• Toxicological Research
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• v.33 no.3
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• pp.225-231
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• 2017

National reference standards (NRSs) for biologics are established through potency estimation by a multi-center joint study of standard materials used in the approval process for national lot release and quality control of vaccines, blood products, and other biologics. In this study, a stability evaluation was conducted to determine whether the potency of NRSs for six blood products was being maintained at a consistent level in Korea. The present study conducted real-time stability tests via in-vivo/in-vitro bioassay on NRSs for blood coagulation factor VIII concentrate (2nd standard), antithrombin concentrate, prekallikrein activator, anti-hepatitis B immunoglobulin, blood coagulation factor IX concentrate, and anti-tetanus human immunoglobulin, as well as a trend analysis using cumulative annual results. The real-time stability test results showed that the mean potency of six NRSs was all within the control limit. In the trend analysis, the potency of NRS for blood coagulation factor VIII concentrate (2nd standard) showed a decreasing trend, while the potency of all other products had been stably maintained. The present study confirmed that the mean potency of NRSs for six blood products had been stably maintained in Korea. The findings of the present study establish a foundation that can ensure the quality of NRSs for biologics in Korea, and it is expected to make a major contribution to the supply of high-quality biologics.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.30-39
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• 2019

An analytical method was developed for the determination of sedaxane in agricultural products using liquid chromatograph-tandem mass spectrometry (LC-MS/MS). The samples were extracted with acetonitrile and partitioned with dichloromethane to remove the interference, and then purified by using silica SPE cartridges to clean up. The analytes were quantified and confirmed by using LC-MS/MS in positive ion mode using multiple reaction monitoring (MRM). The matrix-matched calibration curves were linear over the calibration ranges ($0.001-0.25{\mu}g/mL$) into a blank extract with $r^2$>0.99. For validation, recovery tests were carried out at three different concentration levels (LOQ, 10LOQ, and 50LOQ, n=5) with five replicates performed at each level. The recoveries were ranged between 74.5 to 100.8% with relative standard deviations (RSDs) of less than 12.1% for all analytes. All values were consistent with the criteria ranges requested in the Codex guidelines (CAC/GL 40, 2003) and Food Safety Evaluation Department guidelines (2016). The proposed analytical method was accurate, effective and sensitive for sedaxane determination in agricultural commodities.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.13-21
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• 2019

A method was developed for the simultaneous detection of an antibiotic fungicide, streptomycin, and its metabolite (dihydrostreptomycin) in agricultural products using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted using methanol adjusted to pH 3 using formic acid, and purified with a HLB (Hydrophilic lipophilic balance) cartridge. The matrix-matched calibration curves were constructed using seven concentration levels, from 0.001 to 0.1 mg/kg, and linearity of five agricultural products (hulled rice, potato, soybean, mandarin, green pepper), with coefficients of determination $(R^2){\geq}0.9906$, for streptomycin and dihydrostreptomycin. The mean recoveries at three fortification levels (LOQ, $LOQ{\times}10$, $LOQ{\times}50$, n = 5) were from 72.0~116.5% and from 72.1~116.0%, and relative standard deviations were less than 12.3% and 12.5%, respectively. The limits of quantification (LOQ) were 0.01 mg/kg, which are satisfactory for quantification levels corresponding with the Positive List System. All optimized results satisfied the criteria ranges requested in the Codex guidelines and the Food Safety Evaluation Department guidelines. The present study could serve as a reference for the establishment of maximum residue limits and be used as basic data for detection of streptomycin and dihydrostreptomycin in food.

• Safe Food
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• v.8 no.1
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• pp.36-40
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• 2013

• Analytical Science and Technology
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• v.25 no.1
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• pp.76-82
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• 2012

The determination and confirmation of dutasteride in human serum was performed by a liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS). Beclomethasone as an internal standard (I.S.) was added to the serum and the mixed sample was pretreated by liquid-liquid extraction (LLE) with methyl tert-butyl ether (MTBE). The mass transitions of dutasteride and I.S. monitored in multiple reaction monitoring (MRM) were m/z 529.6${\rightarrow}$461.5 and m/z 409.3${\rightarrow}$391.2, respectively, and the retention times were 6.45 and 5.46 min, respectively. The calibration curve was linear in the concentration range of 0.5~30.0 ng/mL ($R^2$= 0.9999) and the limit of quantitation (LOQ) was found to be 0.5 ng/mL. The recovery of dutasteride was shown to be 66~72%. The intra-day assay precision and accuracy were in the range 3.5~5.5% and 85.7~89.9%, respectively, and the interday assay precision and accuracy were in the range 4.2~5.8% and 90.8~95.8%, respectively.

• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.47-52
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• 2014

This study was performed to evaluate antimicrobial resistance of food-borne pathogens isolated from retail meat in Korea. A total of 157 samples of beef, pork, and chicken were collected and analyzed for E. coli, Salmonella, Campylobacter. Resistances to tetracycline were declined in accord with reduced usage of tetracycline in live stock production. E. coli stains from chicken meat had higher multi-drug resistance ratio than strains from other meat. One extended spectrum beta lactamase (ESBL) producing E. coli and two ESBL producing Salmonella were identified in this study. ESBL producing Salmonella strains were confirmed to carry CTX-M-1 type genes.

• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.188-193
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• 2013

Anatoxin-a, saxitoxin and neosaxitoxin are produced by Aphanizomenon flos-aquae that is a sort of the cyanobacteria phylum. Therefore, it is not permitted for food materials in Korea. Traditionally, the classification of cyanobacteria has been based on morphological characters such as trichome width, cell size, division planes, shape, and the presence of character such as gas vacuole. But, some diagnostic features, such as gas vacuole or akinetes, can show variation with different environmental or growth conditions and even be lost during cultivation. Therefore, we developed detection method for functional foods containing Aph. flos-aquae by PCR. To design the primer, 16S rRNA region of Aph. flos-aquae, Spirulina laxissima, and Spirulina spp. registered in the GeneBank (www.ncbi.nlm.nih.gov) have been used and for comparative analysis, BioEdit ver. 7.0.9.0. was used. As a result, we was design AFA-F1/AFA-R1 (363 bp) primer for the differentiation Aph. flos-aquae from chlorella, spirulina, green tea, and spinach. Also, it could be distinguished chlorella and spirulina products those are made to contain 1% Aph. flos-aquae.

• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.214-223
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• 2013

BACKGROUND: This study focused on the development of an analytical method about dichlorprop (DCPP; 2-(2,4-dichlorophenoxy)propionic acid) which is a plant growth regulator, a synthetic auxin for agricultural commodities. DCPP prevents falling of fruits during their growth periods. However, the overdose of DCPP caused the unwanted maturing time and reduce the safe storage period. If we take fruits with exceeding maximum residue limits, it could be harmful. Therefore, this study presented the analytical method of DCPP in agricultural commodities for the nation-wide pesticide residues monitoring program of the Ministry of Food and Drug Safety. METHODS AND RESULTS: We adopted the analytical method for DCPP in agricultural commodities by gas chromatograph in cooperated with Electron Capture Detector(ECD). Sample extraction and purification by ion-associated partition method were applied, then quantitation was done by GC/ECD with DB-17, a moderate polarity column under the temperature-rising condition with nitrogen as a carrier gas and split-less mode. Standard calibration curve presented linearity with the correlation coefficient ($r^2$) > 0.9998, analysed from 0.1 to 2.0 mg/L concentration. Limit of quantitation in agricultural commodities represents 0.05 mg/kg, and average recoveries ranged from 78.8 to 102.2%. The repeatability of measurements expressed as coefficient of variation (CV %) was less than 9.5% in 0.05, 0.10, and 0.50 mg/kg. CONCLUSION(S): Our newly improved analytical method for DCPP residues in agricultural commodities was applicable to the nation-wide pesticide residues monitoring program with the acceptable level of sensitivity, repeatability and reproducibility.

• Journal of Food Hygiene and Safety
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• v.27 no.3
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• pp.317-324
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• 2012

In order to determine an authenticity of food ingredient, we used DNA barcode method by universal primers. For identification of animal food ingredients, LCO1490/HCO2198 and VF2/FISH R2 designed for amplifying cytochrome c oxidase subunit1 (CO1) region and L14724/H15915 for cytochrome b (cyt b) region on mitochondrial DNA were used. Livestock (cow, pig, goat, sheep, a horse and deer) was amplified by LCO1490/HCO 2198, VF2/FISH R2 and L14724/H15915 primers. Poultry (chicken, duck, turkey and ostrich) was amplified by LCO1490/HCO 2198 and VF2/FISH R2 primers. But, Fishes (walleye pollack, herring, codfish, blue codfish, trout, tuna and rockfish) were only amplified by VF2/FISH R2 primers. For plant food ingredients, 3 types of primers (trnH/psbA, rpoB 1F/4R and rbcL 1F/724R) have been used an intergenic spacer, a RNA polymerase beta subunit and a ribulose bisphosphate carboxylase region on plastid, respectively. Garlic, onion, radish, green tea and spinach were amplified by trnH/psbA, rpoB 1F/4R and rbcL 1F/724R. The PCR product sizes were same by rpoB 1F/4R and rbcL 1F/724R but, the PCR product size using trnH/psbA primer was different with others for plants each. We established PCR condition and universal primer selection for 17 item's raw materials for foods and determine base sequences aim to PCR products in this study. This study can apply to determine an authenticity of foods through making an comparison between databases and base sequences in gene bank. Therefore, DNA barcode method using universal primers can be a useful for species identification techniques not only raw materials but also processed foods that are difficult to analyze by chemical analysis.

• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.235-242
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• 2014

The purpose of this study is the establishment of scientific processes for making food safety policies. Thus, we investigated pesticide residue level of the agricultural commodities from market, and performed risk assessment. Fifteen agricultural items are chosen based on the frequency of Korean consumption. The samples were collected from 9 cities where populations are more than one million. Total 283 active ingredients were monitoring ( total sample number =232). Single-analysis of target pesticides was for three kinds of possible growth regulators and the multicomponent analysis was for 280 kinds of pesticides, a total of 283 species were selected to perform the pesticide residues. Before monitoring the analytes, the improvements of the analytical methods were done by method validations under the CODEX analytical method development guidelines and can produce metrics that represent the international standards applied in accordance with the guidelines. In addition to residual pesticides detected during monitoring we compare the ADI to EDI values using detected result and dietary consumption data which is extracted from annual market basket survey. The 163 samples were non-detected in the total 232 samples so it means that every agricultural commodity will residual pesticides-free in 70.3%. The detected residual pesticides showed for a total of 69 cases (29.7%). Two of samples violate Korean MRL (0.9%). The ratio of EDI compared to ADI resulted in only from 0.00087 to 0.902%. In result, we can assume that all detected residual pesticides are very safe level and current policies of Korean pesticides control may be working.