• Horticultural Science & Technology
• /
• v.34 no.1
• /
• pp.183-194
• /
• 2016

This experiment was conducted to establish an official determination method to measure fluazinam residue in horticultural crops for import and export using GC-ECD/MS. Fluazinam residue was extracted with acetone from fresh samples of four representative horticultural products, the vegetable crops green pepper and kimchi cabbage, and the fruit crops mandarin and apple. The acetone extract was diluted with saline water and n -hexane partitioning was used to recover fluazinam from the aqueous phase. Florisil column chromatography was additionally employed for final purification of the extract. Fluazinam was separated and quantitated by GC with ECD using a DB-17 capillary column. The horticultural crops were fortified with three different concentrations of fluazinam. Mean recoveries ranged from 82.5% to 99.9% in the four crops. The coefficients of variation were less than 10.0%. The quantitative limit of fluazinam detection was $0.004mg{\cdot}kg^{-1}$ in the four crop samples. GC/MS with selected-ion monitoring was also used to confirm the suspected residue. This analytical method was reproducible and sensitive enough to measure the residue of fluazinam in horticultural commodities for import and export.

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

• Journal of Food Hygiene and Safety
• /
• v.37 no.3
• /
• pp.136-142
• /
• 2022

The research aims to develop a rapid and easy analytical method for methoprene using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A simple, highly sensitive, and specific analytical method for the determination of methoprene in livestock products (beef, pork, chicken, milk, eggs, and fat) was developed. Methoprene was effectively extracted with 1% acetic acid in acetonitrile and acetone (1:1), followed by the addition of anhydrous magnesium sulfate (MgSO₄) and anhydrous sodium acetate. Subsequently, the lipids in the livestock sample were extracted by freezing them at -20℃. The extracts were cleaned using MgSO₄, primary secondary amine (PSA), and octadecyl (C₁₈), which were then centrifuged to separate the supernatant. Nitrogen gas was used to evaporate the supernatant, which was then dissolved in methanol. The matrix-matched calibration curves were constructed using 8 levels (1, 2.5, 5, 10, 25, 50, 100, 150 ng/mL) and the coefficient of determination (R²) was above 0.9964. Average recoveries spiked at three levels (0.01, 0.1, and 0.5 mg/kg), and ranged from 79.5-105.1%, with relative standard deviations (RSDs) smaller than 14.2%, as required by the Codex guideline (CODEX CAC/GL 40). This study could be useful for residue safety management in livestock products.

• Food Science of Animal Resources
• /
• v.37 no.6
• /
• pp.847-854
• /
• 2017

A rapid, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of four barbiturates (phenobarbital, pentobarbital, amobarbital and secobarbital) in raw milk. The barbiturates were extracted using liquid-liquid extraction, ultrasonication and centrifugation, and purified on an SPE column. Analytes were separated by HPLC on a CSH C18 column eluted using an acetonitrile-water system with a linear gradient dilution programme, and detected by MS/MS. The recoveries of the barbiturates were 85.0-113.5%, and the intra- and inter-assay RSDs were less than 9.8% and 7.3%, respectively. The limit of detection was 5 ng/mL for all four of the barbiturates. The analytical method exhibited good linearity from 10 to 1000 ng/mL; the correlation coefficient ($r^2$) was greater than 0.9950 for each barbiturate. This method was also applied to the determination of barbiturates in real milk samples and was found to be suitable for the determination of veterinary drug residues in raw milk.

• Journal of Food Hygiene and Safety
• /
• v.33 no.3
• /
• pp.176-184
• /
• 2018

The aim of the present work was to develop simultaneous methods of quantification of carazolol, azaperone, and azaperol residues in livestock and fishery products using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Samples were extracted from beef, pork, chicken, egg, milk and shrimp using acetonitrile (ACN); while flat fish and eel were extracted using 80% ACN. For purification, ACN saturated n-hexane was used to remove fat composition. The standard calibration curves showed good linearity as correlation coefficients; $r^2$ was > 0.99. Average recoveries expressed were within the range of 67.9-105% for samples fortified at three different levels ($0.5{\times}MRL$, $1{\times}MRL$ and $2{\times}MRL$). The correlation coefficient expressed as precision was within the range of 0.55-7.93%. The limit of quantification (LOQ) was 0.0002-0.002 mg/kg. The proposed analytical method showed high accuracy and acceptable sensitivity based on Codex guideline requirements (CAC/GL71-2009). This method can be used to analyze the residue of carazolol, azaperone, and azaperol in livestock and fishery products.

• Journal of Food Hygiene and Safety
• /
• v.35 no.5
• /
• pp.447-451
• /
• 2020

For this study, we conducted a simultaneous multiresidue analysis of veterinary drugs in cultured fishery products in Chungnam Province in 2018. A total of 115 fishery product samples were obtained from fish farms and fishery production sites located in the province. In all, 29 residual veterinary drugs in the samples were analyzed using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. As a result, veterinary drug residues were only detected in a small number of the 106 samples (92.2%), and the detection rate was 7.8% (9 of 115 samples). The amounts were also below maximum residual limit (MRL) for fishery products, although one sample exceeded the MRL allowed by the Ministry of Food and Drug Safety and was detected in loach. The nine residual veterinary drugs were detected in 8 samples: loach, eel, catfish, freshwater bream, flatfish, rockfish and shrimp. The detected veterinary drugs were oxolinic acid, enrofloxacin, ciprofloxacin, sulfadiazine, flumequine and oxytetracycline. The most frequently detected antibiotic was oxolinic acid, and enrofloxacin exceeded the MRL in loach sample. Residues of most veterinary drugs were either not detected or were below the MRL, and while the status of fishery products is seen as safe overall, current surveillance efforts over veterinary drugs should be continued.

• Korean Journal of Veterinary Research
• /
• v.31 no.3
• /
• pp.319-327
• /
• 1991

Gingko biloba is one of the oldest trees on earth. It can be traced 300 million years or more into past. In recent years, this tree has become increasingly popular because of its longevity. Amount of comsumption of Gingko leaves in Korea is increased to produce drugs for blood circulating system's disorder. The workers who work at the company of product drug with Gingko leaves complain pruritus at belt position of west, however toxic substance from extracts of Gingko biloba was carried out to determine what kind of the toxic substance from extract could induce a contact dermatitis by means of histopathological study. Dried leaves of Korean G. biloba were exhaustively extracted with chloroform. The aqueous chloroform residue was extracted with hexane. After evaporation, the hexane extract was passed through a silica gel column chromatography, it was separated into 9 fractions by means of gradient solvent (benzene: acetone/ 98~93 : 2~7%). The 4th and 7th fraction were idendified as bilibol and gingkolic acid by silica gel thin layer chromatography and NMR spectrophotometer. The 4th and 7th fractions of Korean Gingko leaves have an irritant substances which can be induced ear swelling and increased thickness of stratum cornium of rabbit ear exposed with the fractions (3 time/3 day, $100{\mu}l$ of 50mg/ml ethyl alcohol). In the 4th fraction, the substance have induced the surface of ear to swell and mass of unknown cell like inflammatory cell were infiltrated within the stratum corneum, and the 7th fraction have the surface of ear to loss the hairs, and sebaceous gland and follicle of hair were infiltrated with inflammatory cells. and other fractions at all did not induced a certain contact dermatitis and also Deutschen drug of Gingko (named as Gerigeron) have induced the contact dermatitis such as dematitis of Korean Gingko extract.

• Journal of Food Hygiene and Safety
• /
• v.32 no.4
• /
• pp.298-305
• /
• 2017

Benzovindiflupyr is a new pyrazole carboxamide fungicide that inhibits succinate dehydrogenase of mitochondrial respiratory chain. This study was carried out to develop an analytical method for the determination of benzovindiflupyr residues in agricultural commodities using LC-MS/MS. The benzovindiflupyr residues in samples were extracted by using acetonitrile, partitioned with dichloromethane, and then purified with silica solid phase extraction (SPE) cartridge. Correlation coefficient ($r^2$) of benzovindiflupyr standard solution was 0.99 over the calibration ranges ($0.001{\sim}0.5{\mu}g/mL$). Recovery tests were conducted on 5 representative agricultural commodities (mandarin, green pepper, potato, soybean, and hulled rice) to validate the analytical method. The recoveries ranged from 79.3% to 110.0% and then relative standard deviation (RSD) was less than 9.1%. Also the limit of detection (LOD) and limit of quantification (LOQ) were 0.0005 and 0.005 mg/kg, respectively. The recoveries of interlaboratory validation ranged from 83.4% to 117.3% and the coefficient of variation (CV) was 9.0%. All results were followed with Codex guideline (CAC/GL 40) and Ministry of Food and Safety guideline (MFDS, 2016). The proposed new analytical method proved to be accurate, effective, and sensitive for benzovindiflupyr determination and would be used as an official analytical method.

• Korean Journal of Food Science and Technology
• /
• v.46 no.3
• /
• pp.288-294
• /
• 2014

Penicillin and its salts, including the benzatine, procaine, and sodium salts, have been widely used in human and veterinary medicine. Owing to their low toxicity, they currently form the most important group of antibiotics. However, overdose and abuse of these antibiotics may lead to potential risk in human health. Therefore, this study was conducted to validate the analysis method established by the Korea Food Code in 2012 and to monitor the levels of benzylpenicillin residues in products with reference to the maximum residue level (MRL). Of the 232 product samples tested, benzylpenicillin was detected in 11 livestock products and 2 marine products. Benzylpenicillin concentrations were found to be lower than the MRL in 12 products; however, the concentration of benzylpenicillin was found to be greater than the MRL in 1 pork product. The limit of quantification (LOQ) for benzylpenicillin was found to be 0.001-0.002 mg/kg, with an average recovery of 90.4-115.3%. Calibrations showed good linearity of 0.995 over a range of 0.002-0.05 mg/kg.

• Korean Journal of Food Science and Technology
• /
• v.41 no.1
• /
• pp.7-10
• /
• 2009

An analytical method for the determination of flumequine in meats was developed and validated using high-performance liquid chromatography with fluorescence detection. The samples were mixed with sodium sulfate and extracted with ethyl acetate. After clean-up, the residues were dissolved in mobile phase. The calibration curves showed high linearity ($r^2$=0.9979) within the concentration range of 0.1-1.0 mg/kg. The limit of detection and limit of quantification were validated at 0.005 and 0.017 mg/kg, respectively. The recoveries in fortified meats ranged from 90.8 to 101.1%. The method was then validated in correspondence with the CODEX guidelines for flumequine residue in meats. Herein we monitored 150 samples of meats that were purchased in Korea (Seoul, Busan, Daegu, Daejeon, and Gwangju). Among the tested samples, flumequine was detected in 1 of beef and 1 of pork at levels in the range of 0.048-0.080 mg/kg. Overall, the flumequine residues in the tested samples were within the Maximun residue limit.