C9H12N2O C25H22ClNO3

2090099 171341

[M+H]+ [M+NH4]+

4.26 9.87

165.10224 437.16265

72.04510 167.06204

122.97422 125.01529

104.96383 92.61901

120.04471 181.06458

187 Fipronil

C12H4Cl2F6N4OS

428526

[M+NH4]+

8.28

453.97253

367.95019

436.94528

254.96944

289.97568

188 Flonicamid

C9H6F3N3O

780320

[M+H]+

3.23

230.05357

203.04273

174.01618

148.03682

176.03178

189 Fluazifop-butyl

C19H20F3NO4

3970394

[M+H]+

9.13

384.14172

282.07368

91.05489

328.07915

238.04759

190 Flubendiamide

C23H22F7IN2O4S

56441

[M+Na]+

8.34

705.01254

530.97344

255.92559

90.97723

191 Flucarbazone 192 Flucythrinate

C12H11F3N4O6S C26H23F2NO4

180732 380700

[M+H]+ [M+NH4]+

5.39 9.47

397.04242 469.19334

130.06130 181.06479

115.03801 199.09279

73.04043 157.04602

412.15421

193 Fludioxonil

C12H6F2N2O2

480337

[M+NH4]+

7.68

266.07356

245.05572

227.04483

185.05080

158.03988

194 Flufenacet

C14H13F4N3O2S

1919015

[M+H]

+

8.08

364.07374

152.05053

124.05584

194.09748

109.04512

195 Flufenoxuron

C21H11ClF6N2O3

375303

[M+H]+

9.49

489.04352

158.04133

141.01476

306.03053

196 Flumetralin

C16H12ClF4N3O4

16189

[M+H]+

9.57

422.05252

143.00593

197 Flumetsulam

C12H9F2N5O2S

1847110

[M+H]+

4.24

326.05178

129.03868

262.08979

128.03091

134.05866

198 Flumioxazin

C19H15FN2O4

422410

[M+H]+

7.19

355.10886

299.08268

327.11413

107.04972

176.05069

+

ACS Paragon Plus Environment

83.08618

79.05481

Journal of Agricultural and Food Chemistry

Page 30 of 39

199 Fluometuron

C10H11F3N2O

5750961

[M+H]

+

6.61

233.08962

72.04511

160.03682

168.02568

200 Fluopicolide

C14H8Cl3F3N2O

950550

[M+H]+

7.75

382.97271

172.95579

364.96213

212.00873

201 Fluorochloridone

C12H10Cl2F3NO

1412578

[M+H]

+

7.88

312.01643

310.02080

89.01592

292.01013

212.06833

202 Fluoxastrobin

C21H16ClFN4O5

2223981

[M+H]

+

7.90

459.08660

427.06063

188.03819

138.01068

306.06749

203 Fluquinconazole

C16H8Cl2FN5O

849774

[M+H]+

7.95

376.01627

306.98358

349.00531

272.01476

108.02486

204 Fluroxypyr

C7H5Cl2FN2O3

83905

[M+H]

+

5.65

254.97340

180.97304

208.96801

196.96803

236.96278

205 Flusilazole

C16H15F2N3Si

3665125

[M+H]

+

8.27

316.10761

165.06997

187.05864

95.04975

81.00094

206 Flutolanil

C17H16F3NO2

4104236

[M+H]+

7.73

324.12059

242.06120

262.06743

282.07358

65.03936

207 Flutriafol

C16H13F2N3O

2238060

[M+H]

+

6.88

302.10995

70.04076

123.02441

109.04531

233.07743

208 Fomesafen

C15H10ClF3N2O6S

148603

[M+NH4]+

7.60

456.02384

343.99300

222.97677

178.98678

300.00321

209 Fonofos

C10H15OPS2

641857

[M+H]+

8.55

247.03747

126.99781

137.01838

155.02881

108.98747

210 Forchlorfenuron

C12H10ClN3O

2112969

[M+H]

+

6.94

248.05852

129.02153

111.05566

155.00060

211 Fosthiazate

C9H18NO3PS2

1166298

[M+H]+

6.64

284.05385

104.01695

227.99128

199.95986

212 Fuberidazole

C11H8N2O

4578802

[M+H]+

4.04

185.07094

157.07602

156.06813

130.06527

213 Furalaxyl

C17H19NO4

3482757

[M+H]+

7.57

302.13868

95.01343

242.11774

270.11269

214 Furathiocarb

C18H26N2O5S

2205451

[M+H]+

9.14

383.16352

195.04745

167.05250

164.08319

252.06880

215 Griseofulvin

C17H17ClO6

2739903

[M+H]+

6.86

353.07864

69.03429

165.05476

215.01068

285.05252

216 Halofenozide

C18H19ClN2O2

201565

[M+Na]+

7.59

353.10273

231.06608

72.08156

297.04031

145.02617

217 Haloxyfop

C15H11ClF3NO4

263194

[M+H]+

8.41

362.04015

316.03482

91.05491

272.00856

288.00356

218 Heptenophos

C9H12ClO4P

1024884

[M+H]+

7.13

251.02345

127.01571

125.01557

89.03924

99.00018

219 Hexaconazole

C14H17Cl2N3O

1286142

[M+H]+

8.70

314.08214

70.04076

300.06208

158.97637

220 Hexaflumuron

C16H8Cl2F6N2O3

98440

[M+H]

+

8.92

460.98889

158.04105

141.01450

277.97525

221 Hexazinone

C12H20N4O2

3773313

[M+H]+

6.14

253.16590

171.08776

71.06114

85.07671

222 Hexythiazox

C17H21ClN2O2S

1558590

[M+H]+

9.45

353.10850

168.05745

228.02440

151.03091

194.03685

223 Imazalil

C14H14Cl2N2O

2457590

[M+H]+

6.76

297.05560

158.97634

69.04550

255.00857

200.98688

224 Imazamethabenz-methyl

C16H20N2O3

5372219

[M+H]+

6.25

289.15467

86.09712

144.04450

90.97729

161.07103

225 Imazamox

C15H19N3O4

2439022

[M+H]+

4.81

306.14483

86.09709

193.06099

246.08735

261.12339

226 Imazapyr

C13H15N3O3

3176238

[M+H]+

4.08

262.11862

217.09726

149.03464

86.09709

69.07065

227 Imazaquin

C17H17N3O3

4012048

[M+H]+

6.20

312.13427

199.05034

86.09709

267.11298

252.07678

228 Imibenconazole

C17H13Cl3N4S

622054

[M+H]+

9.29

410.99993

125.01533

171.00271

341.96682

181.98229

229 Imidacloprid

C9H10ClN5O2

768144

[M+H]+

4.04

256.05958

175.09792

209.05894

84.05627

212.05870

230 Imiprothrin

C17H22N2O4

869166

[M+Na]+

8.00

341.14718

191.04285

161.03230

214.08996

231 Inabenfide

C19H15ClN2O2

1201379

[M+H]+

7.47

339.08948

321.07893

80.05019

79.04234

232 Indanofan

C20H17ClO3

538367

[M+H]

+

8.10

341.09390

125.01540

175.07536

187.07522

90.97719

233 Indoxacarb

C22H17ClF3N3O7

744080

[M+H]+

8.87

528.07799

203.01884

168.02104

218.04231

249.04243

234 Ipconazole

C18H24ClN3O

1871879

[M+H]+

8.98

334.16807

70.04075

125.01554

235 Iprobenfos

C13H21O3PS

589643

[M+H]

+

8.37

289.10218

90.97726

220.93455

106.08674

88.07634

236 Iprovalicarb

C18H28N2O3

1186938

[M+H]+

8.07

321.21727

119.08585

116.07104

171.13795

91.05482

237 Isazophos

C9H17ClN3O3PS

3895378

[M+H]+

7.93

314.04895

119.99630

114.96179

162.04295

272.00205

238 Isocarbamid

C8H15N3O2

1982662

[M+H]+

4.99

186.12370

87.05592

123.11711

130.06138

239 Isocarbophos

C11H16NO4PS

46749

[M+Na]+

7.02

312.04299

269.99593

236.00861

240 Isofenphos

C15H24NO4PS

16688

[M+Na]+

8.68

368.10559

326.05876

266.98477

159.99559

203.06793

241 Isofenphos-oxon 242 Isoprocarb

C15H24NO5P C11H15NO2

813570 172234

7.89 6.88

330.14649 137.09609

200.99469 95.04976

229.02594 105.04526

121.02861

219.00505

243 Isopropalin

C15H23N3O4

660439

[M+H]+ Fragment [M+H]+

9.85

310.17613

226.08239

208.07187

268.12926

222.08746

244 Isoprothiolane

C12H18O4S2

1355856

[M+H]+

7.74

291.07193

188.96758

231.01453

144.97776

172.97279

245 Isoproturon

C12H18N2O

3936758

[M+H]

+

6.97

207.14919

72.04511

165.10226

134.09651

246 Isoxaben

C18H24N2O4

3589056

[M+H]+

7.71

333.18088

165.05461

168.04164

150.03107

247 Isoxadifen-ethyl

C18H17NO3

2455421

[M+H]+

8.35

296.12812

204.08078

232.07554

105.03393

248 Isoxaflutole

C15H12F3NO4S

282575

[M+H]+

6.99

360.05119

250.99843

219.97997

189.01591

249 Isoxathion

C13H16NO4PS

4280430

[M+H]+

8.64

314.06104

105.03401

114.96173

113.95393

130.95645

250 Ivermectin B1a

C48H74O14

67523

[M+Na]+

10.53

897.49708

183.06274

329.20838

240.11236

753.41834

251 Kresoxim-methyl 252 Lactofen

C18H19NO4 C19H15ClF3NO7

219009 703041

[M+H]+ [M+NH4]+

8.39 9.20

314.13868 479.08274

222.09119 343.99264

223.09894 222.97664

282.11210 300.00273

194.09636 178.98682

253 lambda-Cyhalothrin

C23H19ClF3NO3

331595

[M+NH4]+

9.72

467.13438

225.02865

181.06472

141.05098

92.62291

254 Linuron

C9H10Cl2N2O2

1853248

[M+H]+

7.50

249.01921

159.97160

182.02416

132.96080

160.97936

255 Lufenuron

C17H8Cl2F8N2O3

249321

[M+Na]+

9.29

532.96764

180.02279

276.78106

256 Malathion

C10H19O6PS2

862284

[M+H]+

7.68

331.04334

99.00810

127.03900

142.99257

301.16928

257 Malathion O-analog

C10H19O7PS

1712744

[M+H]+

6.21

315.06619

99.00811

127.03906

142.99251

117.01853

258 Mandipropamid

C23H22ClNO4

1445477

[M+H]+

7.64

412.13101

125.01539

328.10941

204.10168

356.10419

259 Mefenacet

C16H14N2O2S

3263924

[M+H]+

7.86

299.08488

148.07585

120.08121

192.01161

79.05498

260 Mefluidide

C11H13F3N2O3S

2905394

[M+H]+

6.19

311.06717

135.09185

136.09966

121.07637

178.11015

261 Mepanipyrim

C14H13N3

5504763

[M+H]+

7.94

224.11822

93.07053

165.05479

121.06515

79.05495

262 Mephosfolan

C8H16NO3PS2

4726929

[M+H]+

6.17

270.03820

139.95665

75.02704

196.01936

167.98799

263 Mepronil

C17H19NO2

5264053

[M+H]

+

7.72

270.14886

119.04952

228.10202

91.05484

109.06529

264 Mesotrione

C14H13NO7S

175018

[M+H]+

5.09

340.04855

227.99616

104.01361

77.02665

62.99066

265 Metaflumizone

C24H16F6N4O2

270684

[M+H]+

9.22

507.12502

178.04744

116.04983

287.07892

267.07272

266 Metalaxyl

C15H21NO4

2936330

[M+H]+

7.00

280.15433

220.13334

192.13844

160.11222

248.12822

267 Metazachlor

C14H16ClN3O

811795

[M+H]+

6.90

278.10547

134.09628

210.06767

105.07011

ACS Paragon Plus Environment

114.09175

214.04193

263.10647

Page 31 of 39

Journal of Agricultural and Food Chemistry

+

268 Metconazole

C17H22ClN3O

1675669

[M+H]

269 Methabenzthiazuron

C10H11N3OS

40944

[M+Na]+

270 Methacrifos

C7H13O5PS

134503

[M+H]

271 Methamidophos

C2H8NO2PS

947272

[M+H]

272 Methidathion

C6H11N2O4PS3 C6H11N2O4PS3

Methidathion *1*

8.67

320.15242

70.04076

125.01549

6.83

244.05150

107.96727

113.06011

187.03014

114.06338

+

6.84

241.02941

142.99238

58.06585

142.99238

209.00294

+

1.50

142.00861

112.01614

96.05300

106.04849

78.99498

268389

[M+H]+

7.13

302.96913

145.00633

90.97699

71.02463

286.18051

14335

[M+Na]

7.12

324.95108

71.02478

145.00673

85.04034

199.01511

7.58

226.08963

121.06499

91.05477

169.06807

4.70 4.70

258.07946 275.10600

122.07276 122.07275

201.05786 201.05778

107.04952 258.07868

+

+

273 Methiocarb

C11H15NO2S

603588

[M+H]

274 Methiocarb-sulfone Methiocarb-sulfone *1*

C11H15NO4S C11H15NO4S

48683 25650

[M+H]+ [M+NH4]

Methiocarb-sulfone *2*

C11H15NO4S

4000

[M+Na]+

4.70

280.06140

150.02676

149.02372

233.04016

C11H15NO3S

1536831

[M+H]+

4.39

242.08454

185.06312

170.03960

122.07289

C11H15NO3S

4000

[M+Na]

4.31

264.06649

207.04502

92.62308

249.04279

275 Methiocarb-sulfoxide Methiocarb-sulfoxide *1*

+

+

107.04929 168.06037

276 Methomyl

C5H10N2O2S

14623

[M+H]+

3.15

163.05357

135.04408

133.02833

95.04954

88.02202

277 Methoprotryne 278 Methoxyfenozide

C11H21N5OS C22H28N2O3

6214086 1387524

7.24 7.78

272.15396 313.15467

198.08098 149.05968

170.04961 91.05478

240.12781 133.06486

230.10711 109.06519

Methoxyfenozide *1*

C22H28N2O3

129944

[M+H]+ Fragment [M+H]+

7.78

369.21727

149.05965

133.06479

91.05479

105.07017

Methoxyfenozide *2*

C22H28N2O3

51175

[M+Na]+

7.79

391.19921

149.02355

241.13131

72.08158

219.14940

279 Metobromuron

C9H11BrN2O2

1740936

[M+H]+

6.75

259.00767

169.96004

148.06316

170.96785

91.04229

280 Metolachlor

C15H22ClNO2

3172657

[M+H]+

8.20

284.14118

252.11495

176.14347

134.09655

73.06553

281 Metolcarb

C9H11NO2

167013

[M+H]+

5.79

166.08626

109.06518

118.08656

282 Metominostrobin

C16H16N2O3

3038631

[M+H]+

7.25

285.12337

196.07574

194.06016

166.06523

212.07070

283 Metosulam

C14H13Cl2N5O4S

700677

[M+H]+

6.17

418.01381

174.99514

140.02625

173.98731

189.98222

284 Metoxuron

C10H13ClN2O2

3193945

[M+H]

+

5.32

229.07383

72.04510

156.02093

285 Metrafenone

C19H21BrO5

1087855

[M+H]+

8.73

409.06451

209.08078

226.97009

166.06241

168.96467

286 Metribuzin

C8H14N4OS

801941

[M+H]+

6.13

215.09611

187.10123

96.05303

84.08142

106.04853

287 Mevinphos, cis-

C7H13O6P

375729

[M+H]+

5.10

225.05225

127.01552

90.97714

119.01641

288 Mexacarbate

C12H18N2O2

3233640

[M+H]+

4.58

223.14410

166.12269

151.09920

136.07579

289 Molinate

C9H17NOS

416063

[M+H]+

7.87

188.11036

126.09153

83.08616

98.09695

290 Monocrotophos

C7H14NO5P

742053

[M+H]+

3.58

224.06824

93.07036

127.01553

165.05446

98.06046

291 Monolinuron

C9H11ClN2O2

1535335

[M+H]+

6.56

215.05818

96.05310

142.00410

95.04976

106.04859

292 Moxidectin

C37H53NO8

72031

[M+H]+

10.36

640.38439

622.37349

81.07060

98.06051

199.11196

293 Myclobutanil

C15H17ClN4

114052

[M+H]+

7.88

289.12145

70.04077

90.97729

125.01553

220.93465

294 Naled

C4H7Br2Cl2O4P

74216

[M+H]+

7.16

378.78985

127.01560

173.86325

113.00016

144.98150

295 Napropamide

C17H21NO2

4599805

[M+H]+

8.10

272.16451

171.08042

129.11501

58.06594

74.09717

296 Neburon

C12H16Cl2N2O

3078251

[M+H]

+

8.27

275.07125

88.11277

57.07073

114.09179

58.02958

297 Nitenpyram

C11H15ClN4O2

1834273

[M+H]+

2.97

271.09563

126.01076

56.05033

225.10296

99.09224

298 Nitralin

C13H19N3O6S

294365

[M+H]+

8.28

346.10673

304.05987

242.02308

262.01290

246.01780

299 Norflurazon

C12H9ClF3N3O

3738236

[M+H]+

7.05

304.04590

284.03969

160.03697

140.03075

87.99552

300 Novaluron

C17H9ClF8N2O4

458741

[M+Na]+

9.01

515.00153

301.14091

214.08970

453.36803

493.36026

301 Noviflumuron

C17H7Cl2F9N2O3

139529

[M+Na]+

9.46

550.95822

357.14675

302 Nuarimol

C17H12ClFN2O

1007089

[M+H]+

7.58

315.06950

81.04544

252.08206

226.11569

243.03730

303 Octhilinone

C11H19NOS

155521

[M+H]+

8.23

214.12601

102.00079

71.08596

304 Ofurace

C14H16ClNO3

2088512

[M+H]+

6.21

282.08915

160.11218

254.09423

148.11211

178.12274

305 Omethoate

C5H12NO4PS

7243

[M+H]+

2.32

214.02974

142.99256

127.01554

182.98733

306 Orbencarb

C12H16ClNOS

2510367

[M+H]+

8.76

258.07139

125.01549

100.07622

72.04512

307 Oryzalin

C12H18N4O6S

186740

[M+H]+

8.17

347.10198

305.05504

288.02858

198.01469

245.98158

308 Oxadiazon

C15H18Cl2N2O3

1128319

[M+H]

+

9.32

345.07672

176.95053

219.95634

184.98752

303.02961

309 Oxadixyl

C14H18N2O4

1080759

[M+H]+

5.73

279.13393

219.11291

132.08093

133.08878

149.02343

Oxadixyl *1* 310 Oxamyl

C14H18N2O4 C7H13N3O3S

29674 33455

[M+Na]+

301.11588 237.10159

94.06574 90.97713

138.05510 72.04505

185.08118

215.09180

[M+NH4]+

5.69 2.94

311 Oxamyl-oxime

C5H10N2O2S

539985

[M+H]+

2.25

163.05357

72.04506

90.00134

163.03891

115.05051

312 Oxycarboxin

C12H13NO4S

1037553

[M+H]+

4.89

268.06381

193.01669

175.00601

164.98534

236.07177

313 Oxydemeton-methyl

C6H15O4PS2

1507188

[M+H]+

3.24

247.02221

127.01572

169.00833

142.99269

105.03737

314 Paclobutrazol

C15H20ClN3O

2383134

[M+H]+

7.78

294.13677

70.04075

125.01558

165.04675

315 Pebulate

C10H21NOS

1132381

[M+H]+

8.89

204.14166

128.10713

57.07069

72.04510

316 Penconazole

C13H15Cl2N3

1529285

[M+H]+

8.55

284.07158

70.04073

158.97634

172.99211

317 Pencycuron

C19H21ClN2O

3467102

[M+H]+

8.76

329.14152

125.01555

218.07334

94.06574

106.06566

318 Pendimethalin

C13H19N3O4

200820

[M+H]+

9.46

282.14483

212.06633

69.07057

83.08614

250.17768

319 Penoxsulam 320 Permethrin

C16H14F5N5O5S C21H20Cl2O3

1178621 167050

[M+H]+

484.07086 408.11278

195.07523 183.08033

164.05665 155.08546

139.05026 165.06975

136.06189

[M+NH4]+

6.51 10.29

321 Phenmedipham

C16H16N2O4

515157

[M+H]+

7.19

301.11828

136.03924

168.06537

108.04471

111.04434

322 Phenothrin

C23H26O3

418436

[M+H]+

10.18

351.19547

183.08039

249.12705

156.09321

155.08552

323 Phenthoate

C12H17O4PS2

577409

[M+H]+

8.40

321.03786

107.04954

142.99262

135.04403

79.05487

324 Phorate

C7H17O2PS3

40055

[M+H]+

8.73

261.02010

149.02323

75.02696

121.02866

71.08629

325 Phorate-sulfone

C7H17O4PS3

662550

[M+H]

+

6.87

293.00993

114.96161

171.02375

156.95430

142.99285

326 Phosalone

C12H15ClNO4PS2

950346

[M+H]+

8.72

367.99414

182.00020

114.96162

139.00567

138.01047

327 Phosmet

C11H12NO4PS2

4606

[M+Na]+

7.29

339.98376

160.03950

214.04728

328 Phosphamidon

C10H19ClNO5P

1703392

[M+H]+

5.79

300.07621

127.01587

174.06839

100.07638

72.04524

329 Phoxim

C12H15N2O3PS

904321

[M+H]+

8.64

299.06138

129.04487

95.04970

114.96169

69.07063

ACS Paragon Plus Environment

55.05504

162.09459

Journal of Agricultural and Food Chemistry

Page 32 of 39

330 Picolinafen

C19H12F4N2O2

2475684

[M+H]

+

9.30

377.09077

256.05802

238.04747

359.08012

284.05284

331 Picoxystrobin

C18H16F3NO4

249998

[M+H]+

8.35

368.11042

145.06473

205.08601

117.07008

205.08601

332 Pinoxaden

C23H32N2O4

2828830

[M+H]

+

8.77

401.24348

317.01867

57.07071

289.15476

333 Piperonyl butoxide

C19H30O5

1212232

[M+NH4]

9.35

356.24315

177.09086

91.05788

119.08574

147.08033

8.93

354.13210

170.93358

142.93870

255.02748

212.98063

+

334 Piperophos

C14H28NO3PS2

4328550

[M+H]

+

335 Pirimicarb

C11H18N4O2

5085668

[M+H]

+

5.64

239.15025

72.04513

182.12891

85.07666

336 Pirimiphos-ethyl

C13H24N3O3PS

5695542

[M+H]

+

9.28

334.13488

198.10614

182.12896

170.07469

114.96176

337 Pirimiphos-methyl

C11H20N3O3PS

5011664

[M+H]

+

8.64

306.10358

108.05611

164.11837

67.02986

136.08704

338 Pretilachlor

C17H26ClNO2

3170586

[M+H]+

9.09

312.17248

252.11506

176.14352

147.10434

105.07039

339 Probenazole

C10H9NO3S

346519

[M+H]+

5.81

224.03759

93.07041

165.05454

121.06498

79.05487

340 Prochloraz

C15H16Cl3N3O2

1010063

[M+H]+

8.70

376.03809

308.00030

70.02943

239.97379

85.08915

341 Prodiamine

C13H17F3N4O4

640768

[M+H]

+

9.40

351.12747

250.03094

267.03379

309.08069

291.06999

342 Profenophos

C11H15BrClO3PS

1186540

[M+H]+

9.20

372.94242

302.86389

114.96164

344.91070

128.00246

343 Promecarb

C12H17NO2

845893

[M+H]+

7.79

208.13321

95.04974

109.06524

141.00049

105.04534

344 Prometon

C10H19N5O

17109843

[M+H]+

6.80

226.16624

142.07242

184.11940

100.05108

86.03553

345 Prometryn

C10H19N5S

12845869

[M+H]+

7.87

242.14339

158.04955

200.09659

186.08090

116.02809

346 Propachlor

C11H14ClNO

2430849

[M+H]+

7.03

212.08367

170.03669

95.04968

141.00045

105.04518

347 Propamocarb

C9H20N2O2

2141468

[M+H]+

2.48

189.15975

102.05544

144.10194

74.02434

348 Propanil

C9H9Cl2NO

918751

[M+H]+

7.57

218.01340

161.98712

127.01849

57.03424

349 Propargite

C19H26O4S

929225

[M+NH4]+

9.56

368.18901

175.11173

81.07050

231.17423

350 Propazine

C9H16ClN5

5509102

[M+H]+

7.50

230.11670

146.02280

188.06979

104.00146

79.00643

351 Propetamphos

C10H20NO4PS

65741

[M+H]+

7.88

282.09234

138.01396

222.03521

194.98795

156.02448

352 Propiconazole

C15H17Cl2N3O2

1990486

[M+H]

+

8.55

342.07706

158.97642

69.07065

186.97153

172.95571

353 Propisochlor

C15H22ClNO2

292273

[M+H]+

8.50

284.14118

224.08410

212.08418

148.11242

184.05300

354 Propoxur

C11H15NO3

264836

[M+H]+

6.22

210.11247

95.04952

141.00020

105.04498

111.04426

C11H15NO3

14404

[M+Na]+

6.08

232.09441

174.12771

355 Pymetrozine

C10H11N5O

1062930

[M+H]+

1.89

218.10364

105.04519

107.06082

79.04225

356 Pyracarbolid

C13H15NO2

4324543

[M+H]+

6.17

218.11756

125.05991

71.04985

115.03940

99.08095

357 Pyraclofos

C14H18ClN2O3PS

2678153

[M+H]+

8.64

361.05370

274.99833

138.01061

140.02622

114.96175

358 Pyraclostrobin

C19H18ClN3O4

2964338

[M+H]

+

8.58

388.10586

163.06270

194.08122

149.04713

133.05230

359 Pyraflufen-ethyl

C15H13Cl2F3N2O4

1438535

[M+H]+

8.48

413.02772

338.99103

253.01754

288.99413

260.99937

360 Pyrasulfotole

C14H13F3N2O4S

897710

[M+H]+

5.73

363.06209

250.99849

90.97729

158.96423

113.07141

361 Pyrazophos

C14H20N3O5PS

2371045

[M+H]

+

8.63

374.09340

194.05620

222.08742

176.04558

114.96174

362 Pyridaben

C19H25ClN2OS

1267405

[M+H]+

9.91

365.14489

147.11672

309.08190

132.09336

119.08576

363 Pyridalyl

C18H14Cl4F3NO3

275362

[M+H]+

10.57

489.97527

108.96110

164.03179

183.02093

204.06329

364 Pyridaphenthion

C14H17N2O4PS

4022149

[M+H]+

7.79

341.07194

189.06593

205.04315

92.05009

114.96173

365 Pyridate

C19H23ClN2O2S

726278

[M+H]

10.07

379.12415

207.03190

104.04987

71.08622

57.07066

366 Pyrifenox

C14H12Cl2N2O

2025398

[M+H]+

7.91

295.03995

93.05790

90.97728

158.96403

263.01366

367 Pyrimethanil

C12H13N3

4022132

[M+H]+

7.33

200.11822

107.06077

82.06573

183.09171

125.07114

368 Pyriproxyfen

C20H19NO3

4450260

[M+H]+

9.31

322.14377

96.04499

185.05981

227.10677

134.07284

369 Pyroquilon

C11H11NO

3937315

[M+H]+

5.99

174.09134

132.08086

117.05764

146.09648

156.08097

370 Pyroxsulam

C14H13F3N6O5S

1822439

[M+H]+

6.01

435.06930

195.07520

194.06742

166.07243

124.05079

371 Quinalphos

C12H15N2O3PS

4324655

[M+H]+

8.34

299.06138

147.05532

163.03241

114.96171

242.99889

372 Quinoclamine

C10H6ClNO2

1864347

[M+H]+

5.73

208.01598

105.03395

172.03925

137.01529

95.04970

373 Quinoxyfen

C15H8Cl2FNO

2444549

[M+H]+

9.45

308.00397

196.97948

272.02726

213.98219

228.96929

374 Quizalofop

C17H13ClN2O4

305610

[M+H]+

8.24

345.06366

299.05819

244.03988

255.03208

91.05486

375 Quizalofop-ethyl

C19H17ClN2O4

2471988

[M+H]+

9.08

373.09496

299.05822

91.05482

255.03195

271.06327

376 Resmethrin

C22H26O3

1755653

[M+H]+

10.04

339.19547

171.08045

91.05482

143.08561

128.06228

377 Rotenone

C23H22O6

1519239

[M+H]+

8.13

395.14892

213.09104

192.07821

203.07032

191.07029

378 Saflufenacil

C17H17ClF4N4O5S

141327

[M+H]+

7.27

501.06171

197.97525

348.99936

459.01432

366.02600

379 Schradan

C8H24N4O3P2

4104852

[M+H]

+

5.00

287.13964

135.06825

242.08175

153.07873

380 Secbumeton

C10H19N5O

17114261

[M+H]+

6.73

226.16624

170.10365

100.05103

142.07242

114.06655

381 Sethoxydim

C17H29NO3S

2613453

[M+H]+

9.17

328.19409

178.08596

180.10156

220.13286

110.06025

382 Siduron

C14H20N2O

4730273

[M+H]+

7.51

233.16484

94.06569

137.07099

97.10171

55.05500

383 Simazine

C7H12ClN5

3544060

[M+H]+

6.18

202.08540

132.03239

124.08715

104.00146

96.05616

384 Simeconazole

C14H20FN3OSi

3002056

[M+H]+

8.11

294.14324

70.04074

135.06060

91.05800

115.05463

385 Spinetoram

C42H69NO10

648102

[M+H]+

8.88

748.49942

142.12266

98.09691

386 Spinosyn A

C41H65NO10

856343

[M+H]+

8.62

732.46812

142.12275

98.09701

387 Spinosyn D

C42H67NO10

273086

[M+H]+

8.87

746.48377

142.12281

98.09704

97.06544

388 Spirodiclofen 389 Spiromesifen

C21H24Cl2O4 C23H30O4

670846 15289

9.72 9.55

411.11244 393.20363

71.08623 295.13069

313.03894 313.14118

212.95038 149.02353

295.02852

390 Spirotetramat

C21H27NO5

2171741

[M+H]+ M+Na [M+H]+

7.97

374.19620

216.10205

302.17498

330.20636

270.14879

391 Spiroxamine

C18H35NO2

3796469

[M+H]+

7.58

298.27406

144.13841

100.11267

72.08153

392 Sulcotrione

C14H13ClO5S

812970

[M+H]+

5.87

329.02450

157.04962

111.04450

68.99785

293.04773

393 Sulfentrazone

C11H10Cl2F2N4O3S

384144

[M+NH4]

6.32

404.01570

386.98864

273.03454

306.99539

289.02934

394 Sulfotep

C8H20O5P2S2

15616

[M+H]+

8.43

323.03001

114.96169

171.02394

142.99268

294.99861

395 Sulprofos

C12H19O2PS3

2065219

[M+H]+

9.47

323.03576

139.02128

218.96989

154.97146

236.98040

396 Tau-fluvalinate

C26H22ClF3N2O3

136043

[M+H]+

10.01

503.13438

181.06509

208.07607

153.07014

152.06217

397 Tebuconazole

C16H22ClN3O

1890385

[M+H]+

8.49

308.15242

70.04075

125.01553

151.03075

179.10617

Propoxur *1*

+

+

ACS Paragon Plus Environment

57.07066

97.06536

Page 33 of 39

Journal of Agricultural and Food Chemistry

+

C22H28N2O2

78953

[M+H]

C22H28N2O2

31315

[M+Na]+

399 Tebufenpyrad

C18H24ClN3O

3016581

[M+H]

400 Tebupirimfos

C13H23N2O3PS

3198516

[M+H]

401 Tebuthiuron

C9H16N4OS

402 Teflubenzuron 403 Tembotrione

398 Tebufenozide

8.30

353.22235

133.06479

72.08148

91.05479

105.07030

8.30

375.20430

225.13608

72.08147

203.15415

319.14131

+

9.21

334.16807

145.05245

117.02151

147.11654

132.09319

+

9.30

319.12398

153.10229

277.07699

249.04572

231.03523

4018609

[M+H]+

6.24

229.11176

172.09025

116.02804

89.01740

157.06686

C14H6Cl2F4N2O2 C17H16ClF3O6S

149259 537675

[M+H]

+

[M+NH4]

9.38 7.27

380.98152 458.06465

141.01451 262.03850

158.04107 341.02374

197.96829 305.04698

261.03087

404 Temephos

C16H20O6P2S3

1014195

[M+H]

+

9.23

466.99700

142.99278

437.00429

341.00669

248.98043

405 Tepraloxydim

C17H24ClNO4

887549

[M+H]+

7.95

342.14666

250.14378

166.08640

98.06063

222.14881

406 Terbacil

C9H13ClN2O2

27495

[M+Na]+

6.25

239.05578

182.99289

90.97688

207.09900

407 Terbufos

C9H21O2PS3

23080

[M+Na]+

9.23

311.03335

57.07073

103.05814

92.63040

408 Terbufos-sulfone

C9H21O4PS3

641670

[M+H]

+

7.37

321.04123

114.96151

171.02366

142.99244

409 Terbumeton

C10H19N5O

1205390

[M+H]+

6.67

226.16624

170.10366

142.07330

114.06658

410 Terbuthylazine

C9H16ClN5

6751380

[M+H]+

7.62

230.11670

174.05415

132.03244

79.00643

411 Terbutryn

C10H19N5S

12861680

[M+H]+

7.73

242.14339

186.08165

91.03343

71.06135

412 Tetrachlorvinphos

C10H9Cl4O4P

1330044

[M+H]+

8.34

364.90653

127.01562

203.92950

238.89823

413 Tetraconazole

C13H11Cl2F4N3O

1277613

[M+H]+

8.08

372.02881

158.97643

70.04074

91.05802

150.02316

414 Tetramethrin

C19H25NO4

834893

[M+H]+

9.08

332.18563

164.07058

135.11692

286.18012

107.04958

415 Thiabendazole

C10H7N3S

3305265

[M+H]+

3.78

202.04334

175.03246

131.06045

158.07142

92.04996

416 Thiacloprid

C10H9ClN4S

2775368

[M+H]+

4.98

253.03092

126.01075

186.01392

90.03450

417 Thiamethoxam

C8H10ClN5O3S

837394

[M+H]+

3.38

292.02656

131.96704

211.06482

181.05427

418 Thiazopyr

C16H17F5N2O2S

3110505

[M+H]

+

8.46

397.10037

377.09340

335.04643

61.01107

419 Thidiazuron

C9H8N4OS

795435

[M+H]+

6.04

221.04916

102.01252

127.99150

94.06566

90.97725

420 Thiodicarb

C10H18N4O4S3

572003

[M+H]+

6.51

355.05629

88.02204

107.99390

78.96763

62.00658

421 Thiofanox-sulfone Thiofanox-sulfone *1*

C9H18N2O4S C9H18N2O4S

160590 44113

[M+H]+ [M+NH4]+

4.36 4.32

251.10600 268.13255

57.07050 236.07128

76.03978

90.97705

57.07057

422 Thiofanox-sulfoxide

C9H18N2O3S

82788

[M+H]+

4.11

235.11109

104.01675

57.07060

423 Thionazin

C8H13N2O3PS

1427587

[M+H]+

6.96

249.04573

113.01700

114.96151

192.98297

97.04004

424 Tolclofos-methyl

C9H11Cl2O3PS

695401

[M+H]+

8.73

300.96163

142.99245

174.97099

286.94546

78.99491

425 Tolfenpyrad

C21H22ClN3O2

1420433

[M+H]

+

9.27

384.14733

197.09585

145.05247

117.02155

154.07744

426 Tralkoxydim

C20H27NO3

2969368

[M+H]+

9.40

330.20637

284.16387

138.05475

96.04479

99.03935

427 Triadimefon

C14H16ClN3O2

1501570

[M+H]+

7.80

294.10038

69.07051

197.07251

115.07551

141.00991

428 Triadimenol

C14H18ClN3O2

100376

[M+H]

+

7.97

296.11603

70.04061

264.19285

222.12001

429 Tri-allate

C10H16Cl3NOS

560196

[M+H]+

9.55

304.00909

142.92142

86.06053

82.94554

430 Triazophos

C12H16N3O3PS

3547248

[M+H]+

7.91

314.07228

162.06587

114.96150

119.06047

92.04994

431 Tribufos

C12H27OPS3

5232775

[M+H]+

9.96

315.10344

187.00086

57.07063

112.92814

259.04047

432 Trichlorfon

C4H8Cl3O4P

645959

[M+H]

+

4.39

256.92985

127.01548

220.95277

78.99487

433 Tricyclazole

C9H7N3S

4373160

[M+H]+

5.22

190.04334

163.03240

95.04969

141.00046

105.04517

434 Trietazine

C9H16ClN5

3664594

[M+H]+

8.05

230.11670

99.09205

202.08532

132.03224

104.00133

435 Trifloxystrobin

C20H19F3N2O4

3643227

[M+H]+

8.93

409.13697

186.05222

145.02570

131.07288

206.08088

436 Trifloxysulfuron

C14H14F3N5O6S

377589

[M+H]+

6.84

438.06897

182.05594

83.02456

176.03165

257.01997

437 Triflumizole

C15H15ClF3N3O

808520

[M+H]+

9.00

346.09285

278.05487

69.04545

73.06534

438 Triflumuron

C15H10ClF3N2O3

902300

[M+H]+

8.65

359.04048

156.02069

138.99424

113.01536

439 Trifluralin

C13H16F3N3O4

16607

[M+H]+

9.59

336.11657

294.06971

245.05338

217.02206

440 Triforine

C10H14Cl6N4O2

72431

[M+Na]+

7.21

454.91401

315.95658

351.93322

68.01134

409.89151

441 Trimethacarb

C11H15NO2

485745

[M+H]+

7.02

194.11756

137.09605

122.07284

442 Trinexapac-ethyl

C13H16O5

955069

[M+H]+

7.13

253.10705

69.03426

207.06536

183.02894

139.03906

443 Triticonazole

C17H20ClN3O

1263061

[M+H]+

8.03

318.13677

70.04077

125.01557

444 Uniconazole

C15H18ClN3O

1842251

[M+H]+

8.30

292.12112

70.04075

125.01553

445 Vamidothion

C8H18NO4PS2

1238748

[M+H]+

4.47

288.04876

146.06310

118.03218

58.02942

86.06049

446 Vernolate

C10H21NOS

1133084

[M+H]

+

8.86

204.14166

128.10718

86.05611

162.09466

176.14670

447 Warfarin

C19H16O4

2585372

[M+H]+

7.61

309.11214

163.03882

251.07000

147.08038

191.03369

448 Zoxamide

C14H16Cl3NO2

1522383

[M+H]+

8.61

336.03194

186.97136

158.97642

203.99801

Tebufenozide *1*

+

208.98306

132.03244

152.02771

128.10690

a

Some pesticides have more than one entry because [M+H]+, [M+NH4]+, and/or [M+Na]+ are used for screening to increase their detectability depending on their ionization form. b c e

Due to in-source significant fragmentation, a major product ion is selected for further fragmentation to generate MS/MS fragments to build compound database. The masses of fragments are corrected based the mass accuracy of precursor or 214.08963. Column number

ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

Page 34 of 39

Table 2. Blind spike testing results Fruit sample and compound name

Blind spike concentration (µg/kg)

RTPa

RTFIb

Apple 3-Hydroxycarbofuran Abamectin B1a Aldicarb Azoxystrobin

20 40 60 80

Yes Yes Yes Yes

Yes Yes Yes Yes

Banana Boscalid Carbaryl Carbendazim Chlorpropham

20 10 15 160

Yes Yes Yes Yes

Yes No Yes Yes

Grape Imidacloprid Iprovalicarb

120 440

Yes Yes

Yes Yes

Orange Methacrifos Methiocarb Methomyl Myclobutanil

30 40 150 270

Yes Yes Yes Yes

Yes Yes Yes Yes

Strawberry Pirimicarb Propamocarb Propoxur Pyraclostrobin

30 50 170 190

Yes Yes Yes Yes

Yes Yes Yes Yes

a b

Blind spike concentration (µg/kg)

RTPa

RTFIb

Brocoli Chlorpyrifos-methyl Permethrin Clothianidin Cyprodinil

180 200 220 240

Yes Yes Yes Yes

Yes Yes Yes Yes

Carrot Deltamethrin Diniconazole Emamectin B1a Fenhexamid Fenpropidin Fenpropimorph Fluroxypyr Imazalil

60 80 100 20 240 160 380 420

Yes Yes Yes Yes Yes Yes Yes Yes

Yes Yes Yes Yes Yes Yes Yes Yes

Lettuce Isoprocarb Malathion Metalaxyl

60 280 410

Yes Yes Yes

Yes Yes Yes

Potato Oxamyl Penconazole

10 110

Yes Yes

Yes Yes

Tomato Pyrimethanil Simazine Spinosyn A Spinosyn D Tebuconazole Tetraconazole Thiabendazole

210 25 50 50 270 70 310

Yes Yes Yes Yes Yes Yes Yes

Yes Yes Yes Yes Yes Yes Yes

Vegetable sample and compound name

RTP: retention time (± 0.5 min) and precursor ion (± 5 ppm). RTFI: retention time (± 0.5 min) and fragment ion (± 5 ppm).

ACS Paragon Plus Environment

Page 35 of 39

Journal of Agricultural and Food Chemistry

Full MS-SIM (70,000 FWHM. Mass range: m/z 100 – 1000) DIA-1 DIA-2

Mass range: m/z 100 – 500 m/z 25 in 16 loop counts

Mass range: m/z 500 – 900 m/z 100 in 4 loop counts

Figure 1 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

Figure 2

ACS Paragon Plus Environment

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Page 37 of 39

Figure 3

Journal of Agricultural and Food Chemistry

ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

Figure 4

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Page 39 of 39

Journal of Agricultural and Food Chemistry

TOC Graphic

Compound Database

Individual pesticide standards by UHPLC/ESI Q-Orbitrap Full MS/ddMS2

MS Library

Samples by UHPLC/ESI Q-Orbitrap Full MS/DIA

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