Dissipation and Removal of the Etofenprox Residue during

Jul 13, 2015 - The dissipation and removal of the etofenprox residue was studied in spring onion grown under greenhouse conditions. Samples of spring ...
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Dissipation and Removal of the Etofenprox Residue during Processing in Spring Onion Kyu-Won Hwang,†,‡ Woo-Suk Bang,†,§ Hyeong-Wook Jo,‡ and Joon-Kwan Moon*,‡ ‡

Department of Plant Life and Environmental Sciences, Hankyong National University, Ansung, Gyeonggi 456-749, Republic of Korea § Department of Food and Nutrition, Yeungnam University, Gyeongsan, Gyeongbuk 712-749, Republic of Korea ABSTRACT: The dissipation and removal of the etofenprox residue was studied in spring onion grown under greenhouse conditions. Samples of spring onion were collected at 0, 1, 2, 4, 6, 8, 10, 12, and 14 days after last application, and removal rates of etofenprox by washing and drying processes were measured. Samples were extracted with acetone and partitioned with dichloromethane. The dichloromethane layer was then concentrated, cleaned up with florisil column chromatography, and analyzed with high-performance liquid chromatography−ultraviolet detector (HPLC−UVD). At the fortification levels of 0.5, 1.0, and 10 mg/kg, recoveries ranged from 92.0 to 107.7%, with a coefficient of variation of 4.3−7.9% (n = 3). The method limit of quantification (MLOQ) was found to be 0.05 mg/kg in spring onion. The half-lives of etofenprox in spring onion were found to be 9.5 and 7.9 days, at the single or double application rates. Removal rates of etofenprox were 21.6−43.9 and 66.6−88.5% by various washing or drying processes, respectively. KEYWORDS: etofenprox, pesticide residue, dissipation, washing process, drying process

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INTRODUCTION

systems following direct contact or ingestion and is active against a broad spectrum of pests.2 It is used in agriculture, horticulture, viticulture, forestry, animal health, and public health against many insect pests, for instance, Lepidoptera, Hemiptera, Coleoptera, Diptera, Thysanoptera, and Hymenoptera. In agriculture, etofenprox is used on a broad range of crops, such as rice, fruits, vegetables, corn, soybeans, and tea.3,4 It is poorly absorbed by roots, and little translocation occurs within plants. In the public health sector, etofenprox is used for vector control by either direct application in infested areas or indirectly impregnating fabrics, such as mosquito nets. Etofenprox is used at low volumes to control adult mosquitoes, non-biting midges, and biting and non-biting flies and is also used undiluted for ultra-low-volume aerosol applications or diluted with a diluent, such as mineral oil, for direct applications, for the control of pest species in or near residential, industrial, commercial, urban, and recreational areas, woodlands, golf courses, and other areas where these pests are a problem.5 This pesticide is toxic to aquatic organisms, including fish and aquatic invertebrates. Runoff from treated areas or deposition into bodies of water may be hazardous to fish and other aquatic organisms. This insecticide is also highly toxic to bees exposed to direct treatment on blooming crops or weeds. Etofenprox is registered in Korea to control stone leek leafminer (Liriomyza chinensis), beet armyworm (Spodoptera exigua), Spodoptera litura, or greenhouse whitefly (Trialeurodes vaporariorum) in various fruits, vegetables, and grains.6

The use of pesticides in agriculture has led to an increase in farm productivity, so that a relatively small number of farmers can produce a wide variety and abundance of agricultural commodities at a reasonably low cost. The disadvantage of pesticide use is that the residue may remain on agricultural commodities, where it contributes to the total dietary intake of pesticides.1 Etofenprox, 2-(4-ethoxyphenyl)-2-methylpropyl 3-phenoxybenzyl ether, is a pyrethroid derivative, which is used as an insecticide (Table 1). This insecticide disturbs insect nervous Table 1. Physicochemical Properties of Etofenprox

Received: Revised: Accepted: Published: © 2015 American Chemical Society

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May 11, 2015 July 5, 2015 July 13, 2015 July 13, 2015 DOI: 10.1021/acs.jafc.5b02345 J. Agric. Food Chem. 2015, 63, 6675−6680

Article

Journal of Agricultural and Food Chemistry The spring onion (Allium fistulosum) is widely used throughout southeast Asia as well as in the north in China, Korea, and Japan. It is used raw as a herb to give flavor and a touch of bright green color to many soups, noodles, and other dishes. Dried spring onion is used for seasonings or condiments to improve the flavor and pungency of food, which have some potential benefits for human health.7,8 Because pesticides are a toxic compound used to kill pests in crops, when it remains on treated crops, the presence of harmful pesticide residues in food has caused a great concern among consumers. Food safety is an area of growing worldwide concern on account of its direct bearing on human health. Food processing treatment such as washing, peeling, canning, or cooking leads to a significant reduction of pesticide residues.9 There are no publications on the dissipation of etofenprox in spring onion and residue removal during processing. In this paper, we report residue decline in green onion after treatment of etofenprox with two different application rates and reduction of residual etofenprox on spring onion by various washing and drying processes with a heating oven or a freeze dryer.

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were gradually increased from 25.5 g at 0 DAT to 45.5 g at 14 DAT (Figure 1).

Figure 1. Growth rate of spring onion during cultivation [means ± standard deviation (SD); n = 10].

MATERIALS AND METHODS

Chemicals and Reagents. The analytical standard of etofenprox (97.7%) was purchased from Fluka (Switzerland). The etofenprox formulation with 20% emulsifiable concentrate (EC) (Kyung Nong Co., Ltd., Korea) was purchased from a local market. Acetonitrile, dichloromethane, ethyl acetate, n-hexane, and methanol were highperformance liquid chromatography (HPLC)-grade (Burdick and Jackson, Ulsan, Korea). Sodium chloride [Extra Pure (EP) grade] and sodium sulfate (EP grade) were from Samchun Pure Chemical Co., Ltd. (Pyeongtaek, Korea). Florisil (0.15−0.250 mm) was purchased from Merck KGaA (Germany) and activated by drying at 130 °C for over 5 h. Filter papers (GF/A) were from Whatman International, Ltd. (Maidstone, U.K.). The vacuum rotary evaporator was from Heidolph (Germany). The Waring blender was from Zymark (Germany). A FO600M drying oven was from Jeio Tech, Korea. The PVTFD20R freeze dryer was from ilShin Biobase, Korea. Field Experiment. The field trial on spring onion (Jeju Island variety) was carried out in a greenhouse located in Cheong-ju, Republic of Korea. Treatment (control, single application, and double application) was made in triplicate of 30 m2 plot size with a total of 90 m2 for each treatment. Each randomized plot was separated by a buffering area of 5 m2 to avoid cross-contamination by drift, etc. The first application was sprayed to onions 20 days after germination, and the second application was performed after 7 days. The planting density of spring onion was 15 × 15 cm, and over 1300 bunches of onions were evenly distributed for each test plot (30 m2). The temperature and relative humidity in the greenhouse were continuously measured during the spring onion cultivation period using an electric data logger (Lascar, China). Pesticide Application and Sample Collection. Etofenprox with 20% EC with the product name of “Severo” (Gyung Nong Co., Ltd., Korea) was sprayed at a standard rate (20 mL/20 L) 1 time or 2 times with a 7 day interval using a pressurized hand-held sprayer. The total volume of spray solution applied to each 30 m2 plot was 10 L, which is equivalent to 200 mg of etofenprox per plot. To study the dissipation pattern, 2 kg of spring onion samples was collected randomly from each treated plot as well as from the untreated plot at 0, 1, 4, 6, 8, 10, 12, and 14 days after final treatment (DAT). Immediately after picking, the samples were put into polyethylene bags and transported with ice to the laboratory, where the samples were homogenized. The homogenate of each sample was then placed into polyethylene bottles and frozen at −20 °C until analysis. For the processing experiment, 12 DAT samples were collected and processed with washing or drying. Growth Condition during Cultivation. During spring onion cultivation, the greenhouse air temperature range was 12.5−20.8 °C and humidity was 63.6−90.5%. The weights of collected spring onion

Measurement of Instrumental Sensitivity and Calibration Curve Linearity. The etofenprox analytical standard (97.7%, 10.24 mg) was dissolved in 100 mL of acetonirile to make stock 100 mg/L solution. From this stock solution, a working standard solution (50 mg/L) was prepared by dilution with acetonirile and then serially diluted to obtain a standard solution of 10, 5, 2.5, 1.0, 0.5, and 0.25 mg/L. An aliquot of 10 μL was analyzed using HPLC, and a standard calibration curve was prepared on the basis of the peak area. HPLC Analysis Condition. HPLC was performed using a HP1200 system (Hewlett-Packard, Palo Alto, CA) with a Phenomenex GeminiNX C18 (4.6 × 150 mm, 3 μm, Phenomenex, Torrance, CA) column. Mobile phases consisted of water (A) and acetonitrile (B) acidified with 0.1% acetic acid. The gradient condition used was from 70:30 (A/ B, at 0−3 min) to 15:85 (at 12−17 min) and 70:30 (at 18−20 min). The flow rate was 0.8 mL/min. The injected sample (10 μL) was monitored at the wavelength of 235 nm. Recovery Test of Etofenprox from Samples. To a sample (20 g) of homogenized spring onion, a standard solution of etofenprox was spiked at 0.5, 1.0, and 10 mg/kg. Then, the sample was extracted with 100 mL of acetone by homogenation in a Waring blender for 2 min, followed by filtering into a round-bottom flask of 500 mL capacity under vacuum through a Whatman filter paper no. 2. The container and filter cakes were washed twice with 50 mL of acetone, and the combined extracts were collected in a 500 mL flask. The filtrate was redissolved in 100 mL of dichloromethane (DCM). Then, 10 mL of saturated NaCl solution and 90 mL of water were added in the separatory funnel, and the funnel was shaken. After shaking, the lower DCM layer was drained into a 500 mL flask through anhydrous sodium sulfate supported on a prewashed glass wool in the conical funnel. This procedure was repeated with 100 mL of DCM. Then, extracts were collected, pooled, and concentrated to dryness using a vacuum evaporator at 40 °C. Then, the residue was redissolved in 10 mL of hexane. The concentrated extract was transferred to a chromatographic glass column, which was packed with 10 g of florisil in the bottom and 3 g of sodium sulfate in the top, with hexane as the packing solvent. The packed column was washed with 50 mL of hexane prior to use, and the concentrated extract was loaded on the top of the column and washed with 100 mL of hexane. Then, etofenprox was eluted with 100 mL of 5% ethyl acetate in hexane. Eluate was concentrated using a rotary vacuum evaporator, and the residue was redissolve in 4 mL of acetonitrile for analysis. Spring onion samples collected from the treated field were prepared with the method described above and analyzed using HPLC. 6676

DOI: 10.1021/acs.jafc.5b02345 J. Agric. Food Chem. 2015, 63, 6675−6680

Article

Journal of Agricultural and Food Chemistry Dissipation and Biological Half-Life on Spring Onion. Dissipation of pesticide on spring onion was determined by firstorder kinetic regression analysis with the following model:

Ct = C0e

MLOQ (mg/kg) = (LOQ × final solution volume) /(injection volume × sample weight)

−kt

MLOQ (mg/kg) = (2.5 ng × 4 mL)/(10 μL × 20 g)

where Ct is the concentration of pesticide at any time t, C0 is the initial concentration, and k is the rate of constant in day−1. The biological half-life (DT50), which is the time at which the concentration of initial deposits reaches the 50% level, was determined by the following equation:

= 0.05 mg/kg

The MLOQ value for etofenprox calculated using the equation was 0.05 mg/kg. This value satisfied the criteria of the Korea Food and Drug Administration (KFDA), which are below 0.05 mg/kg or half of the maximum residue limit (MRL).14 The recovery was validated to estimate the efficiency of extraction and purification procedure before the determination of quantities of pesticides on collected samples. The untreated samples were fortified with etofenprox standard solution at three different levels and were analyzed after pretreatment. Average recovery ranged from 92.0 to 107.7% (Table 2), with

DT50 = ln 2k−1 = 0.693/k Washing Process with Running Tap Water. The spring onion samples (1 kg) at 12 DAT were washed with running tap water for 1 min. The flow rate of the running tap water was regulated to 1 L/10 s. Then, the spring onion was air-dried under room temperature. Tap Water Bath. The spring onions (1 kg) at 12 DAT were rinsed in a 6 L of tap water for 1 min, after which the onions were removed, the water was allowed to drain, and the onions were allowed to dry at room temperature for approximately 30 min. Neutral Detergent Solution. The spring onion samples (1 kg) at 12 DAT were dipped at stagnant tap water containing 1% neutral detergent for 1 min. Afterward, they were washed with running tap water (the flow rate of the water was 1 L/10 s) for 30 s 2 times. Then, the spring onion was air-dried under room conditions. Drying Process. Spring onion samples from a treated field were dried in the oven at 80 °C for 24 h or freeze-dried in the freeze dryer for 3 days. The compensated residue level (CRL) was expressed as fresh sample weight based on using the weight loss during the dry process. Weight reduction ratio (WRR) was calculated by dividing the weight before dry by the weight after dry. The CRL and removal rate was derived from the following formulation:

Table 2. Recovery and MLOQ for Etofenprox in Spring Onion

a b

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recovery ± CVa

MLOQ (mg/kg)b

0.5 1 10

97.0 ± 7.9 92.0 ± 6.3 107.7 ± 4.3

0.05

Coefficient of variation = standard deviation/average × 100. Method limit of quantification.

the coefficient of variation (CV) less than 7.9%. According to the methods and criterion of pesticide registration tests, a typical recovery range should be from 75 to 120%, and the CV (standard deviation/average × 100) should be below 20%.14 The HPLC chromatograms of the spring onion sample were shown in Figure 2. The retention time of etofenprox was 17.4 min, and no chromatographic interferences in the untreated sample of spring onion were observed. Thus, the developed method is applicable to analysis of the etofenprox residue in spring onion. Biological Half-Lives of Etofenprox on Spring Onion. Under field conditions, various environmental conditions, such as temperature, moisture, and microbial activity, result in different degradation kinetics during the experimental period.15 Decline of the pesticide residue during crop cultivation may be attributed primarily to physical chemistry characteristics of the pesticide as well as conditions of the cultivation, weathering, heat decomposition, methods for application, pre-harvest interval, or other complex conditions.16−18 The etofenprox residue on the spring onion on the day of application under a standard application rate was 9.0 mg/kg and decreased to 3.1 mg/kg after 14 days after final treatment, while the initial concentration of etofenprox with 2 times application with a 7 day interval was 10.6 mg/kg and decreased to 2.7 mg/kg after the same period (Table 3). The MRL of etofenprox was set as 2.0 mg/kg in spring onion in Korea, but the residue at 14 DAT was higher than the MRL. To find the method to reduce the residue below the MRL, we conducted a removal experiment by washing and drying. The biological half-life of etofenprox at 1 time application determined from the first-order kinetics was 9.5 days, and degradations could be described by following equation C = 8.8197e−0.073t, with a correlation coefficient R2 of 0.8792. At 2 times application, the half-life was 7.9 days and degradations

weight before dry (g) WRR = weight after dry (g)

CRL (mg/kg) =

fortified level (mg/kg)

residue after dry (mg/kg) WRR

⎛ ⎞ CRL removal rate (%) = ⎜1 − ⎟ × 100 residue before dry ⎠ ⎝

RESULTS AND DISCUSSION Validation of the Analytical Method. Method validation is a set of procedures to evaluate the performance characteristics, such as recovery, reproducibility, linearity, range of calibration, limit of detection (LOD), and quantitation of a method for specific analyte and sample types.10 Quantification was accomplished by preparation of an external standard calibration curve after the dilution of the stock standard solution with acetonitrile. The calibration curve of etofenprox was linear from 0.25 to 50 mg/kg, covering the whole range of concentrations in the samples. The regression equation was y = 20.60396x + 9.97170, with the correlation coefficient (R2) of 0.9995. Instrumental LOD and limit of quantitation (LOQ) express the sensitivity of analytical instruments.11,12 On the basis of the analysis of several concentrations, 1.0 and 2.5 ng were determined as the LOD and LOQ, respectively, which were satisfactory for sensitive analysis of etofenprox residue. The method limit of quantitation (MLOQ) is not an instrumental LOQ but, instead, is a practical LOQ for the total analytical method. It is calculated using LOQ, injection volume, final solution volume, and sample weight in the analytical method.13 6677

DOI: 10.1021/acs.jafc.5b02345 J. Agric. Food Chem. 2015, 63, 6675−6680

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Journal of Agricultural and Food Chemistry

Table 3. Decline of Etofenprox Residues (mg/kg) on Spring Onion after 1 and 2 Times Application (n = 3) residue level (mg/kg) application

DATa

1

0 1 2 4 6 8 10 12 14 0 1 2 4 6 8 10 12 14

2

a

average ± SDb

replicate 8.8 9.0 8.9 5.4 4.9 4.2 4.6 4.7 3.1 10.6 9.3 8.8 7.4 5.5 5.2 4.7 4.0 2.7

9.1 8.9 9.0 5.6 4.8 4.9 4.4 4.5 3.2 10.9 10 8.5 7.7 5.4 4.8 4.6 4.1 2.7

9.0 9.0 8.8 5.7 4.6 4 4.3 4.1 2.9 10.2 9.7 8.1 7.5 5.7 4.7 5.1 4.4 2.7

9.0 9.0 8.9 5.6 4.8 4.4 4.4 4.4 3.1 10.6 9.7 8.5 7.5 5.5 4.9 4.8 4.2 2.7

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.1 0.1 0.1 0.1 0.1 0.4 0.1 0.3 0.1 0.3 0.4 0.4 0.1 0.2 0.3 0.3 0.2 0.0

Days after final treatment. bStandard deviation.

Table 4. Biological Half-Lives of Etofenprox on Spring Onion 1 and 2 Times Application application

application dose

equation

R2

half-life (day)

1 2

20 mL/20 L 20 mL/20 L × 2

C = 8.8197e−0.073t C = 10.368e−0.088t

0.8792 0.9611

9.5 7.9

experiment with Chinese cabbage ranged from 16.47 to 39.26 °C; this was higher than the greenhouse temperature of spring onion, which was 12.5−20.8 °C. Because a higher temperature accelerates the degradation of etofenprox, the half-lives of Chinese cabbage were less than those of spring onion.20 Photodegradation half-lives of etofenprox on the flooded soil surface and the air-dried surface under 300 nm ultraviolet (UV) light were 3.0 and 19 days, respectively.21 Etofenprox degradation occurred relatively quickly on a glass surface with the half-life of 0.23 days compared to both flooded and airdried soil layers.21 From the microbial degradation experiment, the overall anaerobic half-lives ranged from 49.1 to 100 days at 22 °C compared to 27 days at 40 °C, whereas they were 27.5 days at 22 °C and 10−26.5 days at 40 °C under aerobic conditions. Etofenprox was stable for 56 days of the incubation period in the sterilized control soil.22 Removal Efficiency of Etofenprox by Washing. Washing is generally the first step in various types of processes of food commodities in combination with cooking, drying, peeling, and juicing, to allow for effective decontamination from pesticide.9 The average residue of etofenprox on spring onion at 12 days after treatment was 4.44 mg/kg. The washing of treated spring onion in the water bath, running tap water, and 1% neutral detergent solution reduced the residue level to 3.48, 2.49, and 3.18 mg/kg, respectively, with a corresponding removal percentage of 21.6, 43.9, and 28.5, respectively (Figure 3). The running tap water washing was more effective than tap water bath washing in removal of etofenprox in spring onion. The water solubility of etofenprox is very low and non-

Figure 2. HPLC chromatograms of etofenprox in spring onion extract (A, untreated; B, 1.0 mg/kg level fortified; and C, 12 DAT sample of one time application).

could be described by following equation C = 10.368e−0.088t, with R2 = 0.9611 (Table 4). The biological half-lives of etofenprox in Chinese cabbage under the greenhouse condition were 3.2 and 2.7 days at the recommended rate and the double rate of recommendation, respectively.19 The half-lives of etofenprox in green onion are longer than in Chinese cabbage. The weight and growth rate of Chinese cabbage were higher than those of spring onion. Spring onion had a more specific surface area per unit weight than Chinese cabbage, which made a higher deposition of pesticide on the surface, and a slow growth rate resulted in slower dissipation of residues. The greenhouse temperature during the 6678

DOI: 10.1021/acs.jafc.5b02345 J. Agric. Food Chem. 2015, 63, 6675−6680

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Journal of Agricultural and Food Chemistry

than freeze drying in removal of etofenprox in spring onion, because the pesticide degraded by heat.36 Drying has been reported to reduce the pesticide residues considerably. Sun drying of raisin decreased the dimethoate residue by 81%, while oven drying after washing lead to a 73% decline in the residue. The decrease in dimethoate was attributed to heat, which could cause evaporation and degradation.36 For sunlight drying in raisin processing, the residue level of vinclozolin and dimethoate was reduced to one-third and one-fifth of the fresh fruits, respectively. While the oven drying after washing caused residue decreases for iprodione and procdymidone of 57 and 47%, respectively. However, oven drying increased the phosalone residue level compared to sunlight drying, which could be attributed to photodegradation.36 Drying of grape leads to 64.2−71.9% losses of methamidophos possibly because of evaporation of the pesticide during the process.37 In conclusion, the biological half-lives of etofenprox in spring onion were found to be 9.5 and 7.9 days, at the single or double application rates and most residues of etofenpox in spring onion could be removed by oven drying after washing with running tap water.

Figure 3. Removal efficiency of etofenprox on spring onion by different washing and drying processes (n = 3).

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systemic. Most etofenprox will be deposited on the surface of the crop, and loosely attached residues could be effectively removed by a gentle running stream of water, which also results in a low removal rate of detergent solution in a bath. Running water was effective to remove diazinon and procymidone residues in cucumber and tomatoes, respectively.23,24 Washing is the most common process, which is the preliminary step in both household and commercial preparations. Loosely held residues of several pesticides are removed with reasonable efficiency by various types of washing processes in many agricultural commodities, such as green bean, bitter gourd, rice, eggplant, mango, apple, peach, and tomatoes.25−34 In this study, the running water washing is the most effective to remove etofenpox by 43.9%, but another paper reported that tap water was least effective in reducing the pesticide residues and removed them by only 10−12%.35 Washing with water and/or detergent solution was necessary to decrease the intake of the pesticide residue. The acidic detergent solution was more effective in the removal of organochlorine under investigation than alkaline and neutral solutions.35 Removal Efficiency of Etofenprox by Drying. Drying is the oldest and quite a simple method of preserving food compared to other methods. Several methods of drying by sun or in an oven or a freeze dryer can be used. The residue of etofenprox on spring onion 12 days after treatment was 4.44 mg/kg on average. The residue level increased to 12.04 and 30.29 mg/kg after heat dry and freeze dry, respectively. The residue could be concentrated by mass reduction during the dry process because of water evaporation. The CRL calculated was 0.64 by heat dry, while it was 1.48 mg/kg by freeze dry, corresponding to a removal rate of 85.5 and 66.6%, respectively (Figure 3 and Table 5). The heating drying was more effective

*Telephone: +82-31-670-5083. Fax: 82-31-670-5089. E-mail: [email protected]. Author Contributions †

Kyu-Won Hwang and Woo-Suk Bang contributed equally to this work. Funding

This work was supported by the 2013(213A380059) Yeungnam University Research Grant. Notes

The authors declare no competing financial interest.

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after drying residue (mg/kg) weight reduction ratio compensated residue (mg/kg) removal rate (%)

4.4 ± 0.2

heat 12.0 18.7 0.6 85.5

± ± ± ±

freeze 2.5 0.2 0.1 3.0

30.1 20.4 1.5 66.6

± ± ± ±

REFERENCES

(1) Krol, W. J.; Arsenault, T. L.; Pylypiw, H. M.; Incorvia Mattina, M. J. Reduction of pesticide residues on produce by rinsing. J. Agric. Food Chem. 2000, 48, 4666−4670. (2) Clark, J. M.; Symington, S. B. Advances in the mode of action of pyrethroids. Top. Curr. Chem. 2012, 314, 48−72. (3) Jia, G.; Bi, C.; Wang, Q.; Qiu, J.; Zhou, W.; Zhou, Z. Determination of etofenprox in environmental samples by HPLC after anionic surfactant micelle-mediated extraction (coacervation extraction). Anal. Bioanal. Chem. 2006, 384, 1423−1427. (4) Tomlin, C. D. C. The Pesticide Manual, 15th ed.; British Crop Protection Council: Hamlshire, U.K., 2009; pp 454−455. (5) Becker, N.; Petric, D.; Zgomba, M.; Boase, C. Mosquito and Their Control, 2nd ed.; Springer: New York, 2010; p 463. (6) Korean Crop Protection Association (KCPA). Pesticide Handbook; KCPA: Seoul, Korea, 2014; pp 606−609. (7) Amagase, H.; Petesh, B. L.; Matsuura, H. Intake of garlic and its bioactive components. J. Nutr. 2001, 131, 955S−962S. (8) Liu, S.; He, H.; Feng, G.; Chen, Q. Effect of nitrogen and sulfur interaction on growth and pungency of different pseudostem types of Chinese spring onion (Allium f istulosum L.). Sci. Hortic. 2009, 121, 12−18. (9) Kaushik, G.; Satya, S.; Naik, S. N. Food processing a tool to pesticide residue dissipation − a review. Food Res. Int. 2009, 42, 26− 40. (10) Lee, H.; Kim, E.; Moon, J. K.; Zhu, Y. Z.; Do, J. A.; Oh, J. H.; Kwon, K. S.; Lee, Y. D.; Kim, J. H. Establishment of analytical method for cyazofamid residue in apple, mandarin, Korean cabbage, green pepper, potato and soybean. J. Korean Soc. Appl. Biol. Chem. 2012, 55, 241−247.

Table 5. Pesticide Residue and Removal Rate from Spring Onion Dried in an Oven and a Freeze Dryer (n = 3)

before drying

AUTHOR INFORMATION

Corresponding Author

3.1 0.1 0.2 3.4 6679

DOI: 10.1021/acs.jafc.5b02345 J. Agric. Food Chem. 2015, 63, 6675−6680

Article

Journal of Agricultural and Food Chemistry (11) Fong, W. G.; Moye, H. A.; Seiber, J. N.; Toth, J. P. Pesticide Residues in Foods: Methods, Technologies, and Regulations; John Wiley & Sons, Inc.: New York, 1999. (12) Miller, J. M. Chromatography: Concepts and Contrasts; Wiley: Hoboken, NJ, 2005. (13) Lee, J. H.; Park, H. W.; Keum, Y. S.; Kwon, C. H.; Lee, Y. D.; Kim, J. H. Dissipation pattern of boscalid in cucumber under greenhouse condition. Korean J. Pest. Sci. 2008, 12, 67−73. (14) Lee, Y. D. Practical Guide for Food Code Pesticide Residue Analysis; Korea Food and Drug Administration: Osong, Korea, 2013. (15) Gupta, S.; Gajbhiye, V. T.; Gupta, R. K. Soil dissipation and leaching behavior of a neonicotinoid insecticide thiamethoxam. Bull. Environ. Contam. Toxicol. 2008, 80, 431−437. (16) Kanazawa, J. Environmental Sciences of Pesticide; Cooperative Publication: Japan, 1992; pp 55−56. (17) Walash, M. I.; Metwally, M. E.; Hefnawy, M. M. Spectrophotometric determination of maneb, zineb, and their decomposition products in some vegetables and its application to kinetic studies after greenhouse treatment. Food Chem. 1993, 47, 411− 416. (18) Valverde-Garcia, A. G. P. E.; Aguilera-Del Real, A.; UreñaAmate, M. D.; Camacho-Ferre, F. Determination and degradation study of chlorothalolnil residues in cucumber, peppers, and cherry tomatoes. Anal. Chim. Acta 1993, 276, 15−23. (19) Lee, E. Y.; Noh, H. H.; Park, Y. S.; Kanf, K. W.; Kim, J. K.; Jin, Y. D.; Yun, S. S.; Jin, C. W.; Han, S. K.; Kyung, K. S. Residual characteristics of etofenprox and methoxyfenozide in Chinese cabbage. Korean J. Pestic. Sci. 2009, 13, 13−20. (20) European Food Safety Authority (EFSA). Opinion on a request from EFSA related to the default Q10 value used to describe the temperature effect on transformation rates of pesticide in soil. EFSA J. 2007, 62, 1−32. (21) Vasquez, M.; Cahill, T.; Tjeerdema, R. Soil and glass surface photodegradation of etofenprox under simulated California rice growing condition. J. Agric. Food Chem. 2011, 59, 7874−7881. (22) Vasquez, M.; Holstege, D. M.; Tjeerdema, R. Aerobic versus anaerobic microbial degradation of etofenprox in a California rice field soil. J. Agric. Food Chem. 2011, 59, 2486−2492. (23) Cengiz, M. F.; Certel, M.; Karakas, B.; Gocmen, H. Residue contents of DDVP(Dichlorvos) and diazinon applied on cucumbers grown in greenhouses and their reduction by duration of a pre-harvest interval and post-harvest culinary applications. Food Chem. 2006, 98, 127−135. (24) Cengiz, M. F.; Certel, M.; Karakas, B.; Gocmen, H. Residue contents of captan and procymidone applied on tomatoes grown in greenhouses and their reduction by duration of a pre-harvest interval and post-harvest culinary applications. Food Chem. 2007, 100, 1611− 1619. (25) Cabras, P.; Angioni, A.; Garau, V. L.; Melis, M.; Pirisi, F. M.; Karim, M.; Minelli, E. V. Persistence of insecticide residues in olives and olive oil. J. Agric. Food Chem. 1997, 45, 2244−2247. (26) Street, J. C. Methods of removal of pesticide residues. Can. Med. Assoc. J. 1969, 100, 154−160. (27) Marshall, W. D. Preprocessing oxidative washes with alkaline hypochlorite to remove ethylenebis(dithiocarbamate) fungicide residues from tomatoes and green beans. J. Agric. Food Chem. 1982, 30, 649−652. (28) Nath, G.; Agnihotri, S. Removal of endosulfan from bitter gourds by home processing. Pesticides 1984, 18, 13−15. (29) Lee, S. R.; Mourer, C. R.; Shibamoto, T. Analysis before and after cooking processes of a trace chlorpyrifos spiked in polished rice. J. Agric. Food Chem. 1991, 39, 906−908. (30) Kumar, U.; Agarwal, H. C. Degradation of dithane M-45 residues in brinjals during cooking. Bull. Environ. Contam. Toxicol. 1991, 47, 725−731. (31) Awasthi, M. D. Decontamination of insecticide residues on mango by washing and peeling. J. Food Sci. Technol. 1993, 30, 132− 133.

(32) Mergnat, T.; Fritsch, P.; Saint-Joly, C.; Truchot, E.; SaintBlanquat, G. Reduction in phosalone residue levels during industrial dehydration of apples. Food Addit. Contam. 1995, 12, 759−767. (33) Ong, K. C.; Cash, J. N.; Zabik, M.; Siddiq, M.; Jones, A. L. Chlorine and ozone washes for pesticide removal from apples and processed apple sauce. Food Chem. 1996, 55, 153−160. (34) Abou-Arab, A. A. K. Behavior of pesticides in tomatoes during commercial and home preparation. Food Chem. 1999, 65, 509−514. (35) Zohair, A. Behaviour of some organophophorus and organochlorine pesticides in potatoes during soaking in different solutions. Food Chem. Toxicol. 2001, 39, 751−755. (36) Cabras, P.; Angioni, A.; Garau, V. L.; Melis, M.; Pirisi, F. M.; Cabitza, F.; Pala, M. Pesticide Residues in raisin processing. J. Agric. Food Chem. 1998, 46, 2309−2311. (37) Athanasopoulos, P. E.; Pappas, C.; Kyriakidis, N. V.; Thanos, A. Degradation of methamidophos on soultanian grapes on the vines and during refrigerated storage. Food Chem. 2005, 91, 235−240.

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DOI: 10.1021/acs.jafc.5b02345 J. Agric. Food Chem. 2015, 63, 6675−6680