Derivatization Non-targeted Screening of Acids in Oilfield Refinery

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Energy and the Environment

Derivatization Non-targeted Screening of Acids in Oilfield Refinery Wastewater: Identification and Behaviors of Recalcitrant Chlorinated Naphthenic Acids Beili Wang, Hongyang Cui, Hang Liu, and Yi Wan Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.8b05310 • Publication Date (Web): 16 Dec 2018 Downloaded from http://pubs.acs.org on December 17, 2018

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Environmental Science & Technology

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Derivatization Non-targeted Screening of Acids in Oilfield Refinery Wastewater:

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Identification and Behaviors of Recalcitrant Chlorinated Naphthenic Acids

3

Beili Wang, Hongyang Cui, Hang Liu, Yi Wan*

4

1Laboratory

5

Peking University, Beijing 100871, China

6 7

for Earth Surface Processes, College of Urban and Environmental Sciences,

(Received

)

*Address for Correspondence:

8 9 10 11 12 13 14

Address for Correspondence

15

Dr. Yi WAN

16

College of Urban and Environmental Sciences

17

Peking University

18

Beijing 100871, China

19

TEL & FAX: 86-10-62759126

20

Email: [email protected]

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1 ACS Paragon Plus Environment


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ABSTRACT

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The non-targeted scanning chemical profiling approach has shown great potential to

24

identify unknown pollutants or novel biological markers; however, the structure identification

25

of unknown compounds is a challenge. In this study, a carboxyl-specific derivatization

26

reagent, N-(4-aminomethylphenyl) pyridinium (AMPP), was coupled with QTOF-MSE-MS

27

scanning to establish a high-throughput non-targeted scanning method for acid compounds.

28

The scanning method can isolate the precursor by data-independent acquisition and can select

29

all of the acid compounds based on the characteristic fragment generated from the

30

derivatization reagent. The method was applied to scan naphthenic acid fraction compounds

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in petroleum refinery wastewater and identify 70-126 NAs, 30-68 oxy-NAs, 54-60 NAs

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containing nitrogen, and 66-75 NAs containing both nitrogen and oxygen. Chlorinated NAs

33

(Cl-NAs) including monochlorinated NAs (Cl-NAs), monochlorinated hydroxylated NAs

34

(Cl-OH-NAs), and dichlorinated dihydroxylated NAs (Cl2-(OH)2-NAs) were firstly identified

35

with the aid of chlorine isotopic patterns. The Cl-NAs might be naturally presented in crude

36

oil together with NAs. Occurrences and mass balances of Cl-NAs were further assessed in the

37

wastewater treatment plant in north China. The total concentrations of ∑Cl-NAs were

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estimated to be 12±7.8-18±17 µg/L and 8.5±2.0-68±35 µg/g in the wastewater and solid

39

samples, respectively. The removal efficiencies of Cl-NAs (-29.9 to 34.3%) were much lower

40

than those of NAs, suggesting the high recalcitrance of chlorinated compounds during the

41

treatment processes. The estimated mass loss fractions due to degradation for Cl-NAs were

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26.5-53.4% of initial loadings, and relatively high fractions (32.1-56.8%) were observed in

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the effluent directly discharged to the environment. Advanced treatment techniques are 2 ACS Paragon Plus Environment

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needed to effectively reduce the persistent Cl-NAs in the wastewater.

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Keywords: Non-targeted screening, Naphthenic acids, Derivatization, Mass balance,

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Chlorination



47

Introduction

48

Naphthenic acids (NAs) are an acid-extractable fraction of petroleum, and they have been

49

found to be important pollutants in wastewater discharged from various petroleum

50

industries.1-3 NA compounds include components with the molecular formula of CnH2n+zO2,

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where n and z is the carbon number and hydrogen deficiency, respectively. Based on the

52

results of recent studies, these acid-extractable fraction compounds include acidic compounds

53

containing nitrogen and/or sulfur atoms and have various degrees of oxidization, unsaturation,

54

and aromaticity.4-7 For example, oxy-NAs, considered to be the degradation products of NAs,

55

were found to exhibit higher estrogenic activities than the parent compounds.8-11 These

56

findings highlight the need for broader identification of the components of NA fraction

57

compounds (NAFCs) in the environment.

58

The ionization method is essential for the reliable characterization of NA mixtures with

59

mass spectrometry (MS). The widely used electrospray ionization (ESI) and atmospheric

60

pressure chemical ionization (APCI), together with high-resolution MS (HRMS), have greatly

61

facilitated the identification of the elementary compositions of the known NAFCs, but they

62

yield little or no fragmentation for elucidating the molecular structures of the pollutants.1-2 In

63

comparison, derivatization coupled with gas chromatogram MS (GC-MS) or liquid

64

chromatogram MS (LC-MS) has been shown to be more sensitive and selective for the

65

characterization of unknown structures of NAFCs, discovering various structures of

66

individual NAs.8,

67

pyridinium (AMPP), was synthesized that can specifically react with the carboxyl group, and

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it is effective for the structure identification of all fatty acids, because the derivatives

9, 12-14

Recently, a new derivatization reagent, N-(4-aminomethylphenyl)


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generated abundant charge-remote fragmentations.15-18 AMPP could thus enable fragments to

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be yielded from the derivatized NAs and could facilitate the identification of unknown

71

NAFCs in various environmental matrixes.

72

The chemical profiling approach based on HRMS scanning, called non-targeted scanning,

73

has shown great potential to identify unknown pollutants or novel biological markers.19-21

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This approach differs from target ion monitoring, in which only the characteristic ions or ion

75

transitions of target analytes are monitored. Recently, the non-targeted method successfully

76

identified various unknown organo-bromine and organo-iodine compounds in environmental

77

samples based on the isotope features of bromine and iodine.22-24 Precursor ions were

78

analyzed by data-independently acquisition (DIA) mass spectrometry. Halogenated ions were

79

identified based on the characteristic product-ions of bromine or iodine. However, for

80

non-halogenated compounds without characteristic product-ions, it is impossible to select the

81

precursor ions of interest from the thousands of signals obtained. Derivatizations could help

82

resolve the problem because the derivatives, such as AMPP, dansyl chloride etc., can react

83

specifically with certain function groups and generate identical product-ions from the

84

collision energy,10,

85

scanned signals. It has been reported that AMPP could react with the carboxyl group and form

86

product-ions with m/z of 169.0891 and 183.0922.15-18 Thus, derivatization coupled with a

87

nontargeted data acquisition strategy could facilitate the scanning the NAFCs in an effort to

88

identify the unknown carboxylic acid compounds.

15

which could help select the ions of interest from the thousands of

89

To test the hypothesis, this study established a highly sensitive AMPP derivatization

90

method for NAs, which was incorporated with QTOF-MSE-MS to high-throughput scan all of 5 ACS Paragon Plus Environment


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the acid compounds. The method was used to scan the unknown acid pollutants in samples

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from a wastewater treatment plant in a petroleum refinery in north China, and to identify the

93

existence of chlorinated NAs. Mass balances of chlorinated NAs in the wastewater treatment

94

plant were further assessed, and the compounds were found to be highly persistent during the

95

various treatment processes. Advanced treatment techniques were likely needed to effectively

96

remove the identified recalcitrant compounds. The organic chlorides were naturally presented

97

in trace amounts in crude oil, and identifications of the chlorinated compounds has been

98

rarely conducted as a result of the complex of crude oil.25-26 The results of this study is also

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beneficial for eliminations of the organic chlorides in petroleum, which caused serious

100

corrosion in the refinery facilities.25-26

101 102

Materials and methods

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Chemicals and reagents.

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The used chemicals and reagents were shown as follows. 1-adamantaneacetic acid,

105

trans-4-pentylcyclohexane carboxylic acid, cis- and trans- 4-n-propylcyclohexanecarboxylic

106

acid, 2-hexyldecanoic acid, decannoic acid and the commercial mixture of NAs were

107

purchased from TCI (Tokyo Chemical Industry Co., Tokyo, Japan). Cyclohexane pentanoic

108

acid,

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-amino-methyl] aniline were obtained from Sigma Aldrich (Oakville, ON, Canada).

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2,4-dinitrochlorobenzene (Cl-DNB) and 1-methyl-1-cyclohexane carboxylic acid were

111

obtained from Alfa Aesar (Ward Hill, MA). Trans-4-tert-butylcyclohexanecarboxylic acid

112

was purchased from Acros Organics (Morris Plains, NJ). 1-adamantane carboxylic acid,

5-beta-cholanic

acid,

1,2,3,4-tetrahydro-2-naphthoic


acid,

and

4-[(N-Boc)

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N,N-dimethyl formamide and N-hydroxybenzotriazole (98%) were purchased J&K Chemical

114

(Beijing, China). Methanol, hexane, chloroform, ethyl acetate (EA), diethyl ether, methyl

115

tert-butyl ether (MTBE) and absolute ethanol were purchased from Fisher Chemicals (Fair

116

Lawn, NJ). [3-(dimethylamino) propyl] ethyl carbodiimide hydrochloride (EDC) was

117

obtained from Sinopharm Chemical Reagent Co., Ltd. n-[4 (Aminomethyl) phenyl]

118

pyridinium (AMPP) was synthesized by the method described previously.15, 17 HPLC grade

119

ammonium acetate was obtained from Dima-Tech Inc. (Richmond Hill, ON, Canada).

120

Ammonia and hydrochloric acid were obtained from Beijing chemicals (Beijing, China). A

121

water purification system of Milli-Q Synthesis was applied to produce distilled water

122

(Millipore, Bedford, MA).

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Sample collection

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The wastewater and sludge samples were collected from a wastewater treatment plant

125

that processes petroleum refinery water from oil production platforms in north China. The

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behaviors and mass balance of the NAs have been investigated previously in the plant.27 The

127

plant’s treatment consists of physicochemical treatment units (gravity setting, coagulation,

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walnut shell filtration, flotation) and an activated sludge system. The activated sludge system

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is composed of anaerobic and aerobic bioreactors, and the dehydrated sludge were not used

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for agricultural field augmentation. The hydraulic retention time (HRT) was 3.5 h in each

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physicochemical treatment tank, 11-16 h in the anaerobic and aerobic treatment system, and

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the sludge retention time was around 11-12 days in the plant. About 3-6 tons of primary

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sludge were pumped into the dewatering room from gravity and coagulation chambers once a

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month, and approximately 0.2 ton/month of sludge was produced in the activated sludge 7 ACS Paragon Plus Environment


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system. After the activated sludge reactor, the final effluent of secondary clarification tank

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was discharged into the environment.

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To investigate the fates of chlorinated NAs in the wastewater treatment plant, wastewater,

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suspended solids, and sludge samples were taken from each treatment unit in 15th May, 2013

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and 15th May, 2014. A composite water sample (12 h) for each sampling location was

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collected by mixing four water samples taken with a sampling interval of 3 h. 500 mL of

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brown glass bottles were prewashed with methanol and deionized water and used for

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collection of the water samples. All water samples were immediately transported to local

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laboratory and extracted within 4 h. The suspended solids were collected by filtering the

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water samples with GF/C 1.2 μm glass microfiber filters (Whatman, Maidstone, UK). The

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dewatered and excess sludge were taken from the outlets of the physicochemical treatment

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tanks and activated sludge tanks, respectively. The cartridges, glass filters and sludge samples

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were kept at -20 C prior to analysis. During the sampling time, the treatment capacity of

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wastewater of the plant was about 13,000 m3/d, and the mean nitrogen concentrations were

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0.02 mg/L for NO2-N and 0.009 for NO3-N in the effluent of the plant. The petroleum content

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including alkane mixtures extracted by tetrachloromethane was 36 mg/L in the influent, and it

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decreased to 1.5 mg/L after the wastewater treatment.

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Sample preparation

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The methods of extraction of chlorinated NAs from the wastewater and solid samples

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were similar to the analysis of naphthenic acids reported previously.10, 27, 28 About 250 mL of

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filtered wastewater with pH adjusted to about 7 were spiked with two surrogate standards (0.1

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µg of 1-pyrenebutyric acid and 12-oxochenodeoxycholic acid), and then passed through an 8 ACS Paragon Plus Environment

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Oasis MAX cartridge (150 mg, 6 mL, Waters, USA), that was preconditioned by 6 mL of

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methanol and 6 mL of distilled water. The cartridge was rinsed with 6 mL of 5% ammonia,

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and dried under a flow of nitrogen. 6 mL of methanol was used to prewash the MAX

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cartridge, and then the targeted pollutants were eluted with 12 mL of hydrochloric acid

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saturated ethyl acetate (ethyl acetate : 2M HCl =10:1, v/v). The eluate was dried with nitrogen

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and reconstituted in 100 µL of methanol for instrument analysis.

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About 0.5 g sludge and 0.1 g suspended solid samples were freeze-dried and spiked with

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two surrogate standards (5 µg of 1-pyrenebutyric acid and 12-oxochenodeoxycholic acid) for

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Soxhlet extraction. The samples were extracted with 200 mL mixture solution of

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hexane/MTBE/methanol (1:1:1, v/v, pH≈7) for 24 h. The extracts were then concentrated to

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about 2 mL with the rotary evaporation and a gentle stream of nitrogen. After the removal of

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hexane and MTBE, the residues were mixed with 30 mL of distilled water with pH adjusted

169

to about 7 and purified by the MAX cartridge for the UPLC-ESI--QTOF-MS analysis, as

170

reported previously.10

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Derivatization of NA mixtures. The petroleum wastewater extract was dried under the nitrogen gas and reconstituted in

172 173

100

μL

of

acetonitrile/N,N-dimethylformamide

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[3-(dimethylamino)propyl]ethylcarbodiimide hydrochloride aqueous solution (640 mM) was

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added and the mixture was vortexed. Then, 100 μL of N-hydroxybenzotriazole in acetonitrile

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(10 mM) and 100 μL of AMPPin water (30 mM) were added to the mixture. The capped tubes

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were vortexed again, ﬁlled with nitrogen, and incubated at 70°C for 90 min. After incubation

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and cooling, the reaction mixtures were extracted with the solution of CHCl3/MeOH/water 9 ACS Paragon Plus Environment

(4:1,

v/v).

100μL

of


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(1:1:1, v/v/v, 4.5 mL). The bottom layer were taken into a new tube, and the process was

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repeated three times. The combined extract was dried under the nitrogen gas, and resolved in

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100 μL of methanol for the UPLC-QTOF-MS analysis. To assess the synthesis of NA artifacts

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during the extraction and derivatization, NA model compounds were extracted and

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derivatized as described above, and the obtained mass spectrum were similar to those of direct

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derivatized NA-AMPP.

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MSE analysis of derivatized NA mixtures.

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The derivatized Cl-NAs were analyzed using an ACQUITY UPLC system coupled to an

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electrospray ionization (ESI) Xevo QTOF-MS (G2, Waters, Milford, MA). Derivatized NA

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model compounds was separated by a UPLC BEH C8 column (1.7 μm, 2.1×100 mm, Waters).

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The column temperature was 40°C. The injection volume was 3 μL, and the flow rate was

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kept at 0.3 mL min-1. Deionized water containing 10 mM ammonium acetate (A) and

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acetonitrile (B) were used as mobile phases. The gradient was as follows: initial 30% B for

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0.5 min, increased linearly to 80% in 1.5 min, and maintained in 80% for 8 min. B was then

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sharply returned to the initial percentage and held for 3 min to allow for equilibration.

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The MSE (DIA scan) and MSMS analysis were conducted under a positive ion mode.

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MSE experiments were performed by alternating collision energy between high (function 1)

196

and low (function 2) during a single chromatographic run. A generic parameters with two

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scan functions were listed as follows: 45 V of sampling cone voltage, 0.1 s of scan time, a

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trap collision energy of 6V in function 1 and 30-50 V in function 2. The raw data from each

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run were analyzed using Progenesis QI 2.3 software (Waters). For the later MS/MS analysis,

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the collision energy for generation of the mass spectrum was set at 30-50V and the rest 10 ACS Paragon Plus Environment

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conditions were the same as above. The other optimized parameters were 3.0 kV for the

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source capillary voltage, 4.0 V for extraction cone voltage, 100°C for source temperature,

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250°C for desolvation temperature, 50 L/h for cone gas flow rate, and 600 L/h for desolvation

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gas flow rate. Data were collected in the continuum mode. The [M+H]+ ion of

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leucine-enkephalin (200 pg/μL at flow rate of 5 μL/min) was used as a reference lock mass

206

(m/z 556.2771).

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Semi-quantification of Cl-NAs.

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Cl-NAs were further semi-quantified in the non-derivatized samples using the same

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UPLC-QTOFMS method applied in non-targeted analysis. The parent NAs were

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semi-quantified using an internal standard method with calibration against solutions of

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commercial NAs reported in a previous study.10 Cl-NAs were semi-quantified in sample

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extracts relative to the same internal standards using the response factors of NAs, since the

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standards of Cl-NAs were not commercial available. While the estimated concentrations of

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Cl-NAs would be affected by quantification method of NAs, concentration variations of the

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chlorinated compounds in samples during the treatment processes could provide information

216

about removal and mass balance of the chlorinated pollutants in the STP. The whole sample

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preparation processes were validated by analyzing wastewater and sludge samples spike with

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NA model compounds and commercial standard mixture. The standards were spiked into the

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water before solid phase extraction and solid samples prior freeze drying. The recoveries of

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spiked NA model compounds and commercial standard mixtures were in the range of

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62.8±1.1% - 99.5±9.6% and 68.8±5.7% - 96.7±4.2% for wastewater and sludge samples,



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respectively. No chlorinated NAs were found in the spiked samples, suggesting that Cl-NAs

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could not be formed during the sample preparation steps.

224 225

Results and discussion

226

Derivatization of NAs with AMPP.

227

NA mixtures are a group of chemicals that are resistant to ionized fragmentation in the

228

direct negative-ion ESI-MS analysis.1-2 Derivatization coupled with MS analysis has been

229

shown to be superior for identifying the structures of NAs and their analogues in the

230

environmental samples.8, 12-14 Charge-remote fragmentation was found to be effective for the

231

identification of various fatty acids after one-step derivatization of AMPP,15, 29 because the

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charge-carried reagent specifically reacted with acid groups and produced informative

233

fragment patterns for saturated, unsaturated, and modified fatty acids.17,

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AMPP was derivatized with various NA model compounds to explore its potential application

235

in the identification of carboxylic acid groups. As shown in Figure 1, the fragmentation

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pattern of aliphatic chain NAs (fatty acids) were similar to those reported previously.15, 29 The

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most abundant ions were m/z 169.0891 and 183.0922, which were generated from the

238

derivative reagent and identical to various compounds. Notably, distonic ions at m/z 226.1102

239

and 169.0891 were observed as shown in Figure 1, and the structures of these ions have been

240

verified previously.30, 31 The m/z difference between each adjacent product-ion was constant

241

at 14 Da for the saturated fatty acids, suggesting that the methylene group was sequentially

242

lost from the fatty acid carbon chain.15,

243

information about the compound structures compared to the previously used derivative

16, 32

18

In this study,

The derivative reagent provided wealth


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reagent (e.g. BF3-methanol, diazomethane, oxalyl chloride),8,

12

245

identify the alicyclic and/or aromatic NAs in environmental samples.

and it could be applied to

246

Compared to the sequential loss of methylene group in the fatty acid chains (Figure

247

1a-1c), the alicyclic NAs-AMPP presented not only identical and abundant product-ions at

248

m/z 169.0891 and 183.0922, but informative signatures about the alicyclic structures (Figure

249

1d-1k). After derivatization, fragmentation was observed to occur only in the aliphatic chains

250

of the alicyclic NAs, and the alicyclic rings were resistant to fragmentation when the collision

251

energy ranged from 5 to 60 V. Specifically, fragmentation ions generated from the loss of

252

methylene groups were found in NA model compounds of C12H22O2 and three isomers of

253

C11H20O2, and these compounds all contained aliphatic chains in their structures (Figure

254

1e-1h). However, no fragmentation ions besides 169.0891 and 183.0922 could be found for

255

C8H14O2, C11H12O2, C11H16O2, and C12H18O2, which only contain the alicyclic ring structures

256

(Figure 1d, 1i, 1j, and 1k). Thus, based on the mass spectrums of AMPP derivatives of model

257

NA compounds, both the aliphatic and alicyclic NAs-AMPP showed that fragmentations only

258

occurred in the aliphatic carbon chain of the structures, and not happened for the alicyclic

259

rings. The results indicated that the fragmentation of alicyclic NAs-AMPP could be used

260

effectively to determine the existence and positions of alicyclic rings in the NAs. In addition

261

to the abundant fragmentation information, derivatization with AMPPs also greatly improved

262

the analytical sensitivities of NAs with MS analysis. The responses of the NAs-AMPP

263

complex were on average 40 (6-87) folds higher than the non-derivatization compounds for

264

all of the target NA model compounds because the derivatives of NAs were detected as

265

cations rather than anions in the ESI-MS, and AMPP amide group in the derivatives undergo 13 ACS Paragon Plus Environment


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considerable collision-induced dissociation, which greatly enhances the analytical

267

sensitivities.18 Thus, the high sensitivity and abundant product-ions of the AMPP derivatized

268

NAs provide a new method for clarifying the molecular structures of NA mixtures in

269

environmental samples.

270

High-throughput screening of derivatized acids.

271

NAs are highly complex mixtures, and the generally used MS/MS analysis can only

272

analyze limited groups of chemicals, and miss the compounds not selected before the analyses.

273

In this study, AMPP derivatization was incorporated with the UPLC-QTOF-MSE-MS

274

scanning to high-throughput identify the unknown NA compounds in the oilfield wastewater.

275

As shown in Figure 2, the acid compounds in the environmental samples react specifically

276

with AMPP, and the derivatives were further scanned with the MSE mode, which can obtain

277

the precursor ions and corresponding product-ions at the same time. Thus, the AMPP

278

derivatives can generate identical product-ions (m/z 169.0891 and 183.0922) with the high

279

collision energy, which indicates the detection of carboxyl-containing substances in the

280

environmental samples.17 The identification of elementary compositions can be carried out

281

with the accurate mass information of both precursor ions and fragmentations.15,

282

identified acid groups and major functions of the unknown compounds were ultimately

283

validated with the target MS/MS analysis. This non-targeted strategy provided a new way to

284

high-throughput scan compounds with certain function groups in complicated environmental

285

matrixes.

33

The

286

The developed method was applied to scan the acid compounds in the sludge samples

287

collected from the oilfield wastewater treatment plant due to the high concentrations of NAs 14 ACS Paragon Plus Environment

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in the solid samples. The DIA MSE approach help simultaneously acquire all the precursors

289

and their corresponding fragment ions in the derivatized sample extracts by alternating

290

collision energy between high and low during a single chromatographic run. The

291

incorporation of UPLC provided significant qualitative identification advantages, especially

292

for the ions which cannot be resolved by direct MS injection analysis. A 3D ion intensity map

293

was generated for each run, showing the m/z, retention time (min), and intensity with high and

294

low collision energy, which were used to identify the unknown compounds. All the precursor

295

ions with product-ions of both m/z 169.0891 and 183.0922 were firstly selected, and the

296

existences of the ions originated from AMPP suggested that the compounds contained acid

297

function groups. Element analysis was further conducted for these acid compounds. As shown

298

in Figure 3a, 70-126 precursor ions were identified to be NAs, 30-68 ions were oxy-NAs

299

(OxNAs), 54-60 ions were NAs containing nitrogen (NxNAs), and 66-75 ions were NAs

300

containing both nitrogen and oxygen (OxNyNAs). The occurrences of oxygen, nitrogen, and

301

sulfur containing NAs in petroleum-related samples have also been reported in previous

302

investigations.34-37 In addition to the reported NA mixtures, it is interesting that 66-102

303

chlorine-containing NAs (ClxNAs) were identified in the samples with the aid of chlorine

304

isotopic patterns (Figure 3a). As shown in Figure 2, the precursor and some fragmentation

305

ions of the chlorinated acids all exhibited the patterns of chlorine isotopic peaks, suggesting

306

the existences of chlorinated NAs. Cl-NAs can also be separated from most NAs and

307

oxy-NAs in the plot of Kendrick mass defects versus nominal Kendrick mass (Figure 3b). The

308

screened Cl-NAs in a solid sample from the wastewater treatment plant were shown in Table

309

S1. The most frequently identified compounds were three groups of NAs/oxy-NAs containing 15 ACS Paragon Plus Environment


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1 and 2 chlorine atoms including Cl-NAs, Cl-OH-NAs, and Cl2-(OH)2-NAs, of which the

311

structures were exemplified by three chlorinated isomers, as shown in Figure 4. The

312

diagnostic mass fragmentation for the AMPP-derivatized chlorine-containing NAs was the

313

natural loss of HCl moiety and H2O moieties generated with the high collision energy. Taking

314

these results together, the present study identifies the existence and structures of chlorinated

315

NAs in samples from the treatment plant of petroleum refinery wastewater. It has been

316

reported that the organic chlorides were naturally presented in trace amounts in crude oil,25-26

317

thus Cl-NAs might be naturally presented in crude oil together with NAs.

318

Occurrences of chlorinated NAs in oilfield WWTP.

319

The identified chlorinated NAs were targeted screened in aqueous and solid samples from

320

the wastewater treatment plant in a petroleum refinery in north China.27 The behaviors and

321

mass balance of parent NAs have been investigated previously in the plant. The removal

322

efficiencies of the total concentrations of NAs were estimated to be 73±17%, and

323

biodegradation via activated sludge was the major removal mechanism of NAs.27

324

Comparisons of behaviors of NAs and Cl-NAs in the plant could help assess the persistence

325

and removal mechanism of the newly identified Cl-NAs in petroleum refinery wastewater.

326

The mass difference between chlorinated NAs and NAs is an important issue for

327

identification and semi-quantification of signals of chlorinated NAs. The mass differences of

328

ionization ions between detected abundant chlorinated NAs and NAs were in the range of

329

0.0232-0.2132. The mass resolutions required to separate Cl-NAs and NAs, Cl-OH-NAs and

330

NAs, and Cl2-(OH)2-NAs and NAs were in the range of 9400-15000, 1500-4300 and

331

2200-5000, respectively. In this study, the full-scan mode (mass range: 250-1000 Da) was 16 ACS Paragon Plus Environment

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performed at resolution of 25000 to resolve the mass ions of the target chlorinated NAs and

333

NAs. The incorporation of UPLC also helped separate the ions through chromatographic

334

separations.

335

Tables S2 and S3 show the semi-quantified concentrations of Cl-NAs, Cl-OH-NAs, and

336

Cl2-(OH)2-NAs in water and solid samples collected from the individual treatment tanks in

337

the wastewater treatment plant. Concentrations of total chlorinated NAs were in the range of

338

12 ± 7.8-18±17 µg/L and 8.5±2.0-68±35 µg/g in the wastewater and solid samples,

339

respectively. The concentrations of chlorine-containing NAs were estimated to be 3.6-13%

340

and 0.5-10.2% of those of the total NAs previously reported in the wastewater and solid

341

samples, respectively.23 The dominant isomers in the crude oil refinery wastewater were

342

Cl-OH-NAs with Z values of 0, -2, and -4, and those in the solid samples were

343

Cl2-(OH)2-NAs with Z values of 0, -2, and -4. The preferential partition of more chlorinated

344

NAs in the solid phase is consistent with more hydrophobicity of the highly chlorinated

345

compounds. The removal efficiencies, which are estimated by comparing the levels in the

346

refinery influent and secondary effluent, ranged from -29.9 to 34.3% for the chlorinated NAs

347

(Table 1). The Cl-NAs, Cl-OH-NAs, and Cl2-(OH)2-NAs all exhibit recalcitrance during the

348

physical and biological treatment processes. The low removal efficiencies of the chlorinated

349

NAs were significantly different from those of the parent NAs, of which 73±17% were

350

effectively removed in the water phase in the wastewater treatment plant.27 Since NAs has

351

been shown to be effectively removed by biodegradation in the plant,27 the Cl-NAs exhibited

352

high persistence to biodegradation during the active sludge treatment processes. This is



353

consistent with the fact that chlorination would lead to high recalcitrance of compounds to

354

biodegradation in the environment.38

355

Mass flows and mass balance of chlorine-containing NAs were also assessed in the

356

wastewater treatment plant in the petroleum refinery. The variations of mass flux of the total

357

chlorine-containing NAs are shown in Figure 5, and those of the three identified Cl-NAs are

358

shown in Figures S1, S2, and S3. All of the individual chlorinated compounds exhibited

359

similar mass fractionations. The mass flux of the total chlorinated NAs in the raw petroleum

360

wastewater and sorbed phases was 185 g/d and 173 g/d, respectively. The variation

361

percentages of mass flux ranged from -23.6 to 15.3% in the water phases in all of the

362

treatment units, including the physicochemical and biological treatment processes. The

363

relatively low mass flux variability in the all treatment tanks indicated that the adsorption and

364

degradation were of minor importance in the removal of chlorinated NAs in the plant. In the

365

effluent, the mass of total chlorinated NAs was 120 g/d. To better understand the removal

366

mechanisms of chlorinated NAs in the plant, the mass balance of the chlorinated compounds

367

was divided into three fractions (%): secondary effluent (i), dewatered and excess sludge (ii),

368

and total lost (iii) relative to the initial mass flux in the influent (100%) (Figure 6). The

369

estimated mass loss fractions due to degradation for Cl-NAs ranged from 26.5% to 53.4%,

370

while the percentages of sorption removal and sludge discharge were only 6.5-31.8%, and

371

high fractions (32.1-56.8%) of chlorinated NAs in the effluent were discharged to the

372

environment. It is interesting to note that the mass proportion of sludge discharge for different

373

chlorinated NA congeners increased linearly as Z values increased, suggesting that

374

chlorinated NAs with high cyclization are more easily absorbed in the solid phases. The 18 ACS Paragon Plus Environment

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results further demonstrated that chlorinated NAs were persistent during the treatment

376

processes in the plant compared to the parent NAs27 and that advanced treatment techniques

377

were needed to effectively reduce the chlorinated compounds in the wastewater.

378

In summary, a highly sensitive analytical method with AMPP derivatization was

379

established for analysis of NAs and was further incorporated with QTOF-MSE-MS scanning

380

to develop a high-throughput non-targeted scanning method for acid compounds. The method

381

was applied to scan the unknown acid pollutants in the petroleum refinery wastewater and to

382

identify chlorinated NAs in the samples. Occurrences and mass balances of chlorinated NAs

383

were then assessed in the wastewater treatment plant. Chlorinated NAs were found to be

384

highly persistent during various treatment processes compared to the parent NAs, and future

385

study of advanced treatment techniques is needed to effectively remove the chlorinated

386

compounds in the wastewater.

387 388 389

Acknowledgments The research is supported by the Key Program for International S&T Cooperation

390

Projects

of

China

(S2016G6417),

National

Basic

Research

Program

of

China

391

(2015CB458900), National Natural Science Foundation of China (201677003, 41821005),

392

and Henry Fok education foundation (161073).

393 394

Supplementary Data

395

Text, figures, and tables addressing (1) mass flows of Cl-NAs, Cl-OH-NAs,

396

Cl-(OH)2-NAs in the treatment plant, (2) list of screened Cl-NAs in a solid sample; (3) 19 ACS Paragon Plus Environment


397

concentrations of Cl-NAs in the water phases, and (4) concentrations of Cl-NAs in suspended

398

solids and sludge samples.


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REFERENCES

400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441

1. Headley, J. V.; Peru, K. M.; Barrow, M. P. Mass spectrometric characterization of

2.

3. 4.

5.

6.

7.

8.

9. 10.

11.

12.

13.

14.

naphthenic acids in environmental samples: A review. Mass Spectrom. Rev. 2009, 28, 121-134. Headley, J. V.; Peru, K. M.; Barrow, M. P. Advances in mass spectrometric characterization of naphthenic acids fraction compounds in oil sands environmental samples and crude oil-A review. Mass Spectrom. Rev. 2016, 35, 311-328. Barrow, M. P. Petroleomics: Study of the old and the new. Biofules 2010, 1, 651-655. Barrow, M. P.; Witt, M.; Headley, J. M.; Peru, K. M. Athabasca oil sands process water: Characterization by atmospheric pressure photoionization and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Anal. Chem. 2010, 82, 3727−3735. Hughey, C. A.; Galasso, S. A.; Zumberge, J. E. Detailed compositional comparison of acidic NSO compounds in biodegraded reservoir and surface crude oils by negative ion electrospray Fourier transform ion cyclotron resonance mass spectrometry. Fuel 2007, 86, 758−768. Grewer, D. M.; Young, R. F.; Whittal, R. M.; Fedorak, P. M. Naphthenic acids and other acid-extractables in water samples from Alberta: what is being measured? Sci. Total Environ. 2010, 408, 5997-6010. Meshref, M. N. A.; Chelme-Ayala, P.; El-Din, M. G. Fate and abundance of classical and heteroatomic naphthenic acid species after advanced oxidation processes: Insights and indicators of transformation and degradation. Water Res. 2017, 125, 62-71. Rowland, S. J.; West, C. E.; Jones, D.; Scarlett, A. G.; Frank, R. A.; Hewitt, L. M. Steroidal aromatic “naphthenic acids” in oil sands process-affected water: structural comparisons with environmental estrogens. Environ. Sci. Technol. 2011, 45, 9806-9815. Scott, A. C.; Young, R. F.; Fedorak, P. M. Comparison of GC-MS and FTIR methods for quantifying naphthenic acids in water samples. Chemosphere. 2008, 73, 1258-1264. Wang, B. L.; Wan, Y.; Gao, Y. X.; Yang, M.; Hu, J. Y. Determination and Characterization of Oxy-Naphthenic Acids in Oilfield Wastewater. Environ. Sci. Technol. 2013, 47, 9545−9554. He, Y.; Wiseman, S. B.; Hecker, M.; Zhang, X.; Wang, N.; Perez, L. A.; Jones, P. D.; Gamal El-Din, M.; Martin, J. W.; Giesy, J. P. Effect of ozonation on the estrogenicity and androgenicity of oil sands process-affected water. Environ. Sci. Technol. 2011, 45, 6268-6274. Smith, B. E.; Rowland, S. J. A derivatisation and liquid chromatography/electrospray ionization multistage mass spectrometry method for the characterization of naphthenic acids. Rapid Commun. Mass Spectrom. 2008, 22, 3909-3927. Rowland, S. J.; West, C. E.; Scarlett, A. G.; Jones, D.; Boberek, M.; Pan, L.; Ng, M.; Kwong, L.; Tonkin, A. Monocyclic and monoaromatic naphthenic acids: synthesis and characterisation. Environ. Chem. Lett. 2011, 9, 525-533. Hao, C. Y.; Headley, J. V.; Peru, K. M.; Frank, R.; Yang, P.; Solomon, K. R. Characterization and pattern recognition of oil-sand naphthenic acids using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry. J 21 ACS Paragon Plus Environment


442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485

Chromat. A. 2005, 1067, 277-284. 15. Wang, M.; Han, R. H.; Han, X. L. Fatty acidomics: Global analysis of lipid species

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

containing a carboxyl group with a charge-remote fragmentation-assisted approach. Anal.Chem. 2013, 85, 9312-9320. Yang K, Dilthey B G, Gross R W. Identification and quantitation of fatty acid double bond positional isomers: a shotgun lipidomics approach using charge-switch derivatization. Anal.Chem. 2013, 85, 9742-9750. Bollinger, J. G., Rohan, G., Sadilek, M., Gelb, M. H. LC/ESI-MS/MS detection of FAs by charge reversal derivatization with more than four orders of magnitude improvement in sensitivity. J. Lipid. Res. 2013, 54, 3523-3530. Bollinger, J. G.; Thompson, W.; Lai, Y.; Oslund, R. C.; Hallstrand, T. S.; Sadilek, M.; Turecek, F.; Gelb, M. H. Improved sensitivity mass spectrometric detection of eicosanoids by charge reversal derivatization. Anal.Chem. 2010, 82, 6790-6796. Al-Salhi, R. Abdul-Sada, A. Lange, A. Tyler, C. R. Hill, E. M. The xenometabolome and novel contaminant markers in fish exposed to a wastewater treatment works effluent. Environ. Sci. Technol. 2012, 46, 9080−9088. Schymanski, E. L.; Singer, H. P.; Longree, P.; Loos, M.; Ruff, M.; Stravs, M. A.; Vidal, C. R.; Hollender, J. Strategies to characterize polar organic contamination in wastewater: Exploring the capability of high resolution mass spectrometry. Environ. Sci. Technol. 2014, 48, 1811-1818. Schymanski, E. L.; Singer, H. P.; Slobodnik, J.; Ipolyi, I. M.; Oswald, P.; Krauss, M.; Schulze, T.; Haglund, P.; Letzel, T.; Grosse, S.; Thomaidis, N. S.; Bletsou, A.; Zwiener, C.; Ibanez, M.; Portoles, T.; de Boer, R.; Reid, M. J.; Onghena, M.; Kunkel, U.; Schulz, W.; Guillon, A.; Noyon, N.; Leroy, G.; Bados, P.; Bogialli, S.; Stipanicev, D.; Rostkowski, P.; Hollender, J. Non-target screening with high-resolution mass spectrometry: critical review using a collaborative trial on water analysis. Anal. Bioanal. Chem. 2015, 407, 6237-6255. Peng, H.; Chen, C.; Saunders, D. M. V.; Sun, J. X.; Tang, S.; Codling, G.; Hecker, M.; Wiseman, S.; Jones, P. D.; Li, A.; Rockne, K. J.; Giesy, J. P. Untargeted identification of oragno-bromine compounds in lake sediments by ultrahigh-resolution mass spectrometry with the data-independent precursor isolation and characteristic fragment method. Anal. Chem. 2015, 87, 10237-10246. Peng, H.; Chen, C.; Cantin, J.; Saunders, D. M. V.; Sun, J.; Tang, S.; Coding, G.; Hecker, M.; Wiseman, S.; Jones, P. D.; Li, A.; Rockne, K. J.; Sturchio, N. C.; Giesy, J. P. Untargeted screening and distribution of organo-bromine compounds in sediments of Lake Michigan. Environ. Sci. Technol. 2016, 50, 321-330. Peng, H.; Chen, C.; Cantin, J.; Saunders, D. M. V.; Sun, J.; Tang, S.; Coding, G.; Hecker, M.; Wiseman, S.; Jones, P. D.; Li, A.; Rockne, K. J.; Sturchio, N. C.; Cai, M. H.; Giesy, J. P. Untargeted screening and distribution of organo-iodine compounds in sediments of Lake Michigan and the Arctic Ocean. Environ. Sci. Technol. 2016, 50, 10097-10105. Wu, B. C.; Li, Y. F.; Li, X. H.; Zhu, J. H.; Ma, R.; Hu, S. J. Organochlorine compounds with a low boiling point in desalted crude oil: Identification and conversion. Energy & Fuels 2018, 32, 6475-6481. Arjang, S.; Motahari, K.; Saidi, M. Experimental and modeling study of organic chloride 22 ACS Paragon Plus Environment

Page 22 of 32

Page 23 of 32

486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529


27.

28.

29.

30.

31.

32.

33.

34.

35.

36.

37.

38.

compounds removal from naphtha fraction of contaminated crude oil using sintered γ ‑ Al2O3 nanoparticles: Equilibrium, kinetic, and thermodynamic analysis. Energy & Fuels 2018, 32, 4025-6481. Wang, B.L.; Wan, Y.; Gao, Y.X.; Zheng, G.M.; Yang, M.; Wu, S.; Hu, J.Y. Occurrences and Behaviors of Naphthenic Acids in a Petroleum Refinery Wastewater Treatment Plant. Environ. Sci. Technol. 2015, 49, 5796– 5804. Wan, Y.; Wang, B. L.; Khim, J. S.; Hong, S.; Shim, W. J.; Hu, J. Y. Naphthenic acids in costal sediments after the Hebei spirit oil spill: a potential indicator for oil contamination. Environ. Sci. Technol. 2014, 48, 4153-4162. Frankfater C, Jiang X, Hsu F F. Characterization of Long-Chain Fatty Acid as N-(4-Aminomethylphenyl) Pyridinium Derivative by MALDI LIFT-TOF/TOF Mass Spectrometry. J. AM. Soc. Mass Spectrom. 2018, 1-12. Hsu, F. F. Characterization of hydroxyphthioceranoic and phthioceranoic acids by charge-switch derivatization and CID tandem mass spectrometry. J. Am. Soc. Mass Spectrom. 2016, 27, 622-632. Yang, K.; Dilthey, B.G.; Gross, R. W. Identification and quantitation of fatty acid double bond positional isomers: A shotgun lipidomics approach using charge-switch derivatization. Anal. Chem. 2013, 85, 9742−9750. Liu, X., Moon, S. H., Mancuso, D. J., Jenkins, C. M., Guan, S., Sims, H. F., & Gross, R. W. Oxidized fatty acid analysis by charge-switch derivatization, selected reaction monitoring, and accurate mass quantitation. Anal. Biochem. 2013, 442, 40-50. Meckelmann, S. W., Hellhake, S., Steuck, M., Krohn, M., & Schebb, N. H. Comparison of derivatization/ionization techniques for liquid chromatography tandem mass spectrometry analysis of oxylipins. Prostaglandins Other Lipid Mediat. 2017, 130, 8-15. Bataineh, M.; Scott, A. C.; Fedorak, P. M.; Martin, J. W. Capillary HPLC/QTOF-MS for characterizing complex naphthenic acid mixtures and their microbial transformation. Anal. Chem. 2006, 78, 8354−8361. Hindle, R.; Noetheden, M.; Peru, K.; Headley, J. Quantitative analysis of naphthenic acids in water by liquid chromatography-accurate mass time-of-flight spectrometry. J. Chromatogr. A. 2013, 1286, 166-174. Hughey C. A.; Minardi, C. S.; Galasso-Roth, S. A.; Paspalof, G. B.; Mapolelo, M. M.; Rodgers, R. P.; Marshall, A. G.; Ruderman, D. L. Naphthenic acids as indicators of crude oil biodegradation in soil, based on semi-quantitative electrospray in soil, based on semi-quantitative electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Rapid Commun. Mass Spectrom. 2008, 22, 3968-3976. Eckert, P. A.; Roach, P .J.; Laskin, A.; Laskin, J. Chemical characterization of crude petroleum using nanospray desorption electrospray ionization coupled with high-resolution mass spectrometry. Anal. Chem. 2012, 84, 1517-1525. Bhatt, P.; Kumar, M. S.; Mudliar, S.; Chakrabarti, T. Biodegradation of chlorinated compounds – A review. Critical Review in Environ. Sci. Technol. 2007, 37, 165-198.



530 531

Table 1. Removal efficiencies of detected chlorinated naphthenic acids in oilfield refinery wastewater treatments. Total Z=0 Z=-2 Z=-4 Z=-6 Z=-8 Z=-10 Z=-12 Z=-14

Total 6.4 1.7 -29.9 -4.8 23.8 27.9 22.7 27.8 34.3

Cl-NAs -16.9 -24.0 -97.5 -36.5 3.2 18.0 36.3 46.8 37.9

Cl-OH-NAs 9.8 17.8 -4.6 -5.5 39.7 -5.4 14.2 16.6 28.9

Cl2-(OH)2-NAs 39.3 29.6 33.6 44.6 -1.0 75.9 14.2 -5.8 42.0

532 533


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534



535 536 537

Figure 1. Product-ion MS spectra of model aliphatic chain NAs (a-c), alicyclic NAs (d-k) after derivatization with AMPP. The majority of the abundant product-ions after fragmentation with AMPP were assigned and illustrated in the corresponding molecular structures.*: distonic ion. 26 ACS Paragon Plus Environment

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538 539 540 541 542 543 544 545


Figure 2. A schematic of the workflow used to identify chlorinated napthenic acids in oilfield refinery wastewater. *: distonic ion. The UPLC-QTOFMS spectrums show the identifications of Cl-NAs in samples by data-independent acquisition (DIA) MSE approach.



546

547 548 549 550 551

Figure 3. Screened precursor ions and retention time for the extracted chemical features of derivatized NAs, OxNAs, NxNAs, OxNyNAs and ClxNAs in a sample extract a); and plots of Kendrick mass defect versus nominal Kendrick mass for the five groups of acid compounds.


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Figure 4. MS/MS spectra of Cl-NAs (a), Cl-OH-NAs (b) and Cl2-(OH)2-NAs (c) derivatized with AMPP in extracts of sludge samples from the petroleum refinery wastewater plant. 29 ACS Paragon Plus Environment


555 556 557 558 559 560

Figure 5. Mass flows (g/d) of total chlorinated NAs in a petroleum refinery wastewater treatment plant in north China.


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Figure 6. Mass proportions of chlorinated NAs in (i) secondary effluent (Weff), (ii) dewatered sludge (Wsludge), and (iii) total lost (Wlost) relative to the calculated initial loading (100%) in the petroleum refinery wastewater treatment plant, z is hydrogen deficiency of Cl-NAs.



569

TOC

570 571 572 573 574 575


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Derivatization Non-targeted Screening of Acids in Oilfield Refinery

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