• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.151-162
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• 2012

This study was carried out to establish Korean total diet study (TDS) model for estimating pesticide residue in food samples. In addition, pesticide residues of food samples were monitored by setting the standards of established Korean total diet study model. For monitoring, first step were selection of total 102 species food samples, second step were selection of total 70 species food samples, and third step were selection of total 12 representative diet and 109 species food samples. Ninety-eight pesticides were analyzed using $GC-{\mu}ECD$, GC-MS, and LC-MS/MS after QuEChERS sample preparation method. The residue levels in detected food samples were below the maximum residue limit (MRL). Establishment of the Korean total diet study model means providing safe food for consumers, secure the safety of food samples and provide ongoing information to agricultural producers about use of pesticides.

• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.37-48
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• 2010

The diacylhydrazine insecticides, methoxyfenozide, chromafenozide and tebufenozide are new-generation insecticides. These insecticides induce premature molting and cause the death of insects by mimicking their hormone. Also, these insecticides have already been widely used for vegetables planting in worldwide. Highperformance liquid chromatography (HPLC) is the most widely used procedure for determination of each compound residues in crops. However, simultaneous analysis method of these diacylhydrazine insecticides was not reported. The purpose of this study is to develop a simultaneous determination procedure of methoxyfenozide, chromafenozide and tebufenozide residue in crops using HPLC-UVD/MS method. These insecticide residues were extracted with acetone from representative samples of five raw products which comprised hulled rice, soybean, apple, pepper, and Chinese cabbage. The extract was diluted with saline water, and dichloromethane partition was followed to recover these insecticides from the aqueous phase. Florisil column chromatography was additionally employed for final cleanup of the extracts. The analytes were quantitated by HPLCUVD/MS, using a $C_{18}$ column. The crops were fortified with each insecticide at two levels per crop. Mean recoveries ranged from 89.0 to 104.8% in five representative agricultural commodities. The coefficients of variation were less than 3.9%. Quantitative limits of methoxyfenozide, chromafenozide and tebufenozide were 0.04 mg/kg in crop samples. A HPLC-UVD/MS with selected-ion monitoring was also provided to confirm the suspected residues. The proposed simultaneous analysis method was reproducible and sensitive enough to determine the residues of methoxyfenozide, chromafenozide and tebufenozide in agricultural commodities.

• Parasites, Hosts and Diseases
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• v.53 no.3
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• pp.321-327
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• 2015

A 50-year-old male visited the outpatient clinic and complained of fever, poor oral intake, and weight loss. A chest X-ray demonstrated streaky and fibrotic lesions in both lungs, and chest CT revealed multifocal peribronchial patchy ground-glass opacities with septated cystic lesions in both lungs. Cell counts in the bronchoalveolar lavage fluid revealed lymphocyte-dominant leukocytosis, and further analysis of lymphocyte subsets showed a predominance of cytotoxic T cells and few T helper cells. Video-assisted wedge resection of the left upper lobe was performed, and the histologic examination was indicative of a Pneumocystis jirovecii infection. Trimethoprim-sulfamethoxazole (TMP-SMX) was orally administered for 3 weeks; however, the patient complained of cough, and the pneumonia was aggravated in the follow-up chest X-ray and chest CT. Molecular studies demonstrated mutations at codons 55 and 57 of the dihydropteroate synthase (DHPS) gene, which is associated with the resistance to TMP-SMX. Clindamycin-primaquine was subsequently administered for 3 weeks replacing the TMP-SMX. A follow-up chest X-ray showed that the pneumonia was resolving, and the cough was also alleviated. A positive result of HIV immunoassay and elevated titer of HCV RNA indicated HIV infection as an underlying condition. This case highlights the importance of careful monitoring of patients with P. jirovecii pneumonia (PCP) during the course of treatment, and the molecular study of DHPS mutations. Additionally, altering the anti-PCP drug utilized as treatment must be considered when infection with drug-resistant P. jirovecii is suspected. To the best of our knowledge, this is the first case of TMP-SMX-resistant PCP described in Korea.

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

• Food Science and Preservation
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• v.15 no.4
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• pp.550-555
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• 2008

This study analyzed 102 samples from 24 local areas to monitor patulin contamination of apples for processing by the areas. According to the analysis, patulin was detected in 47 samples among totally 92 ones and those of 15 samples from 12 areas were found to be 50 or more ppb so measures to deal with the patulin contamination were necessary. As ways to reduce residues of patulin, when 200 ppm ascorbic acid were treated with they was decreased by 93.4% to 12.89 ppb, and when 100 ppm activated carbon was added they were declined by 95.8% to 2.68 ppb. Treatment with pectinase did not show any significant difference and effects of temperature was not considerable under established sterilizing conditions(90, 105, 120, 135 and $150^{\circ}C$/25 sec). In conclusion, treatment with ascorbic acid and activated carbon on apple juice was found to decrease residues of patulin but more systemic researches were needed to determine it in the future.

• Analytical Science and Technology
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• v.18 no.6
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• pp.511-519
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• 2005

A method for determination of toluene diisocyanates (TDI) in toluene diisocynate (TDI)-based polyurethane (PUR) packing material was investigated, and also the migration of TDI to food was studied. TDI was extracted using food simulants such as n-haptane and 4% aqueous acetic acid. The determinations were performed using gas chromatography/mass spectrometry (GC/MS). One of major components for polyurethane, toluene diisocyanates, were detected in ten samples among twenty six food contact materials with the concentration range of $0.51{\sim}60.88{\mu}g/ml$. However the highest extracted amount was just 0.7% of $60.88{\mu}g/ml$ if the contact surface of food packing for extracting liquid was limited to the outer layer without exposure of the cutting edge of food packing multi-layers. The result of this study and the analysis method for TDI diisocyanate will be very useful for further study about food contact material, and the monitoring result could be used for evaluating the safety of food contact material before it is to be used for food, preservation.

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

• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.6-15
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• 2014

This study was performed to acquire the information on the foodborne pathogen risk management programs in a couple of developed countries by the expert meeting and searching the information on the web. The backgrounds, strategies and effects related to microbial hazards of the foodborne pathogen reduction programs in fresh produce (US), Escherichia coli O157:H7 in ground beef (US), Salmonella in chicken, pork and eggs (Denmark), and Vibrio parahaemolyticus in seafood (Japan) were investigated for case study. A comparison among the pathogen reduction programs was conducted to find advantages and disadvantages and implications of the policies to bring out implications of the programs. A model for foodborne pathogen reduction program was developed based on both the CODEX risk management scheme and the case studies as follows; 1) preliminary risk management activities, 2) planing a foodborne pathogen reduction program, 3) option identification and selection, 4) implementation (conducting the each stake-holders role and applying the intervention methods), 5) monitoring activities, 6) interim review, 7) continuation or amendment of implementation method by the interim review before achieving the goal, and 8) final review and additional cost-benefit analysis if necessary. This proposed model according to the role of the stake-holders can be used to conduct microbial risk management programs in Korea in the near future.

• Journal of fish pathology
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• v.32 no.1
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• pp.37-43
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• 2019

Due to the rapid global expansion of aquaculture industry during the past decades, production volume of aquatic organisms has accordingly grown. This has been accompanied by a rise in the incidence of diseases in aquatic organisms, leading to an increased use of aquatic medicines. While aquatic medicines are essential for the prevention and treatment of diseases of aquatic organisms, misuse can cause evolution of antibiotic-resistant bacteria and pose serious problems to the safety and hygiene of fisheries products. In this study, we surveyed and compared, by analyzing data compiled by all national control centers for aquatic animal diseases in South Korea, to estimate the amount of aquatic medicines sold in different regions between 2012 through 2015. Since we also examined the marketing routes of aquatic medicines, this basic data can be utilized for policy implementation to improve drug safety. In the future research, however, it will be clearly necessary to estimate directly the amounts of drugs actually applied to aquaculture organisms. The current sales figure data should be helpful for preparation of an effective system for aquatic drug use management.

• Journal of Food Hygiene and Safety
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• v.21 no.4
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• pp.231-237
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• 2006

Nowadays the teabag is worldwide used for various products including green tea, tea, coffee, etc. since it is convenient for use. In case of outer packaging printed, however, there is a possibility that the plasticizers which is used for improvement in adhesiveness of printing ink may shift to inner tea bag. In this study, in order to monitor residual levels of plasticizers in teabags, we have established the simultaneous analysis method of 9 phthalates and 7 adipates plasticizers using gas chromatography (GC). These compounds were also confirmed using gas chromatography-mass spectrometry (GC-MSD). The recoveries of plasticizers analyzed by GC ranged from 82.7% to 104.6% with coefficient of variation of $0.6\sim2.7%$ and the correlation coefficients of each plasticizer was $0.9991\sim0.9999$. Therefore this simultaneous analysis method was showed excellent reproducibility and linearity. And limit of detection (LOD) and limit of quantitation (LOQ) on individual plasticizer were $0.1\sim3.5\;ppm\;and\;0.3\sim11.5\;ppm$ respectively. When 143 commercial products of teabag were monitored, no plasticizers analysed were detected in filter of teabag products. The migration into $95^{\circ}C$ water as food was also examined and the 16 plasticizers are not detected. In addition we carried out analysis of heavy metals, lead (Pb), cadmium (Cd), arsenic (As) and aluminum (Al) in teabag filters using ICP/AES. $Trace\sim23{\mu}g$ Pb per teabag and $0.6\sim1718{\mu}g$ Al per teabag were detected in materials of samples and Cd and As are detected less than LOQ (0.05 ppm). The migration levels of Pb and Al from teabag filter to $95^{\circ}C$ water were upto $11.5{\mu}g\;and\;20.8{\mu}g$ per teabag, respectively and Cd and As were not detected in exudate water of all samples. Collectively, these results suggest that there is no safety concern from using teabag filter.