Dae Hyun Cho

Multiresidue Analysis of Pesticides in Agricultural Products by a Liquid Chromatography/Tandem Mass Spectrometry Based Method

A sensitive and specific liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for the determination of 56 residual pesticides from commercial crops. For a validation of the method, the recoveries, linearities, limits of detection (LOD), and limits of quantitation (LOQ) of the 56 pesticides were investigated. The linearities, LOD, and mean recoveries of the pesticides ranged 0.9686–0.9999, 0.00–11.54 μg/kg, and 65–82%, respectively. This method was evaluated by its application to monitor 345 agricultural products collected from 9 provinces in Korea 2011. Fifteen pesticides were detected from 39 samples and 2 or more residual pesticides were found in 7 samples. However, none of the compounds were observed above the corresponding maximum residue level. The results reflect that the detected pesticide residues were in a safe range and that residual pesticides in the agricultural products in Korea were properly controlled.

Evaluation of Residual Pesticides in Commercial Agricultural Products Using LC-MS/MS in Korea

Pesticide residues in agricultural products in Korea were evaluated to create a data base to inform food policy. Pesticide residues were investigated in 17 commodities collected from 9 provinces in 2012. Our analytical method of multiresidue analysis, involved the analysis of individual recovery, linearity, limit of detection, and limit of quantitation of 60 pesticides in six matrices. The pesticides, including acetamiprid and forchlorofenuron, were evaluated in 358 agricultural samples by liquid chromatography/tandem mass spectrometry. Twenty three pesticides were detected from 67 samples. The results showed that the ratio of estimated daily intake to acceptable daily intake was 0.00009-0.0861% by the intake assessment, which means that residual pesticides in agricultural products in Korea are properly controlled.Pesticide residues in agricultural products in Korea were evaluated to create a data base to inform food policy. Pesticide residues were investigated in 17 commodities collected from 9 provinces in 2012. Our analytical method of multiresidue analysis, involved the analysis of individual recovery, linearity, limit of detection, and limit of quantitation of 60 pesticides in six matrices. The pesticides, including acetamiprid and forchlorofenuron, were evaluated in 358 agricultural samples by liquid chromatography/tandem mass spectrometry. Twenty three pesticides were detected from 67 samples. The results showed that the ratio of estimated daily intake to acceptable daily intake was 0.00009-0.0861% by the intake assessment, which means that residual pesticides in agricultural products in Korea are properly controlled.

Residue analysis of penicillines in livestock and marine products

Penicillins belong to the -lactam class of antibiotics, and are frequently used in human and veterinary medicine. Despite the positive effects of these drugs, improper use of penicillins poses a potential health risk to consumers. This study has been undertaken to determinate multi-residues of penicillins, including amoxicillin, ampicillin, oxacillin, bezylpenicillin, cloxacillin, dicloxacillin, and nafcillin, using liquid chromatographic tandem mass spectrometer (LC-MS/MS). The developed method was validated for specificity, precision, recovery, and linearity in livestock and marine products. The analytes were extracted with 80% acetonitrile and clean-up by a single reversed-phase solid-phase extraction step. Six penicillins presented recoveries higher than 76% with the exception of Amoxicillin. Relative standard deviations (RSDs) were not more than 10%. The method was applied to 225 real samples. Benzylpenicillin was detected in 12 livestock products and 7 marine products. Amoxicillin, ampicillin, cloxacilllin, dicloxacillin, nafcillin and oxacillin were not detected. The detected levels were 0.001~0.009 mg/kg in livestock products excluding eggs and milk. In marine products, the detected levels were under 0.03 mg/kg. They were under the MRL levels. As monitoring results, it is identified to be safe but it is considered that safety management of antibiotics should continue by monitoring.