• Journal of Food Hygiene and Safety
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• v.11 no.2
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• pp.99-105
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• 1996

An attempt was made to determine the residual distribution of organochlorine and organophosphorus pesticides in the various kinds of Korean tea which were purchased form the maket. The organochlorine pesticides investigated in this study were BHC, DDT and dicofol and the organophoshorus pesticides were diazinon, EPN, fenitrothion and parathion. The pesticide residues were determined by GC-ECD and BHC was detected in all the samples and it's level were ranged from 0.00064 po 0.05995 ppm and it's average was 0.00682 ppm and DDT, dicofol and organophosphorus pesticides were not detected in all samples. The organophophorus pesticides were detected(0.0035∼0.0983 ppm) in raw materials but were not in the manufactured material and it is considered that the largely components of the pesticides is removed by drying and high temperature while the tea was manufactured. The recovery tests of the pesticides gave satisfactory results showing an average yield of 97.6% with organochlorine pesticides and 92.5% with organophoshorus pesticides and the detection limits level were 0.00008 ppm to 0.0010 ppm.

• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.11-17
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• 2000

Optimum parameters were investigated for the simultanious analysis of 24 pesticide residuces using gas-liquid chromatography with electron capture detection. Electronic pressure control(EPC) on column enhanced resolution of 24 analyzes. Using DB-17, SPB-608, and Ultra-2 capillary column without EPC incomplete separation was observed in some pairs of pesticides. When EPC function was adopted, no severe overlapping was observed on SPB-608 column in every pesticides except vinclozolin/acetochlor pair. Total running time was 45 min, much shorter than $69{\sim}81$ min when used without EPC. Limit of determination of each analyze ranged $0.1{\sim}12.9$ ng/mL.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.172-180
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• 2016

This study was conducted to evaluate the relations between the exposure level of organophosphates (OPs) pesticide and application factors among rural farmers. The urinary dialkylphosphates, metabolites of organophosphorus pesticides, including DMP, DEP, DMTP and DETP were analyzed by GC/MSD and GC/MS/MS. The DMP and DMTP were detected more in the use of a speed sprayer without cap than with a capped one. Also, the less farmers wore the personal protective equipment (PPE), the more these were detected. The amount of organophosphorus exposure was the highest in the use of a power sprayer. However, it was low when a farmer applied pesticides with a speed sprayer with cap and wore more PPE. In this study, the detection rate was analyzed by chi-square test, the exposure level of OPs was analyzed by a generalized linear model.

• Journal of Food Hygiene and Safety
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• v.3 no.4
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• pp.193-202
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• 1988

A pesticide monitoring study was undertaken for the strawberry and cucumber samples collected from plastic film houses and additional strawberries from supermarkets located in Seoul city in 1983 to evaluate pesticide residues in these food commodities and also to give basic informations in establishing maximum residue limits. Organophosphorus insecticides were not detected in any cucumber samples except that diazinon found with low residue levels in two strawberry samples. Fungicide procymidone and chlorothalonil were detected with considerable high frequencies in these vegetables while their residue levels were fairly low. Even the maximum residue levels. they were much lower than maximum residue limits established in these vegetables in Environment Administration. Korea. Of the strawberries from supermarkets in Seoul city, procymidone, chlorthalonil and dichlofluanid fungicides were also detected with similar detection frequencies and residue levels to those from the plas tic film houses. By washing the strawberries with tap water, the residues were removed from 38% to 95% of the total residues. Presently, it is considered that pesticide residues in strawberry and cucumber may be no harmfullevels for food commodities.

• Toxicological Research
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• v.26 no.2
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• pp.149-155
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• 2010

The pesticide trichlorfon is readily degraded under experimental conditions to dichlorvos. A method has therefore been developed by which residues of trichlorfon in milk are determined as dichlorvos, using gas chromatography with ${\mu}$-electron capture detection. The identification of dichlorvos was confirmed by mass spectrometry. Milk was extracted with acetonitrile followed by centrifugation, freezing lipid filtration, and partitioning into dichloromethane. The residue after partitioning of dichloromethane was dissolved in ethyl acetate for gas chromatography. Recovery concentration was determined at 0.5, 1.0, and 2.0 of times the maximum permitted residue limits (MRLs) for trichlorfon in milk. The average recoveries (n = 6) ranged from 92.4 to 103.6%. The repeatability of the measurements was expressed as relative standard deviations (RSDs) ranging from 3.6%, to 6.7%. Limit of detection (LOD) and limit of quantification (LOQ) were 3.7 and $11.1{\mu}g/l$, respectively. The accuracy and precision (expressed as RSD) were estimated at concentrations from 25 to $250{\mu}g/l$. The intra- and inter-day accuracy (n = 6) ranged from 89.2% to 91% and 91.3% to 96.3%, respectively. The intra- and inter-day precisions were lower than 8%. The developed method was applied to determine trichlorfon in real samples collected from the seven major cities in the Republic of Korea. No residual trichlorfon was detected in any samples.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1688-1689
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• 2011

A simple and rapid capillary electrophoresis method was developed for the quantitative analysis of common triazine herbicides. Cyclic voltammetry was employed to clarify the detection voltage which showed characteristic irreversible cathodic peaks. For the analysis, the mixture of triazine herbicides was applied in a microfluidic chip to determine the CE-separated peaks. Soil sample extracts were analyzed directly after drying and redissolution with the supporting electrolyte but without other pretreatment. The results were comparable to those obtained by HPLC with UV detection. Therefore, this method can be used in the rapid determination of pesticide/herbicide residues.

• Bulletin of the Korean Chemical Society
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• v.23 no.4
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• pp.599-603
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• 2002

A selective enzyme-linked immunosorbent assay (ELISA) for the insecticide isofenphos was developed. Three different analogues (haptens) of isofenphos were synthesized and were coupled to carrier proteins through the pesticide thiophosphate group t o use as immunogens or coating antigens. Rabbits were immunized with one of the haptens coupled to BSA for production of polyclonal antibodies and the sera were screened against each of the other two haptens coupled to ovalbumin (OVA). Using the sera of highest specificity, an antigen-coated ELISA was developed, which showed an I50 of 96 ng/mL with the detection limit of 2 ng/mL. The antibodies showed negligible cross-reactivity with other organophosphorus pesticides and the phenol metabolite of isofenphos, which makes the developed assay suitable for the selective detection of isofenphos. An antibody-coated ELISA was also developed, which showed an I50 of 580 ng/mL with a detection limit of 70 ng/mL.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.335-349
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• 2011

100 residual pesticides in 1,565 medicinal herbs being on sale in Seoul was analyzed by a simultaneous multiresidue method. The recovery ratio was 71.0~119.7%. The detection rate of pesticide residues was 5.3% and the rate of excess to Maximum Residue Limits (MRLs) was 0.9% of the total samples. The medicinal herbs which had the high detection rate of residual pesticides were Alismatis Rhizoma, Citri Unshii Pericarpium, Lycii Fructus and Zyzyphi Fructus. The medicinal herbs detected pesticide over Maximum Residue Limits (MRLs) were Alismatis Rhizoma (4), Cnidii Rhizomain (4), Chrysanthemi Zawadski Herba (1), Citri Unshii Pericarpium (1), Lycii Radix Cortex (1), Menthae Herba (1), Schisandrae Fructus (1) and Taraxaci Herba (1). The residual pesticides which had the high detection frequency were cypermethrin, chlorpyrifos, phenthoate, endosulfan, isoprothiolane, chlorothalonil and chlorfenapyr. Estimated Daily Intake (EDI) of detected pesticides was compared to Acceptable Daily Intake (ADI) in order to assess risk. Ethoprophos detected in Cnidii Rhizomain showed the highest %ADI, 26.85. And pyraclofos and endosulfan in Cnidii Rhizomain, endosulfan and isoprothiolane in Alismatis Rhizoma and cyprodinil in Taraxaci Herba showed more than 1 %ADI, but others showed below 1 %ADI.

• Journal of Food Hygiene and Safety
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• v.30 no.4
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• pp.366-371
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• 2015

This work was conducted to apply the multi class pesticide multiresidue method for determining the use of hexaconazole in the agricultural products using GC-NPD. The multi class pesticide multiresidue method results were validated for the assay of hexaconazole by using linearity, accuracy, precision, limit of detection and quantitation. The linearity in the concentration ranged from 0.025 to 5.0 mg/L ($R^2$ > 0.999). Lettuce recoveries ranged from 89.42% to 94.15% with relative standard deviations below 7.78%, for spiking levels from 0.04 to 4.0 mg/kg. The limit of detection was 0.04 mg/kg, and the limit of quantitation was 0.11 mg/kg. The intra- and inter-day precisions were 2.42~3.49% and 4.90~7.78%, respectively. We suggested that the multi class pesticide multiresidue method for determining hexaconazole was highly accurate and reproducible, and it will be used as a routine analysis in agricultural products.

• The Korean Journal of Pesticide Science
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• v.13 no.1
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• pp.28-38
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• 2009

An extrapolation of residue data of seven commonly used pesticides namely bifenthrin, chlorothalonil, cypermethrin, diazinon, fenvalerate, phenthoate and procymidone on a total of 22 minor crops has been carried out in an experimental field trial. The pesticides were applied to 11 leafy-, 5 root- and 6 stem-crops grown in the experimental green-house and the crops and plants were randomly collected at 1, 3, 5, 7 days after application. The average recoveries of applied pesticides were ranged from 72.0 to 117.0% in leafy crops, from 81.3 to 105.0% in stem crops and from 70.1 to 108.1% in the root-crops. Limits of detection (LODs) were 0.005-0.1 mg/kg in the leafy crops and 0.001-0.005 mg/kg in both the stem & root crops. Based on the results of residual dissipation pattern and their morphology, all crops were classified into high and low residual groups. The results showed that it might be possible to extrapolate residual data of stem-crops to root-crops within the same group. Crops that have currently no registered pesticide for use, would be possible to use the pesticides which are already been registered for the similar crops.