• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.61-66
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• 2009

An analytical method based on solid-phase extraction and gas chromatography / mass spectrometry has been developed for measurement of acaricides (amitraz, bromopropylate, coumaphos, cymiazole, and tetradifon) in honey sample. In the stability test of acaricides in honey, amitraz underwent a rapid degradation into 2,4-dimethylaniline (DMA), 2,4-dimethylphenylformamide (DMPF), and N-(2,4-dimethylphenyl)-N'-methylformamidine (DMPMF), whileas other acaricides were found to be stable even for over three months. Extraction of five acaricides from 5g of honey sample was carried out by liquid-liquid extraction using 20mL of ethylacetate. For purification, Florisil-SPE cartridge with elution of 5mL of n-hexane/ acetone (55:45, v/v) was found to remove interferences effectively. Quantification was performed using gas chromatography / mass spectrometry in the selected ion monitoring mode. Spiking experiments were carried out to determine the recovery, precision, and limits of detection (LODs) of the method. The overall recovery values from honey spiked at 0.02 and 0.20 ${\mu}g/g$ levels, respectively, were found to be greater than 75% for all acaricides. The method detection limits for acaricides were ranged from 0.1 to 3 ppb. The developed method in this study was applied for the monitoring of acaricides in honey products collected from urban markets in Korea.

• 한국대기환경학회지
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• 제25권5호
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• pp.420-431
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• 2009

Characteristics and advantages of the thermal desorption-comprehensive two dimensional gas chromatography-time of flight mass spectrometry (TD-GCxGC-TOFMS) were discussed and the organic compound's analysis result was shown for the ambient $PM_{2.5}$ sample collected in Seoul, Korea. Over 10,000 individual organic compounds were separated from about $70{\mu}g$ of aerosols in a single procedure with no sample pre-treatment. Among them, around 300 compounds were identified and classified based on the mass fragmentation patterns and GCxGC retention times. Several aliphatic compounds groups such as alkanes, alkenes, cycloalkanes, alkanoic acids, and alkan-2-ones were identified as well as 72 PAH compounds including alkyl substituted compounds and 8 hopanes. In Seoul aerosol, numerous oxidized aromatic compounds including major components of secondary organic aerosols were observed. The inventory of organic compounds in $PM_{2.5}$ of Seoul, Korea suggested that organic aerosol were constituted by the compounds of primary source emission as well as the formation of secondary organic aerosols.

• 분석과학
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• 제13권5호
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• pp.666-674
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• 2000

본 연구는 기체크로마토그래피-질량분석법을 이용한 생물시료 중 polybrominated biphenyls(PBBs)의 분석법을 설명하였다. 생물 시료 중 PBB류는 40mL 아세톤과 80mL의 헥산 혼합용매에서 초음파추출기 20분간 교반하여 추출하였다. 추출액 중 존재하는 지질성분은 농축 황산용액으로 분해한 후 PBB류는 Florisil 컬럼으로 정제하였다. PBB류를 정량분석하기 위하여 정제액은 GC/MS-selected ion monitoring 방법에 의해 분석하였다. 본 실험 조건하에서 전반적인 PBB류의 추출율은 77-111%로 나타났다.

• Archives of Pharmacal Research
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• 제23권4호
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• pp.374-380
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• 2000

Propentofylline (PPF, 3-methyl-1-(5-oxohexyl)-7-propylxanthine) has been reported to be a compound for treatment of both vascular dementia and dementia of the Alzheimer type. The short half-life (about 15 min) of PPF at the terminal elimination phase and poor bioavailability after oral administration of PPF to rabbits (Kim et al., 1992) suggest in part that this drug takes the extensive first-pass metabolism in the liver. In addition, the metabolic pathway for PPF remains unclear. The objective of this experiment is to identify urinary metabolites of PPF in rats. For the identification of the metabolites, rat urine was collected after oral administration of 100${m}g/kg$ PPF. PPF metabolite, 3-methyl-1-(5-hydroxyhexyl)-7-propylxanthine, was synthesized and confirmed by gas chromatography/mass spectroscopy (GC/MS) and $^1H$ nuclear magnetic resonance spectroscopy. The urinary metabolites of PPF were extracted with diethyl ether and identified by electron impact and chemical ionization GC/MS. One urinary metabolite was confirmed to be 3-methyl-1-(5-hydroxyhexyl)-7-propylxanthine by synthesized authentic compound. Several metabolites of monohydroxy- and dihydroxy-PPF were identified based on mass fragmentation of both intact and trimethylsilylated derivatives of PPF metabolites and the novel structure of these metabolites is suggested based on mass spectra.

• Mass Spectrometry Letters
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• 제1권1호
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• pp.29-32
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• 2010

Cross reacting antibodies can cause an overestimation of the results of immunoassays. Therefore, alternative methods are needed for the accurate quantification of steroids. Gas chromatography combined with isotope-dilution mass spectrometry (GC-IDMS) is developed to quantify urinary active androgens, testosterone, epitestosterone and dihydrotestosterone, which are clinically relevant androgens to both hair-loss and prostate diseases. The method devised involves enzymatic hydrolysis with $\beta$-glucuronidase, solid-phase extraction, liquid-liquid extraction using methyl tert-butyl ether and subsequent conversion to pentafluorophenyldimethylsilyl-trimethylsilyl (flophemesyl-TMS) derivatives for sensitive and selective analysis in selected-ion monitoring mode. Flophemesyl-TMS derivatization not only eliminates matrix interference but also has a good peak resolution within a 6 min-run. A selective and sensitive GC technique with flophemesyl-TMS derivatives also allows accurate quantitative analysis of three active androgens when combined with IDMS. The limit of quantification of the three analytes was <50 pg/mL, and extraction recoveries ranged from 91.9 to 102.1%. The precision and accuracy were 1.2~6.5% and 89.0~106.7%, respectively. This GC-IDMS method can be useful for evaluating the drug efficacy and monitoring the biological processes responsible for male-pattern baldness and prostate diseases.

• Mass Spectrometry Letters
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• 제12권2호
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• pp.31-40
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• 2021

Probable human carcinogenic compounds nitrosamines, have been detected as by-product impurities in sartan pharmaceuticals in recent years which has drawn worries for medication safety. To provide a sensitive and effective method for the quality control of sartan pharmaceuticals, this study established a feasible gas chromatography-tandem mass spectrometry (GC-MS/MS) method for simultaneous determination of 13 nitrosamines. The target analytes were separated on a DB-WAX Ultra Inert column (30 m × 0.25 mm; i.d., 0.25 ㎛) and were then subjected to electron impact ionization in multiple reaction monitoring mode. The established method was validated and further employed to analyze authentic samples. Limits of detection (LODs) and limits of quantification (LOQs) of the 13 nitrosamines were 15-250 ng/g and 50-250 ng/g, respectively, which also exhibited intra-day and inter-day accuracies of 91.4-104.8%, thereby satisfying validation criteria. Five nitrosamines, viz., N-nitrosodiethylamine, N-nitrosodimethylamine, N-nitrosodiphenylamine, N-nitrosomorpholine, and N-nitrosopiperidine were detected at concentrations above their LODs in 68 positive samples out of 594 authentic samples from seven sartans.

• 한국식품위생안전성학회지
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• 제8권1호
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• pp.9-15
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• 1993

어패류를 포함한 식용 육류중에 잔류하는 항생물질 및 항균성물질을 검출하기 위하여, 분석기기로서 Gas chromatography/ Mass spectrometry(GC/MS)를 사용한 동시분석법을 개발하였다. 여러 항생.항균제중에서 penicillin G, chloramphenicol, thiamphenicol을 중심으로 간단한 전처리과정과 유도체화를 하여 GC/MS 분석을 시행하였다. 전처리 과정을 요약하면 pH 4.0의 0.01 M EDTA-2Na McIlvaine buffer로의 추출, n-hexane으로의 탈지, Bond-Elute $C_{18}$ cartridge에 흡착된 물질의 0.01 M-methnolic oxalic acid로의 용출 그리고 건조 후 유도체화의 순으로 되어 있다. 본 방법에 의한 1 ppm spike시의 회수율은 penicillin G, chloramphenicol, thiamphenicol 각각 63.5%, 76.3%, 84.7%이었고, 검출한계는 각각 시료 g당 0.6, 0.085, $0.084\;\mu\textrm{g}$이었다. 또한 GC/MS 확인과정에서 실제 잔류농도가 1 ppm 이상이면 full scan spectrum으로 확인이 가능하였다. 이와 같은 GC/MS에 의한 잔류물질의 정량 및 확인시험은 앞의 미생물학적 방법의 복원은 물론 식품의 안전성 재고 및 규제독성의 측면에서도 매우 뜻 있는 연구라 하겠다.

• Mass Spectrometry Letters
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• 제12권4호
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• pp.137-145
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• 2021

Herein we report multiple ion mobility (IM) peaks in electrospray ionization IM mass spectrometry (ESI-IM-MS) produced by glutamine residue in peptide. The mobility features of 147 peptides were investigated using ESI-IM-MS combined with liquid chromatography. Of these peptides, 66 presented multiple IM peaks, and analysis of their sequence using collision induced dissociation (CID) revealed that glutamine (Gln), as well as proline (Pro), plays a critical role in generating multiple IM peaks. Mutant-based investigations using Gln-containing peptides indicate that the side chain of Gln promotes intermolecular interactions, inducing multiple structures of the peptide ions in the gas phase. Consequently, the present study demonstrates that the distinct ion mobility signatures identified herein can potentially be used to characterize glutamine-containing peptide ions.

• 대한화학회지
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• 제21권3호
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• pp.193-203
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• 1977

오이, 수박, 수세미, 박, 하늘수박의 다섯가지 박과식물 종자유에서 세가지 스테롤 플랙숀을 박층 크로마토그래피로 나누고 각 플랙숀의 조성을 가스크로와 가스크로에 연결된 질량분석법으로 밝혔다. 이중 4-데스메틸스테롤 플랙숀에서 ${\alpha}$-Spinasterol, ${\Delta}^{7,22,25}$-stigmastatrienol 및 ${\Delta}^{7,25}$-stigmastadienol를 단리(單離)하여 IR, NMR 및 질량분석법으로 동정(同定)하였다.

• Applied Biological Chemistry
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• 제21권1호
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• pp.11-15
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• 1978

측쇠 아미노산의 대사의 장해를 받음으로 생기는 maple syrup disease환자의 혈액에서 alloisoleucine를 GLC와 질량분석기를 사용하여 동정하였다.