• Mass Spectrometry Letters
• /
• 제2권2호
• /
• pp.33-36
• /
• 2011

The misuse of anabolic androgenic steroids is of particular concern in sports and society. Thus, it is of great importance to discriminate endogenous steroids such as testosterone or testosterone prohormones from their chemically identical synthetic copies. In this study, gas chromatography-combustion/isotope ratio mass spectrometric (GC-C/IRMS) method has been developed and validated for discriminating the origin of anabolic androgenic steroids. The method involves the solid-phase extraction, enzymatic hydrolysis with ${\beta}$-glucuronidase, HPLC-fractionation for the cleanup and analysis by GC-C/IRMS. The difference(${\Delta}^{13}C$) of urinary ${\delta}^{13}C$ values between synthetic analogues and endogenous reference compounds (ERC) by GC-C/IRMS was used to elucidate the origin of steroids, and intra- and inter-day precision, specificity and isotope fractionation were evaluated. The present GC-C/IRMS method combined with HPLC cleanup was accurate and reproducible enough to be successfully applied to the test of urine sample from suspected anabolic steroid abusers.

• Bulletin of the Korean Chemical Society
• /
• 제27권9호
• /
• pp.1315-1322
• /
• 2006

The following study describes the gas chromatography-mass spectrometry (GC-MS) based screening and confirmation analysis of urinary androgenic steroids. Four commercially available solid-phase extraction (SPE) cartridges, Serdolit PAD-1, Sep-pak $C_{18}$, amino-propyl, and Oasis HLB, and three different extractive organic solvents, diethyl ether, methyl tert-butyl ether (MTBE), and n-pentane, were tested for sample preparation. Overall, Oasis HLB combined with MTBE extraction provided the highest recoveries in 39 of 46 total androgenic steroids examined and it showed a good extraction yield (>82.1%) for polar steroids, such as metabolites of fluoxymesterone, oxandrolone, and stanozolol, which gave a poor recovery in both n-pentane (9.2-64.3%) and diethyl ether (22.2-73.6%) extractions. All SPE sorbents tested showed potential, because they were efficient in extraction for most or selective steroids. When applied to positive urine samples based on the results obtained, the present method allowed selective and sensitive analysis for detection of urinary androgenic steroids. The experiments showed that the high-resolution MS method is clearly more efficient than the low-resolution MS technique for the detection of many urinary steroids. However, comprehensive sample clean-up procedures also might be needed especially in confirmation analysis to increase detectability.

• 분석과학
• /
• 제8권4호
• /
• pp.771-778
• /
• 1995

The authors have developed an analytical method for determining trace amounts of 285 kinds of chemicals in natural waters by GC-ion trap MS. The results of overall recovery tests at $0.1{\mu}g/l$ showed that the mean recovery was 92.1% and the mean relative standard deviation was 10.8%. The mean of the method detection limits was $0.036{\mu}g/l$. From the results of analysis of real samples, it was confirmed that this method is useful to elucidate the concentration levels and the fate of chemicals in the aquatic environment.

• Journal of Microbiology and Biotechnology
• /
• 제16권12호
• /
• pp.1990-1994
• /
• 2006

Fusarium proliferatum KGL0401 was previously isolated from Physalis alkekengi var. francheti plant roots and exhibited a high GA productivity. A gas chromatography-mass spectrometry (GC-MS) analysis of extracts of the culture fluid of F proliferatum KGL0401 also revealed the presence of $GA_1$, $GA_3$, $GA_4$, $GA_7$, $GA_{20}$, and $GA_{24}$. Therefore, the present study conducted a proteome analysis of waito-c rice treated with the culture fluid of the isolated F proliferatum KGL0401 to identify the protein expression triggered by the GA-containing culture fluid. The results revealed the overexpression of 180 protein spots in the sample treated with the culture fluid. Among them, 75 induced proteins were selected and analyzed by MALDI-TOF (matrix-assisted laser desorption-iorrization time-of-flight) mass spectrometry, followed by database searching, and 51 proteins were identified.

• Mass Spectrometry Letters
• /
• 제13권4호
• /
• pp.125-132
• /
• 2022

There are many types of spring blossoms on the Daedeok campus of Chungnam National University (CNU) at the area of 1,600,000 square meters. As an assignment for the class of Analytical Chemistry I for second-year undergraduate students, 2021, flower petals collected from various floral groups (Korean azalea, Korean forsythia, Dilatata lilac, Lilytree, Lily magnolia, and Prunus yedoensis) were analyzed using headspace extraction coupled to gas chromatography-mass spectrometry (HS-GC-MS) to study the aromatic profiles and fragrance compounds of each sample group. Various types of compounds associated with the aroma profiles were detected, including saturated alcohols and aldehydes (ethanol, 1-hexanol, and nonanal), terpenes (limonene, pinene, and ocimene), and aromatic compounds (benzyl alcohol, benzaldehyde). The different contribution of these compounds for each floral type was visualized using statistical tools and classification models based on principal component analysis with high reliability (R² = 0.824, Q² = 0.616). These results showed that HS-GC-MS with statistical analysis is a powerful method to characterize the volatile aromatic profile of biological specimens.

• Journal of Applied Biological Chemistry
• /
• 제64권2호
• /
• pp.141-151
• /
• 2021

Insects affect crop harvest yield and quality, making plant response mechanisms to insect herbivores a heavily studied topic. However, analysis of plant responses to honeybees is rare. In this study, comprehensive metabolic profiling of Arabidopsis thaliana exposed to honeybees was performed to investigate which metabolites were changed by the insect. A total of 85 metabolites-including chlorophylls, carotenoids, glucosinolates, policosanols, tocopherols, phytosterols, β-amyrin, amino acids, organic acids, sugars, and starch-were identified using high performance liquid chromatography, gas chromatography-mass spectrometry, and gas chromatography-time-of-flight mass spectrometry. The metabolite profiling analysis of Arabidopsis exposed to honeybees showed higher levels of stress-related metabolites. The levels of glucosinolates (glucoraphanin, 4-methoxyglucobrassicin), policosanols (eicosanol, docosanol, tricosanol, tetracosanol), tocopherols (β-tocopherol, γ-tocopherol), putrescine, lysine, and sugars (arabinose, fructose, glucose, mannitol, mannose, raffinose) in Arabidopsis exposed to honeybees were higher than those in unexposed Arabidopsis. Glucosinolates act as defensive compounds against herbivores; policosanols are components of plant waxes; tocopherols act as an antioxidant; and putrescine, lysine, and sugars contribute to stress regulation. Our results suggest that Arabidopsis perceives honeybees as a stress and changes its metabolites to overcome the stress. This is the first step to determining how Arabidopsis reacts to exposure to honeybees.

• 대한임상독성학회지
• /
• 제15권2호
• /
• pp.101-106
• /
• 2017

Purpose: This study examined the patterns of drugs, poisons, and chemicals detected in autopsy samples performed in the Seoul Institute and other regional forensic offices of the National Forensic Service (NFS) between 2014 and 2016. Methods: The investigation carried out using the laboratory information management system. Forensic toxicological identification and quantitation were performed in autopsy samples, including heart blood, peripheral blood, liver, kidney, vitreous humor and etc. Gas chromatography/mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to analyze the drugs and poisons. Results: Forensic autopsies were performed on 9,674 cases in this period. Based on the autopsy reports, 699 cases (7.2%) were considered as unnatural deaths caused by fatal intoxication. The number of male deaths was higher than that of female deaths, with the age of 50-59 being the most common age group. Conclusion: Drugs comprised the largest number of deaths due to poison, followed by alcohol, agrochemicals, drug with alcohol, carbon monoxide, and cyanide, in that order. Zolpidem was the most frequently used drug in all drug-related intoxication cases.

• 약학회지
• /
• 제36권3호
• /
• pp.230-240
• /
• 1992

The metabolic profile of doxylamine, N,N-dimethyl-2-[1-phenyl-1-(2-pyridinyl)ethoxy] ethanamine, was determined in the human urine. The free fractions of extracts were obtained without hydrolysis, and the conjugated fractions of extracts were obtained with enzyme hydrolysis using ${\beta}-glucuronidase/arylsulfatase$ from Helix pomatia. The mixture of acetic anhydride/pyridine (10 : 1, v : v) was used to derivatize the urinary extracts and then analyzed by gas chromatography and mass selective detector. N-desmethyldoxylamine, doxylamine carboxylic acid, desaminohydroxydoxylamine, N, N-didesmethyldoxylamine, N-acetyl conjugates of N-desmethyl and N, N-didesmethyldoxylamine, quarternary ammonium N-glucuronide of doxylamine, N-desmethyldoxylamine N-glucuronide and unchanged doxylamine were detected in the human urine obtained after oral treatment with doxylamine succinate. $N-methyl-{\alpha}-hydroxy-2-[1-phenyl-1-(2-pyridinyl)$ ethoxy] ethanamine, which can be a key intermediate of this metabolism, was tentatively identified by the interpretation of its mass spectrum. In this study, we proposed the metabolic pathway of doxylamine in the human on the basis of our data of the identified metabolites of doxylamine.

• 분석과학
• /
• 제20권4호
• /
• pp.315-322
• /
• 2007

본 연구는 1명의 건강한 성인남자로부터 pseudoephedrine과 dextromethorphan 복합제제 약물의 복용 후 24시간동안 배설된 소변을 채취하여 이들 혼합약물의 대사과정과 배설에 관하여 연구를 수행 하였다. 소변 중에 약물과 대사체의 검출을 위하여 가수분해 및 추출과정을 거쳐 MSTFA와 MBTFA를 사용하여 유도체 반응 후 GC-MS로 동시 분석을 수행하였다. 각 대사체는 질량스펙트럼의 해석을 통하여 구조가 규명되었으며, 시간에 따른 모 약물과 대사체의 배설율을 조사하였으며, 본 실험결과로부터 pseudoephedrine과 dextromethorphan의 체내 대사경로를 제안하였다.

• Journal of Microbiology and Biotechnology
• /
• 제28권3호
• /
• pp.473-481
• /
• 2018

Owing to its high protein secretion capacity, simple nutritional requirements, and GRAS (generally regarded as safe) status, Bacillus licheniformis is widely used as a host for the industrial production of enzymes, antibiotics, and peptides. However, as compared with its close relative Bacillus subtilis, little is known about the physiology and stress responses of B. licheniformis. To explore its temperature-stress metabolome, B. licheniformis strains ATCC 14580 and B186, with respective optimal growth temperatures of $42^{\circ}C$ and $50^{\circ}C$, were cultured at $42^{\circ}C$, $50^{\circ}C$, and $60^{\circ}C$ and their corresponding metabolic profiles were determined by gas chromatography/mass spectrometry and multivariate statistical analyses. It was found that with increased growth temperatures, the two B. licheniformis strains displayed elevated cellular levels of proline, glutamate, lysine, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, and octadecanoic acid, and decreased levels of glutamine and octadecenoic acid. Regulation of amino acid and fatty acid metabolism is likely to be associated with the evolution of protective biochemical mechanisms of B. licheniformis. Our results will help to optimize the industrial use of B. licheniformis and other important Bacillus species.