• Journal of Food Hygiene and Safety
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• v.21 no.2
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• pp.52-59
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• 2006

This survey was conducted to monitor the current status of pesticide residues in imported agricultural products circulated in Gwangju, 2005. A total of 108 samples was analyzed by multiresidue method. Of these samples, 32 were citrus fruits, 60 were tropical fruits and grapes, and 16 were vagetables. The origin was Philippine for 39 samples, U.S.A. for 36, China for 12, New Zealand for 11, Chile for 6, etc. The overall rate of detections was 30.6% and no samples had violative residues. Of citrus fruits,20 samples (62.5%) had residues and the residues were thiabendazole, imazalil, chlorpyrifos, etc. Of tropical fruits and grapes, 13 samples (12.0%) had residues and the residues were azoxystrobin, chlorpyrifos, carbendazim, captan, etc. 16 of vagetables had no detectable pesticide residues. Thiabendazole (71% in oranges and 56% in grapefruits) and imazalil (50% in oranges) were found in citrus fruits, which were frequently used as post-harvest pesticides. And azoxystrobin which is one of strobilurin fungicides, was often detected in mango, tropical fruit(27%).

• Journal of environmental and Sanitary engineering
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• v.6 no.2
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• pp.89-108
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• 1991

Organophosphorus pesticide residues such as Diazinon, Fenitrothion and EPN in apple and effect of storage peeling and washing on removal of the residues from apple soaked in 3 kinds of pesticides solutions for 20 seconds were studed with gas chromatography-nitrogen phosphorus detecter(GC-NPD). Result obtained are as follows : 1) Average concentrations of DiaEinon, Fenitrothion, and EPN detected in apple of control group were 0.022, 0.007 and 0.008 ppm respectively. 2) Decreasing rates of Diazinon on 7 th, 14 th, 21 st, 28 th, and 35 th day after soaking apple on the pesticide solution were 41.3% , 68.6% , 87.0%, 96.9% and 99.5% respectively. In case of Fenitrothion were 46.9%, 66.3%, 84.9%, 93.2% and 97.3% and EPN were 45.7 %, 76.2%, 85.4%, 95.7% and 99.4% respectively. 3) The removal rate of Diazinon, Fenitrothion and EPN by washing with water alone were 93.7%, 70.6% and 51.5% respectively, and 97.1% , 78.4% ailed 76.5% by washing with 0.2% detergent solution respectively. The results obtained in this study have show that 3 kinds of pesticides detected in app- les were below the Korean standard for residual pesticides and pesticides contaminated in apples were decreased in considerable degree by washing with water and 2% detergent solution and removed almost completely after storage for 35 days (5 weeks). Therefore, it would be concluded that washing and peeling will be the most effective way for safely because more than 90% of pesticide exist in peel.

• The Korean Journal of Pesticide Science
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• v.6 no.4
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• pp.293-299
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• 2002

This experiment was conducted to elucidate the effects of fruit bagging on the amounts of pesticide residues on/in pears with two pesticides, chlorpyrifos 25% WP, and penconazole 5% WP, and two pear cultivars, Niitaka and Hwangeum-bae. Residues of chlorpyrifos and penconazole in bagged pears were only $0.4{\sim}27%$ of those in non-bagged one. Residues of both pesticides in bagged and non-bagged pears were steeply reduced in the field but slowly reduced during storage. Residues of chlorpyrifos were more in the peel than in the flesh, while penconazole in bagged pear was evenly distributed in the peel and flesh. Chlorpyrifos was evenly distributed in outer bag and inner bag irrespective of bag materials, while most of penconazole was found in outer bag rather than in inner bag. To produce safer pear from pesticide residues, removal of bag before storage is recommended.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.118-123
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• 2018

The objective of this study was to develop a sensitive method for the identification and determination of nitrovin in fishery products by using a solid-phase extraction (SPE), as performed with a liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted with a mixture of acetonitrile and water, and were then defatted with acetonitrile saturated hexane, after which further clean-up was accomplished with SPE on the hydrophilic-lipophilic balance (HLB) cartridges. The analytes were subsequently ionized in the positive mode of an electrospray ionization (ESI), and where thereby detected in a process of multiple reaction monitoring (MRM). The linearity (expressed as correlation coefficients) of the matrix calibration curves was > 0.985. The limit of the quantification for the nitrovin was measured at 0.001 mg/kg. The accuracy (expressed as average recovery) was noted between 72.1 and 122%. The precision (expressed as coefficient variation) was noted from 2.9 to 16.9%. According to the CODEX CAC/GL-71 guideline accuracy, precision, linearity, and limit of detection were determined in three matrices (which were flatfish, eel and shrimp). The proposed method was suitable for analyzing the associated nitrovin residues. This application and result can also be a factor to contribute to the non-detection drugs management in fishery products.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.318-327
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• 2015

BACKGROUND: Trinexapac-ethyl is a plant growth regulator (PGR) that inhibits the biosynthesis of plant growth hormone (gibberellin). It is used for the prevention of lodging, increasing yields of cereals, and reducing mowing of turf. The experiment was conducted to establish a determination method for trinexapac-ethyl and its metabolites trinexapac in agricultural products using LC-MS/MS.METHODS AND RESULTS: Trinexapac-ethyl and trinexapac were extracted from agricultural products with methanol/ distilled water and the extract was partitioned with dichloromethane and then detected by LC-MS/MS. Limit of detection(LOD) was 0.003 mg/kg and limit of quantification(LOQ) was 0.01 mg/kg, respectively. Matrix matched calibration curves were linear over the calibration ranges (0.01-1.0 mg/L) for all the analytes into blank extract withr²> 0.997. For validation purposes, recovery studies were carried out at three different concentration levels (LOQ, 10LOQ, 50LOQ,n=5). Recoveries of trinexapacethyl and trinexapac were within the range of 73.6-106.9%, 72.7-99.2%, respectively. The relative standard deviations (RSDs) were less than 9.0%. All values were consistent with the criteria ranges requested in the CODEX guideline(CAC/GL 40, 2003).CONCLUSION: The proposed analytical method was accurate, effective and sensitive for trinexapac-ethyl and trinexapac determination and it can be used to as an official method in Korea.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.131-139
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• 2023

In this study, we investigated pesticide residue levels in 535 domestically distributed agricultural products in South Korea using multi-residue analysis. Agricultural products from 13 regions, including Seoul, were pretreated using QuEChERS and d-SPE, and subsequently analyzed using LC-MS/MS and GC-MS/MS. Residual pesticides were detected in 288 (53.8%) out of the 535 samples, including 40 of apples, 40 of peppers, 33 of mandarins, 31 of peaches, and 144 other commodities. Furthermore, one sample of Korean cabbage exceeded the permitted maximum residue limit (MRL), diniconazole (0.18 mg/kg), detected at about twice the MRL. In total, 91 types of residual pesticides were detected, including fungicides (42), insecticides (48), and a nematicide. The most frequently detected pesticides were dinotefuran (91), carbendazim (75), tebuconazole (61), and pyraclostrobin (59). Our results showed that continuous monitoring of agricultural products is necessary.

• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.531-536
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• 2013

We developed a simple, sensitive, and specific analytical method for prometryn using gas chromatography-mass spectrometry (GC-MS). Prometryn is a selective herbicide used for the control of annual grasses and broadleaf weeds in cotton and celery crops. On the basis of high specificity, sensitivity, and reproducibility, combined with simple analytical operation, we propose that our newly developed method is suitable for use as a Ministry of Food and Drug Safety (MFDS, Korea) official method in the routine analysis of individual pesticide residues. Further, the method is applicable in clams. The separation condition for GC-MS was optimized by using a DB-5MS capillary column ($30m{\times}0.25mm$, 0.25 ${\mu}m$) with helium as the carrier gas, at a flow rate of 0.9 mL/min. We achieved high linearity over the concentration range 0.02-0.5 mg/L (correlation coefficient, $r^2$ >0.998). Our method is specific and sensitive, and has a quantitation limit of 0.04 mg/kg. The average recovery in clams ranged from 84.0% to 98.0%. The reproducibility of measurements expressed as the coefficient of variation (CV%) ranged from 3.0% to 7.1%. Our analytical procedure showed high accuracy and acceptable sensitivity regarding the analytical requirements for prometryn in fishery products. Finally, we successfully applied our method to the determination of residue levels in fishery products, and showed that none of the analyzed samples contained detectable amounts of residues.

• Analytical Science and Technology
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• v.29 no.2
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• pp.94-103
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• 2016

An analytical method was developed to determine the amount of spinetoram (spinetoram J and spinetoram L) in livestock samples. The spinetoram was extracted with acetonitrile and purified through a primary secondary amine (PSA) sorbent. The spinetoram residues were then quantified and confirmed using a liquid chromatography–tandem mass spectrometer (LC-MS/MS) in the positive ion mode using multiple reactions monitoring (MRM). Matrix-matched calibration curves were linear over the calibration ranges (0.005-0.5 mg/kg) into a blank extract with r² > 0.994. The limits of detection and quantification were 0.002 and 0.01 mg/kg, respectively. The recovery results of spinetram ranged between 81.9-106.4% at different concentration levels (LOQ, 10LOQ, 50LOQ, n=5) with relative standard deviations (RSDs) less than 10%. All values were consistent with the criteria ranges requested in the Codex guidelines (CAC/GL40, 2003). An interlaboratory study was conducted to validate the method. The proposed analytical method proved to be accurate, effective, and sensitive for spinetoram determination. The method will be used as an official analytical method in Korea.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.323-334
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• 2008

This experiment was carried out to analyze for pesticide residues in 17 different types of the special of geographical indication. We purchased 3 cereal grains, nuts and seeds, 3 fruits, 8 vegetables, mushrooms and other plants (Korean medicines) mainly at the agricultural cooperative's joints markets. Total 209 pesticides including multi-analysed pesticides (204) and single-analysed pesticides (5 ; acephate, methamidophos, monocrotophos, omethoate, vamidothion) were analysed with a GC/MS/MS, an HPLC/UVD (PDA) and a GC/FPD. No. 83 method and single-analysed method (Screening of multi-pesticide residue in the special products of geographical indication) of Korea Food Code was selected for validation in recovery and interferences of matrice. The results were as follows: among the selected 17 the special products, the residual pesticides were detected in 8 types of the special products (40 in 302 samples, detection ratio; 13.2%). All of the samples were not detected over MRLs, but tebuconazole, procymidone and isoprothioran were detected with considerable high frequency. These results could be used as KFDA official methods for the analysis of pesticide residues in foods and reference data will be provided to the related institutions.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.357-362
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• 2008

In order to survey the residual characteristics of pesticides and assess their safeties in the agricultural products from markets, the agricultural products were purchased from the wholesale and traditional markets in Cheongju and Jeonju and analyzed the pesticide residues in them. No pesticide residues were found in samples from Cheongju, whereas, in case of samples collected from Jeonju, 3 pesticides including chlorothalonil were detected from 5 samples such as eggplant from wholesale market and 3 pesticides including azoxystrobin were found in tomato and grape from traditional market. Pesticide residues were detected from 10.9% of the total samples and detection levels were less than their maximum residue levels. Their estimated daily intakes ranged from 0.00102 to 0.03616% of their acceptable daily intakes, representing residue levels of the pesticides detected were evaluated to be safe.