• 분석과학
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• 제16권6호
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• pp.488-498
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• 2003

LC/MS/MS를 이용하여 발기부전 (impotence) 치료제인 sildenafil 및 유사체인 homosildenafil, vardenafil, tadalafil을 분석하는 방법을 확립하였다. 이온화 방법으로는 electrospray ionization (ESI)와 atmospheric pressure chemical ionization (APCI) 방법을 사용하였으며 최대 감도와 재현성을 나타내는 조건을 찾기 위하여 여러 가지 파라미터를 변화시켜서 비교하였다. MRM (multiple reaction monitoring)을 위한 적절한 생성이온 (product ion)을 얻기 위하여 ESI 방법에서는 capillary voltage, cone voltage, extractor, entrance, RF lens를 변화시켰으나 전구이온 (precursor ion)을 제외한 뚜렸한 토막이온 (fragment ion)은 생성되지 않았다. 한편, APCI 방법의 경우 entrance, collision energy, exit, corona voltage, cone voltage, extractor, RF lens, cone gas, desolvation gas를 변화시켰을 때 다른 파라미터들의 변화에 따른 전구이온을 제외한 product ion 생성 패턴의 변화는 감지되지 않고 단지 RF lens 조건의 변화에서 precursor ion을 비롯한 토막이온들의 생성과 더불어 S/N의 증가로 인한 검출 한계의 향상이 나타났다. HPLC에서의 최적 분리 조건과 질량 분석기에서 최대 감도를 나타내는 이동상 조건도 조사되었는데 10 mM ammonium formate (pH 4.8):acetonitrile=70:30 의 등용매 용리조건이 좋은 감도를 나타내었으며, 최적의 방법인 ESI-MRM 방법에서 검출한계 (S/N>5)는 sildenafil은 $0.10{\mu}g/mL$, homosildenafil은 $0.025{\mu}g/mL$, vardenafil은 $0.025{\mu}g/mL$ 그리고 tadalafil은 $0.25{\mu}g/mL$이었다.

• 한국물환경학회지
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• 제29권3호
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• pp.409-419
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• 2013

In this study, the analytical method for 27 residual pharmaceuticals in raw water was developed. Online sample preconcentration/extraction and analysis with high resolution Orbitrap mass spectrometry (LC-ESI/Orbitrap MS) were performed. The calibration curves showed good linearities (above $r^2$ = 0.998) in the range of 5 ~ 1,000 ng/L. The method detection limit and the limit of quantification were 1.1 ~ 10.0 ng/L and 3.4 ~ 31.7 ng/L, respectively. Recoveries of the target compounds were between 70.1% and 115.8% (except cefadroxil, cefradine, vancomycin, and iopromide (50.2 ~ 67.0%)). The optimized analytical method can be useful to determine the residual pharmaceuticals in raw water.

• Mass Spectrometry Letters
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• 제2권3호
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• pp.65-68
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• 2011

The effects of column length and particle size on the efficiency of separation and characterization of phospholipids (PLs) are investigated using nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry (nLC-ESI-MS-MS). Since PLs are associated with cell proliferation, apoptosis, and signal transduction, it is of increasing interests in lipidomics to establish reliable analytical methods for the qualitative and quantitative profiling of PLs related to biomarker development in adult diseases. Due to the complexity of PLs, the preliminary separation of PLs is necessary prior to MS analysis. In this study, length of capillary column and the particle size of reversed phase ($C_{18}$) packing materials are varied to find a reliable condition for the high speed and high resolution separation using 8 PL standard mixtures. From experiments, it was found that a capillary column of nLC-ESI-MS-MS analysis for PL mixtures can be minimized to a 5 cm long pulled tip column packed with 3 ${\mu}m$ $C_{18}$ particles without losing resolution.

• 분석과학
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• 제21권3호
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• pp.191-200
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• 2008

의약물질(PPCPs)은 수질 환경 시료에서 새로운 오염물질로 대두되고 있다. 본 연구에서는 LC/ESI-MS/MS를 이용하여 환경 수질 시료로부터 7 종(2-퀴노사린카르복시산, 아세틸살리실산, 디클로페낙-소듐, 나프록센, 이부프로펜, 메페남산, 탈니플루메이트)의 산성의약물질을 동시 분석하는 방법을 비교하여 개선하였으며 폐수처리장의 유입수 및 방류수 그리고 연장선상의 하천수의 오염도를 측정하였다. LC/ESI-MS/MS 분석을 위해서 MCX (Mixed Cation eXchange) 카트리지와 HLB (Hydrophilic-Lipophilic Balance) 카트리지를 연결하는 텐뎀 고체상 추출법과 MCX 카트리지만을 사용하는 고체상 추출법을 이용하여 효과적인 시료 정제 및 추출을 수행하였다. 검출한계(LODs)와 방법검출한계(MDLs)는 각각 0.05~1.50 pg/mL, 0.17~4.90 pg/mL 범위를나타내었다. 시료중 1.0 ng/mL 농도(n=3)에서절대회수율은 81.9%~116.3%를 나타내었다. 수질 환경 시료에서 수 pg/mL~ng/mL의 농도로 산성의약물질이 측정되었다.

• Mass Spectrometry Letters
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• 제5권1호
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• pp.1-11
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• 2014

Lipids play important roles in biological systems; they store energy, play a structural role in the cell membrane, and are involved in cell growth, signal transduction, and apoptosis. Phospholipids (PLs) in particular have received attention in the medical and lipidomics research fields because of their involvement in human diseases such as diabetes, obesity, atherosclerosis, and many cancers associated with lipid metabolic disorders. Here I review experimental strategies for PL analysis based on nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry (nLC-ESI-MSn). In particular, discussed are lipid extraction methods, nanoflow LC separation of PLs, effect of ionization modifiers on the ESI of PLs, influence of chain lengths and unsaturation degree of acyl chains of PLs on MS intensity, structural determination of the molecular structure of PLs and their oxidized products, and quantitative profiling of PLs from biological samples such as tissue, urine, and plasma in relation to cancer and coronary artery disease.

• Mass Spectrometry Letters
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• 제8권4호
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• pp.90-97
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• 2017

Androgenic anabolic steroids (AASs) are synthetic derivatives of testosterone with a common structure containing cyclopentanoperhydrophenanthrene nucleus. Their use enhances the muscle building capacity and is beneficial during performance. The AASs are one of the most abused group of substances in horse doping. Liquid chromatography tandem mass spectrometry ($LC/MS^n$) has been successfully applied to the detection of anabolic steroids in biological samples. However, the saturated hydroxysteroids viz: nandrolone, $5{\alpha}-estrane-3{\beta}$, $17{\alpha}-diol$ exhibit lower detection responses in electrospray ionisation (ESI) because of their poor ionisation efficiency. To overcome this limitation pre-column chemical derivatization has been introduced to enhance their detection responses in $LC-ESI-MS^n$ analysis. The aim of present study was to develop a sensitive method for identification and confirmation of nandrolone and its metabolite in horse urine incorporating pre-column derivatization using picolinic acid. The method consists of extraction of targeted steroid conjugates by solid phase extraction (SPE). The eluted steroid conjugates were hydrolysed by methanolysis and free steroids were recovered with liquid-liquid extraction. The resulting steroids were derivatized to form picolinoyl esters and identification was done using LC-ESI-MS/MS in positive ionization mode. The picolinated steroid adduct enhanced the detection levels in comparison to underivatized steroids.

• 생약학회지
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• 제44권4호
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• pp.350-361
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• 2013

Asarum sieboldii has been used for treatment of fever, pain, common cold, and chronic sinusitis in Korea. In this study, we performed quantification analysis of seven major constituents including aristolochic acid I, aristolochic acid II, ${\alpha}$-asarone, ${\beta}$-asarone, elemicin, methyl eugenol, and safrole in the 70% ethanol extract of Asarum sieboldii and its solvent fractions, n-hexane, ethylacetate, n-butanol, and water ones using a ultra-performance liquid chromatography-electrospray ionization-mass spectrometer(UPLC-ESI-MS) and gas chromatography-mass spectrometer(GC-MS). Regression equations of seven components were acquired with $r^2$ values >0.99. The values of limit of detection(LOD) and quantification(LOQ) were 0.1-3.9 ng/mL and 0.3-11.7 mg/mL, respectively. The amount of the seven compounds in Asarum sieboldii were not detected -143.66 mg/g. The established LC-MS/MS and GC-MS methods will be helpful to improve quality control of Asarum sieboldii.

• Journal of Microbiology and Biotechnology
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• 제20권6호
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• pp.959-967
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• 2010

Down syndrome (DS) is an abnormality of the 21st chromosome that commonly occurs in children born to older women. Thus, amniotic fluid (AF) is usually collected from such women for prenatal diagnosis. This study analyzed human AF supernatants (AFS) using a mass spectrometric (MS) approach to search for candidate biomarkers of a DS pregnancy. The AFS were collected from older pregnant women at weeks 16-18 of their gestation by amniocentesis for cytogenetic analysis. The AFS from the pregnancies carrying DS (n=4) or chromosomally normal (n=6) fetuses, as revealed by the cytogenetic analysis, were then subjected to global protein profiling based on liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Affinity chromatography was also applied prior to the LC-ESI-MS/MS to minimize the masking effect of highly abundant albumin and immunoglobulin and thereby increase the diversity of the identified proteins. As a result, at least 30 new AFS proteins were identified and 44 AFS proteins were found to be differentially expressed between the DS and normal cases, where 6 of the proteins were unique to the DS cases and 11 were unique to the chromosomally normal cases. In addition, in the DS cases, 19 AFS proteins were downregulated and 8 were upregulated to varying degrees. A Western blot analysis confirmed the LC-ESI-MS/MS data, indicating that the combined detection of apolipoprotein A-II (apoA-II) and alpha-fetoprotein (AFP) could be a potential tool for diagnosing DS cases.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2010년도 정기총회 및 춘계학술발표회
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• pp.18-18
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• 2010

Glucosinolates(GSLs) are major secondary products($\beta$-thioglucoside N-hydroxysulfates) containing sulfates that are found mainly in Cruciferae family such as cabbage, broccoli, radish, turnip, kale, mustard and rapeseed as the important crops in agronomic and economic aspects. Especially, isothiocyanates(ITCs) have been shown to inhibit carcinogenesis with regulation cancer cell development followed by regulating target enzymes, inducing cell cycle arrest and apoptosis against various human cancer cell lines. Total desulfo(DS)-GSLs of nine type in 210 Korean leaf mustard accessions were isolated and confirmed using electrospray ionization mass spectrometric(ESI-MS/MS) method and DS-GSLs powerful library maked from several reference data. The isolated individual DS-GSLs were identified by removed $\beta$-D-glucopyranose residue ($C_6H_{11}O_5$, MW 163) from MS/MS data. Among them sinigrin(41.7%), glucoiberverin(21.7%) and gluconasturtiin(12.6%) were major components, Especially, despite gluconapin was minor component, accession K046197-1 and K046197-2 showed higher content of 4.11 and 3.31 mg/g(DW), respectively. The total GSLs contents in 210 accessions were ranged from 5.3 to 23.2 mg/g(DW) with a mean value of 13.0 mg/g(DW). As a result of principal component analysis(PCA), the individual GSLs loading plots were composed of three groups and components belonged to each group showed correlationship in quantitative pattern.

• 분석과학
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• 제22권4호
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• pp.326-335
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• 2009

계란 중에 잔류하는 6 종의 글루코코티코이드 약물을 극미량으로 분석하는 방법이 개발되었다. 동시분석을 위한 시료 추출방법과 정제방법을 확립하였으며 액체 크로마토그래프와 질량분석기의 최적화 조건을 확립하였으며, 글루코코티코이드를 분석하기 위해서는 5 g의 계란에 초산 완충용액을 사용하여 시료의 pH를 5.2로 조절한 후 효소 가수분해를 위해 Helilx pomatia를 사용하였다. 혼합물을 원심분리하여 20 mL n-헥산으로 두 번 추출하였다. 다시 HLB 카트리지에서 메탄올에 의한 추출이 이루어진 후 연속해서 실리카 카트리지에서 메탄올/에틸아세테이트를 사용하여 정제하였다. 분석물질은 역상 HPLC/ESI-MS/MS로 분석하였으며 ESI는 음이온 모드를 사용하였다. 검정곡선의 상관계수는 0.99 이상을 나타내었고 검출한계는 $0.09-0.17{\mu}g/kg$ 이었으며 회수율은 55.7-69.8%이었다. 바탕 계란 중에서 실험된 유효성 검증방법에 근거하여 확립된 분석법은 계란 중 글루코코티코이드를 수 ${\mu}g/kg$ 농도까지 검출하는데 사용될 수 있을 것이다.