• Applied Biological Chemistry
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• v.38 no.2
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• pp.179-183
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• 1995

The brassinosteroid-like active principles from immature seeds of Zea mays were purified and identified as castasterone, teasterone, 28-norcastasterone and 6-deoxocastasterone by GC-MS analysis. Our work is probably the first report that showed the presence of brassinosteroids in Zea mays seeds.

• Analytical Science and Technology
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• v.28 no.3
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• pp.221-227
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• 2015

Animal glue is a traditional material that was used widely as an adhesive in cultural artifacts, such as Buddhist paintings, dancheong (traditional multicolored paintwork on wooden buildings), mother-of-pearl inlay, and so on. Spectroscopic methods, such as infrared spectroscopy, have been used for the analysis of animal glue. However, such methods do not yield sufficient information about the constituents of the glue. Because pyrolysis/GC/MS analysis is able to estimate the components of a material through the examination of its pyrolyzed products, it is useful for the analysis of polymeric material. In this study, pyrolysis/GC/MS analysis was used to determine the chemical composition of animal glue. The appropriate conditions for analyzing animal glue were established by examining pyrolysis temperature, quantity of the sample, and the repeatability of the method. Some products of pyrolysis were identified. We also analyzed commercial gelatin and animal glue using the established method and found almost no differences in chromatograms among the samples. The results will be used as supporting data to confirm the use of animal glue in cultural artifacts and to replace traditional animal glue by commercial gelatin.

• The Korea Journal of Herbology
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• v.26 no.1
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• pp.7-12
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• 2011

Objectives : The purpose of this study is to evaluate the quality of four different kinds of agarwood and analysis chemical constituents by GC-MS. Methods : Four source plants were two of Vietnamese agarwood, Indonesian agarwood and Myanmar agarwood. These plant materials were named sample No. 1-4. The chemical constituents of each agarwood were analysed by GC-MS. Results : GC-MS analysis showed that ${\beta}$-selinene was found in all the samples. The Vietnamese agarwood, Sample 1, and 4 has contained 6.861% and 7.497% of ${\beta}$-selinene and reached the highest level at the retention times 46.245 and 46.274 (min). Sample 2, the Myanmar agarwood has contained 1.608%, the lowest level of ${\beta}$-selinene, and it also has contained about 20% of ${\alpha}-,{\beta}-,{\gamma}$-eudesmol and 4.076% of valerianol. Sample 3, the Indonesian agarwood has contained 9.59% of ${\beta}$-selinene, 9.493% of ${\beta}$-selinene and shown its highest level (more than 19%) at the retention time 43.998 (min). Conclusion : It suggested that ${\beta}$-selinene could be a standard marker to evaluate agarwood by GC-MS analysis.

• Analytical Science and Technology
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• v.13 no.4
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• pp.412-422
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• 2000

The polymeric FAB materials of air shower used in clean room of wafer industry have been outgassed with the dynamic headspace (ca.$100^{\circ}C$) for half an hour, and analyzed using GC-MS. The air in the clean room running air shower was sampled using sorbent tube method, and the organic compounds adsorbed in the sorbent tube were extracted using Soxhlet extraction method, and analyzed using GC-MS. The analytical results from FAB materials of air shower (electric over current relay, acryl plate. polycarbonate window, filter, fan housing, steel galvanized cold plate and canvas buffer) indicated that most of chemicals were originated from polymer fragments of FAB materials. Their analytical results have been compared with those from the air of clean room running air shower. These comparative results could lead to identify whether the sources of trace organic contaminants in clean room air are originated from the polymeric FAB material of air shower.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.110-117
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• 2018

The aim of this study was to develop an analytical method for the quantification of diazepam residues in fishery products, using liquid and gas chromatography-tandem mass spectrometry (LC-MS/MS and GC-MS/MS). The sample utilized in the study was extracted from the fish sample (crucian carp) using 0.1% formic acid in acetonitrile. For the utilization of the purification process, the dispersive solid phase extraction (dSPE) was used for LC-MS/MS, dSPE and SPE was used for GC-MS/MS, respectively. To be sure, the standard calibration curves showed a good linearity as the noted correlation coefficients, $r^2$ was > 0.99. The average recoveries for accuracy ranged in 99.8~124% for the samples which were fortified at three different levels (0.001, 0.002 and 0.010 mg/kg). The correlation coefficient for the precision effect was measured at a range of 4.01~11.8%. The limit of detection (LOD) for the diazepam analysis was 0.0004 mg/kg, and the limit of the quantification (LOQ) was 0.001 mg/kg. The proposed analytical method was characterized with a high accuracy and acceptable sensitivity to meet the established Codex Alimentarius Commission (CAC/GL71-2009) guideline requirements. We therefore established the optimal analysis method for the determination of diazepam in the fishery products using LC-MS/MS and GC-MS/MS. It would be applicable to analyze the diazepam residues in fishery products in further studies on this subject.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.37-40
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• 2011

화재현장에서는 화재의 원인으로 간주되는 여러 가지 증거물이 발생한다. 이러한 증거물을 분석하기 위한 수단으로 GC/MS의 역할은 아주 크며, 이를 이용한 증거물의 분석에 관한 표준으로 ASTM 1618-10과 전처리법을 소개한다. 또한 전처리법에 따른 여러 가지 종류의 유류의 특성을 알아보고 유류 성분을 포함한 화재증거물의 실제 사례를 들어 보겠다. 아울러 화재현장에서의 가연물로 추정되는 물질에 대하여 열분해를 통한 GC/MS 분석 사례도 제시하여 본다.

• Journal of Korean Society on Water Environment
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• v.32 no.5
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• pp.410-418
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• 2016

This study was conducted to improve the analysis method used for N-nitrosamines and to investigate the occurrences of N-nitrosamines in tributaries of the Han-river, intake stations, water treatment plants and tap water used within the city of Seoul. The samples were pretreated through a solid phase extraction and analyzed using a gas chromatography tandem mass spectrometer (GC-MS/MS). The GC-MS/MS in CI mode was compared with the GC-MS/MS in EI mode by the method detection limits (MDLs). MDLs by GC-CI/MS/MS and GC-EI/MS/MS were 0.2 ~ 1.1 ng/L and 0.2 ~ 1.4 ng/L, respectively. Samples were collected from ten tributaries of the Han-river (T1 ~ T10), six intake stations (I1 ~ I6), six water treatment plants (P1 ~ P6) and 25 taps in Seoul city. The maximum levels of N-nitrosodimethylamine (NDMA) were 0.013 μg/L, 0.008 μg/L, 0.006 μg/L and 0.002 μg/L in tributary water, raw water, finished water and tap water samples, respectively. Detected levels were much lower than 0.1 μg/L corresponding to the guideline value of WHO.

• Analytical Science and Technology
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• v.22 no.3
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• pp.210-218
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• 2009

A gas chromatography-tandem mass spectrometry (GC-MS/MS) method was developed and validated for simultaneous determination of amphetamine derivatives and norketamine in human hair. Preparation of hair involves external decontamination, mechanical pulverization, incubation and extraction prior to instrumental analysis. The samples were derivatized using heptafluorobutyric anhydride, and analyzed by GC-MS/MS. The linear ranges were 0.05-20.0 ng/mg for the analytes except for 3,4-methylenedioxyamphetamine, with good coefficients of determination ($r^2$ >0.998). The intra-day and inter-day precisions were within 10.7% and 8.5%, respectively. The intra-day and inter-day accuracies were between -1.6 and 17.0% and -2.6 and 10.5%, respectively. The limits of detections for each analyte were lower than 0.007 ng/mg, while recoveries were 75.9-100.9%. When the method was applied to hair samples obtained from suspected drug abusers, the concentrations in hair samples were 0.97-19.30 ng/mg for methamphetamine and 0.14-2.56 ng/mg for amphetamine.

• Journal of Microbiology and Biotechnology
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• v.16 no.7
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• pp.1139-1143
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• 2006

Various techniques and strategies have been developed for the identification of intracellular metabolic conditions, and among them, isotope balance-based flux analysis with gas chromatography/mass spectrometry (GC/ MS) has recently become popular. Even though isotope balance-based flux analysis allows a more accurate estimation of intracellular fluxes, its application has been restricted to relatively small metabolic systems because of the limited number of measurable metabolites. In this paper, a strategy for incorporating isotope balance-based flux data obtained for a small network into metabolic flux analysis was examined as a feasible alternative allowing more accurate quantification of intracellular flux distribution in a large metabolic system. To impose GC/MS based data into a large metabolic network and obtain optimum flux distribution profile, data reconciliation procedure was applied. As a result, metabolic flux values of 308 intracellular reactions could be estimated from 29 GC/ MS based fluxes with higher accuracy.

• Analytical Science and Technology
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• v.25 no.6
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• pp.410-415
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• 2012

In this study, a fundamental study was conducted to establish the method for quantitative analysis and pretreatment of triclosan, one of the chemicals to be used as bactericides, detergents, and sterilizers. The extraction efficiency of triclosan was the highest when it was extracted by soxhlet apparatus with n-hexane, and it showed a satisfactory result when the samples were analyzed with both GC/ECD and GC/MS. To evaluate the reproductivity of the results, each 30 reference samples made with paper filter and cotton wool was prepared in this study. From the results with high extraction effectiveness, low analysis deviation, and good statistical analysis data, the method for the extraction and analysis for triclosan were resonable for the paper and textile samples applied in this study.