• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.190-190
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• 2002

Methamphetamine (META) is a psychostimulant and has become popular recreational drug of abuse in many countries. The neurotoxic damage caused by METH is characterized by degeneration of the dopaminergic and serotonergic systems in striatum and hippocampus.(omitted)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.396.2-396.2
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• 2002

Analytical results during the proficiency test managed by Kyungin Regional Korea Food ＆ Drug Administration were proposed to be influenced by several factors. Data of several factors were collected along with the test results with ibuprofen and sobrerol formulations. The collected data were the use of internal standard, academic background and career of analytical personnel, production size of the company and location of the participating laboratory. (omitted)

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.156.2-156.2
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• 2001

• Journal of Food Hygiene and Safety
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• v.34 no.2
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• pp.115-123
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• 2019

An analytical method was developed for the determination of fenpropimorph, a morpholine fungicide, in hulled rice, potato, soybean, mandarin and green pepper using QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) sample preparation and LC-MS/MS (liquid chromatography-tandem mass spectrometry). The QuEChERS extraction was performed with acetonitrile followed by addition of anhydrous magnesium sulfate and sodium chloride. After centrifugation, d-SPE (dispersive solid phase extraction) cleanup was conducted using anhydrous magnesium sulfate, primary secondary amine sorbents and graphitized carbon black. The matrix-matched calibration curves were constructed using seven concentration levels, from 0.0025 to 0.25 mg/kg, and their correlation coefficient ($R^2$) of five agricultural products were higher than 0.9899. The limits of detection (LOD) and quantification (LOQ) were 0.001 and 0.0025 mg/kg, respectively, and the limits of quantification for the analytical method were 0.01 mg/kg. Average recoveries spiked at three levels (LOQ, $LOQ{\times}10$, $LOQ{\times}50$, n=5) and were in the range of 90.9~110.5% with associated relative standard deviation values less than 5.7%. As a result of the inter-laboratory validation, the average recoveries between the two laboratories were 88.6~101.4% and the coefficient of variation was also below 15%. All optimized results were satisfied the criteria ranges requested in the Codex guidelines and Food Safety Evaluation Department guidelines. This study could serve as a reference for safety management relative to fenpropimorph residues in imported and domestic agricultural products.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.397.2-397.2
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• 2002

Sildenafil citrate(SC. Viagra(equation omitted)) is the oral treatment for erectile dysfunction. Vardenafil hydrochloride. tadalafil and modified sildenafil have anti-impotent effect and have possibility to be used illegally. The aim of this study was to set up simultaneous determination method of anti-impotent drugs using TLC and HPLC. The anti-impotent drugs were extracted with 50% methanol and then diluted with mobile phase for HPLC and also extracted with developing solvents as sample solutions for TLC. (omitted)

• Journal of Food Hygiene and Safety
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• v.34 no.2
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• pp.140-147
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• 2019

An analytical method was developed for the determination of quinoxyfen in agricultural products using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted with 1% acetic acid in acetonitrile and water was removed by liquid-liquid partitioning with $MgSO_4$ (anhydrous magnesium sulfate) and sodium acetate. Dispersive solid-phase extraction (d-SPE) cleanup was carried out using $MgSO_4$, PSA (primary secondary amine), $C_{18}$ (octadecyl) and GCB (graphitized carbon black). The analytes were quantified and confirmed by using LC-MS/MS in positive mode with MRM (multiple reaction monitoring). The matrix-matched calibration curves were constructed using six levels ($0.001-0.25{\mu}g/mL$) and the coefficient of determination ($R^2$) was above 0.99. Recovery results at three concentrations (LOQ, 10 LOQ, and 50 LOQ, n=5) were in the range of 73.5-86.7% with RSDs (relative standard deviations) of less than 8.9%. For inter-laboratory validation, the average recovery was 77.2-95.4% and the CV (coefficient of variation) was below 14.5%. All results were consistent with the criteria ranges requested in the Codex guidelines (CAC/GL 40-1993, 2003) and Food Safety Evaluation Department guidelines (2016). The proposed analytical method was accurate, effective and sensitive for quinoxyfen determination in agricultural commodities. This study could be useful for the safe management of quinoxyfen residues in agricultural products.

• Journal of Food Hygiene and Safety
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• v.31 no.5
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• pp.327-334
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• 2016

This study was conducted to establish the standard method for the contents of biotin in milk formulas. To optimize the method, we compared several conditions for liquid extraction, purification and instrumental measurement using spiked samples and certified reference material (NIST SRM 1849a) as test materials. LC-MS/MS method for biotin was established using $C_{18}$ column and binary gradient 0.1% formic acid/acetonitrile, 0.1% formic acid/water mobile phase is applied for biotin. Product-ion traces at m/z 245.1 ${\rightarrow}$ 227.1, 166.1 are used for quantitative analysis of biotin. The linearity was over $R^2=0.999$ in range of $5{\sim}60{\mu}g/L$. For purification, chloroform was used as a solvent for eliminating lipids in milk formula. The linearity was over 0.999 in range of 5~60 ng/mL. The detection limit and quantification limit were 0.10, 0.31 ng/mL. The accuracy and precision of LC-MS/MS method using CRM were 103%, 2.5% respectively. Optimized methods were applied in sample analysis to verify the reliability. All the tested milk formulas were acceptable contents of biotin compared with component specification and standards for nutrition labeling. The standard operating procedures were prepared for biotin to provide experimental information and to strengthen the management of nutrient in milk formula.

• Journal of Biomedical Engineering Research
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• v.31 no.6
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• pp.434-437
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• 2010

For approval of medical devices manufactured or imported, submission of technical documents as well as the application form is required. The manufacturer (or importer) should properly identify the raw materials the applied product is made of and the manufacturing processes the product undergoes before it is shipped in the application form. In the technical documents, scientific data to evaluate the efficacy, safety, and quality of the applied product that has been described in the application form should be provided. Therefore, identifying the raw materials that were used for the parts of the applied product and describing the physical and chemical characteristics of the raw materials are quite important and essential in ensuring the efficacy, safety, and quality of the applied product. To describe the physical and chemical characteristics of the raw materials correctively, the applicant is required to have broad knowledge in the scientific fields such as chemical, polymer, metal, and ceramic science and engineering. But most of the applicant are not experts in these fields, so that the description in the application form often includes wrong and improper descriptions. Thus, we developed a guideline which explains the raw materials for medical devices, show the their examples. The purpose of this description guideline is to help the applicant properly completing the "Raw materials or constituents and their volumes" part in the application form.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.11a
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• pp.103-103
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• 2004

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.285.2-286
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• 2001