• Journal of Food Hygiene and Safety
• /
• v.37 no.1
• /
• pp.1-8
• /
• 2022

In this study, the pesticide residues in 106 commercial cereal grains were monitored from February to July 2021. For the investigation, 40 domestic and 66 imported products from large, small-to-medium sized offline and online distribution channels, were collected and analyzed by using the multiresidue method for 341 pesticides on GC/ECD, GC/NPD, GC/MSMS, UPLC/PDA, HPLC/FLD, LC/MSMS. Pesticides were detected in total of 8 samples (7.5%), of which one was from big box retailers, two from small and medium-sized distribution stores, and five from online shopping mall. Five (4.7%) samples were found to have pesticide residues greater than the maximum residue limits (MRLs). The detected pesticides in kidney beans (1 case), mung beans (6 cases), and sorghum (1 case), were MGK-264, chlorpyrifos, thiamethoxam, malathion, piperonyl butoxide, and pirimiphos-methyl. Specifically, an excessive amount of thiamethoxam was found from the imported mung bean (5 cases).

• Journal of Environmental Health Sciences
• /
• v.44 no.5
• /
• pp.444-451
• /
• 2018

Objectives: This study was carried out to provide safe seafood to the public through simultaneous analysis rapid inspections for residual veterinary drugs in 150 fishery products in 2016. Methods: Quinolones (9), Sulfonamides (14), Penicillins (2), Cephalosporins (3), Tetracyclines (4), Macrolides (4), Lincosamides (2), Pleuromutilin (1), Phenicols (4), benzylpyrimidines (2), Others (1) Malachite green (2), and Melamine (1) were analyzed for 49 species using by HPLC and HPLC-MSMS. Results: There were six unsuitable samples, five among fish and one for crustaceans. Within the standard detection were five fish. The antibiotics found were Quinolones (50%), Tetracyclines (33%) and Penicillins (17%). Conclusions: As a result of the experiment, there were six unsuitable samples, five for fish and one for crustaceans. The most prevalent antibiotics were Quinolones. The quinolone antibiotics are highly persistent in fish tissues, so they require more time than the withdrawal period for other common veterinary drugs. Careful attention is required when they are used in fish farms.

• Korean Journal of Veterinary Service
• /
• v.32 no.3
• /
• pp.281-286
• /
• 2009

Fluoroquinolones in muscle and egg were separated by liquid extraction and determined. The analysis was carried out using following conditions; C18 column ($150{\times}4.6mm$, $5{\mu}m$), mobile phase composed of D.W. (containing 0.4% triethylamine and phosphoric acid) : methanol : acetonitrile (780:100:120, v/v/v), quarternary pump at a flow rate of 0.9ml/min and $20{\mu}l$ of injection volume, fluorescence detector with EX 278nm/Em 456nm. The calibration range of seven fluoroquinolones showed linearity ($r^2{\geq}0.999$) at concentration range of $0.025{\sim}0.8{\mu}g/ml$. The recoveries in fortified muscle and egg represented more than 81.3%. The detection limits for ofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, danofloxacin, saraloxacin and orbifloxacin were 3.1, 2.5, 3.6, 1.7, 0.9, 2.5 and $2.1{\mu}g/kg$, respectively. We also monitored fluoroquinolones residue in the sample (chicken muscle 182, cattle muscle 140, pig muscle 139, egg 212) using EEC-plate (E. coli ATCC 11303) screening and HPLC confirmation methods. The screening test results, fluoroquinolones, antibacterial substances were all negative.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.2
• /
• pp.291-294
• /
• 2006

A highly sensitive high-performance liquid chromatographic-tandem mass spectrometric method (HPLC-MSMS) has been developed to quantify itraconazole in human plasma for the purpose of pharmacokinetic studies. Sample preparation was carried out by liquid-liquid extraction using loratadine as an internal standard. Chromatographic separation used a YMC $C_{18}$ column, giving an extremely fast total run time of 3 min. The method was validated and used for the bioequivalence study of itraconazole tablets in healthy male volunteers (n = 31). The lower limit of detection proved to be 0.2 ng /mL for itraconazole.

• Korean Journal of Environmental Agriculture
• /
• v.39 no.2
• /
• pp.122-129
• /
• 2020

BACKGROUND: Dissipation patterns of insecticides (acequinocyl, clothianidin, diflubenzuron, thiacloprid, and thiamethoxam) on strawberry grown in plastic-covered greenhouse were evaluated at 7 intervals including the preharvest interval after application. This study was performed to determine the residue concentrations, half-lives and dissipation rates in strawberry for the harvest periods. METHODS AND RESULTS: Acequinocyl, clothianidin, diflubenzuron, thiacloprid, and thiamethoxam were applied in accordance with critical good agricultural practices for strawberry. Strawberry samples were collected at 0, 1, 2, 3, 5, 7 and 10 days after application. Quantitaion was performed by HPLC/DAD and HPLC-MSMS system with C₁₈ column. The limit of quantitation (LOQ) values varied between were 0.00025~0.05 mg/kg on strawberry. The recoveries of acequinocyl, clothianidin, diflubenzuron, thiacloprid and thiamethoxam at two concentrations ranged from 70.9~104.9% on strawberry. The half-lives of pesticide dissipation on strawberry for two fields ranged from 1.3~8.2 days. The dissipation rates were evaluated according to the statistics method with a 95% confidence. CONCLUSION: The residue levels of insecticides (acequinocyl, clothianidin, diflubenzuron, thiacloprid, and thiamethoxam) on strawberry at 0-day after application were below the specified values by Korean MRL. To estimate dissipation rate constant of pesticides on crop for harvest periods, it is important to set the pre-harvest residue limit for human health and consumer protection in Korea.

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

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.34 no.3
• /
• pp.157-165
• /
• 2008

In the previous study, the anti-oxidant activity of oxtract/fraction of Sueada aspparagoides(SA) and the stability test for the cream containing SA extract were investigated respectively[1,2]. In this study, the components of SA extract were analyzed by TLC, HPLC, and LC/ESI-MS/MS, $^1H$-NMR. TLC chromatogram of ethyl acetate fraction of SA extract revealed 5 bands $(SA1{\sim}SA5)$. HPLC chromatogram of aglycone fractions obtained from deglycoylation reaction of ethyl acetate fraction showed 2 bands (SAA 2 and SAA 1), which were identified as quercetin (composition ratio, 16.88%) and kaempferol (83.12%) in the order of elution time. Among 5 bands of TLC chromatogram, 4 bands $(SA2{\sim}SA5)$ also were Identified as kaempferol-3-O-glucoside (SA 2), quercetin-3-O-glucoside (SA3), kaempferol-3-O-rutinoside (SA 4), quercetin-3-O-rutinoside (SA 5) by LC/ESI-MS/MSMS/MS. respectively. The spectrum generated for SAA 1 by LC/ESI-MS/MS in the negative ion mode also gave the ion corresponding to the deprotonated aglycone $[M-H]^-$ (285m/z), the $^1H$-NMR spectrum contained signals [${\delta}$ 6.19 (1H, d, J=1.8Hz, H-6), ${\delta}$ 6.44 (1H, d, J=1.8Hz, H-8), ${\delta}$ 6.92 (2H, d, J=9.0Hz, H-3', 5'), ${\delta}$ 8.04 (2H, d, J=9.0Hz, H-2', 6', thus SAA 1 was identified as kaempferol. SAA 2 yielded the deprotonated agycone ion $[M-H]^-$ (301m/z), $^1H$-NMR spectrum showed signals [${\delta}$ 6.20 (1H, d, J=2.0Hz, H-6), ${\delta}$ 6.42 (1H, d, J=2.0Hz, H-8), ${\delta}$ 6.90 (1H, d, J=8.6Hz, H-5'), ${\delta}$ 7.55 (1H, dd, J=8.6, 2.2Hz, H-6'), ${\delta}$ 7.69 (1H, d, J=2.2Hz, H-2', thus SAA 2 was Identified as quercetin. In conclusion, with the anti-oxidant activity and the stability test reported previously, component analysis of SA extracts could be applicable to new cosmeceuticals.