• 분석과학
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• 제31권1호
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• pp.39-46
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• 2018

온라인 고체상 추출을 이용한 LC/MS/MS를 사용하여 carbaryl과 유기인계 농약 7 종을 동시에 분석하는 방법을 확립하였다. 분석 대상농약은 carbaryl, diazinon, methyl-demeton, fenitrothion, malathion, parathion, phenthoate, EPN 등 8 종이다. 본 연구에서는 온라인 고체상 추출과 LC/MS/MS의 ESI positive mode로 전처리 없이 물 시료 $500{\mu}L$를 직접 주입하여 10분안에 분석하였다. 농약 8 종의 회수율은 86.8~100 % 였고, 정확도는 90.6~98.8 %로 90 %이상이었고, 정밀도는 1.3~5.2 %로 나타났으며 검출한계 및 정량한계는 각각 $0.05{\sim}0.28{\mu}g/L$, $0.16{\sim}0.89{\mu}g/L$ 였다. $0.5{\mu}g/L$에서 $8.0{\mu}g/L$까지 다섯 개의 농도로 검량선을 작성한 결과 모든 물질의 상관계수(r2)가 0.99이상을 나타냈다. 방법의 유효성 평가를 한 결과 모든 내용에서 적합하므로확립한 분석방법으로 수질 시료에서 농약을 조사한 결과 모두 검출되지 않았다.

• 분석과학
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• 제28권1호
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• pp.17-25
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• 2015

A rapid, sensitive and specific method was developed and validated using electrospray ionization (ESI) tandem mass spectrometry (LC-MS/MS) for determination of misoprostol acid in human plasma. Misoprostol $acid-d_5$ was used as in internal standard (IS). The analyte and IS were extracted by simple one step solid phase extraction (SPE). Linearity in plasma was obtained over the concentration range 10~3000 pg/mL and lower limit of quantification (LLOQ) was identifiable and reproducible at 10 pg/mL. The intra- and inter-day precision values were below 9% and the accuracy was ranged from 93.81% to 102.02% at all four quality control samples. The method was has been successfully applied for routine assay to support pharmacokinetic study of misoprostol acid in human plasma after an oral administration of 0.4 mg misoprostol.

• Bulletin of the Korean Chemical Society
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• 제35권4호
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• pp.1133-1138
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• 2014

Ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI- MS/MS) provides a high-speed method to screen a large number of samples for small molecules with specific properties. In this study, UPLC-ESI-MS/MS with multiple reaction monitoring (MRM) was employed to screen urinary phospholipid (PL) content for biomarkers of prostate cancer. From lists of urinary PLs structurally identified using nanoflow LC-ESI-MS/MS, 52 PL species were selected for quantitative analysis in urine samples between 22 cancer-free urologic patients as controls and 45 prostate cancer patients. Statistical treatment of data by receiver operating characteristic (ROC) analysis yielded 14 PL species that differed significantly in relative concentrations (area under curve (AUC) > 0.8) between the two groups. Among PLs present at higher levels in prostate cancer urine, phosphatidylcholines (PCs) and phosphatidylinositols (PIs) constituted the major head group PLs (3 PCs and 7 PIs). For technical reasons, PL species of low abundance may be underrepresented in data from UPLC-ESI-MS/MS performed in MRM mode. However, the proposed method enables the rapid screening of large numbers of plasma or urine samples in the search for biomarkers of human disease.

• Journal of Microbiology
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• 제45권4호
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• pp.326-332
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• 2007

In order to understand the functional role of CPRl in Saccharomyces cerevisiae KNU5377 with regard to its multi-tolerance characteristics against high temperatures, inorganic acids, and oxidative stress conditions, whole cellular proteins were analyzed via liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). This procedure was followed by two-dimensional (2-D) gel electrophoresis. Under menadione stress conditions, the 23 upregulated proteins were clearly identified only in the wild- type strain of KNU5377. Among the proteins, Sodl1p Tsa1p, Ahp1, Cpr1p, Cpr3, Ssb2p, and Hsp12p were identified as components of antioxidant systems or protein-folding related systems. The CPR1 protein could not be completely detected in the $cpr1{\Delta}$ mutant of KNU5377 and the other upregulated proteins in the wild-type strain evidenced a clear correlation with the results of immunoblot analysis. Moreover, a reduction in growth patterns (about 50%) could be observed in the $cpr1{\Delta}$ mutant, as compared with that of the wild-type strain under mild MD stress conditions. These results indicate that the upregulation of CPR1 may contribute to tolerance against MD as an inducer of oxidative stress.

• 생명과학회지
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• 제22권11호
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• pp.1456-1462
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• 2012

소라페닙은 멀티카이네즈 억제제로서 신세포암, 전이성 간세포암 환자의 치료에 효과가 입증된 경구용 항암제이다. 이 연구의 목적은 고속액체크로마토그래피 텐덤질량분석기법(LC/MS/MS)을 이용하여 사람 혈장 내 소라페닙의 농도를 측정하는 효율적인 방법을 개발하고 한국식품의약품안전청(KFDA) 기준에 따라 분석법을 검정하는 것이다. 혈장시료($100{\mu}l$)에 내부표준물질인 chlorantraniliprole을 첨가한 후 이소프로필알콜과 에틸아세테이트로 구성(1:4, v/v)된 0.1% 포름산 함유 추출용액을 혼합하였다. 원심분리 후 상층액을 취하여 원심감압농축하였다. 잔사를 이동상에 재용해하고 Waters사의 역상 XTerra$^{TM}$ C18 칼럼(입자크기 $3.5{\mu}m$)을 장착한 고속액체크로마토그래피 장치에 주입하였다. 액체크로마토그래피는 0.1% 포름산과 10 mM 암모늄 포메이트를 함유한 버퍼용액과 메탄올, 아세토나이트릴을 각각 1:6:3으로 혼합한 용액을 이동상으로 사용하였으며 5분 내에 측정을 완료하였다. 분석대상 물질들은 텐덤질량분석기에서 electrospray 양이온 이온화($ES^+$) 검출방식으로 확인하였으며 소라페닙은 'm/z 465.2 ${\rightarrow}$ 252.5', chlorantraniliprole은 'm/z 484.4 ${\rightarrow}$ 286.2'으로 구성한 multiple reaction monitoring 방법을 사용하였다. 검정 결과, 2-5,000 ng/ml의 농도 구간에서 양호한 직선성($r^2$ > 0.99)과 정확도(90.7-103.9%), 정밀도(10% 이하)를 나타내었다. 새롭게 개발된 LC/MS/MS을 이용한 사람 혈장 내 소라페닙의 농도 측정법은 KFDA 기준을 만족하였으며, 기존의 방법에 비해 민감도가 높은 방법이었다.

• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1216-1223
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• 2016

The aim of this study was to isolate antioxidant peptides from an enzymatic hydrolysate of Spirulina platensis. A novel antioxidant peptide was obtained by ultrafiltration, gel filtration chromatography, and reverse-phase high-performance liquid chromatography, with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay used to measure the antioxidant activity, and the sequence was determined to be Pro-Asn-Asn (343.15 Da) by electrospray ionization tandem mass spectrometry. This peptide was synthesized to confirm its antioxidant properties, and it exhibited 81.44 ± 0.43% DPPH scavenging activity at 100 μg/ml, which was similar to that of glutathione (82.63 ± 0.56%). Furthermore, the superoxide anion and hydroxyl free-radical scavenging activities and the SOD activity of the peptide were 47.84 ± 0.49%, 54.01 ± 0.82%, and 12.55 ± 0.75%, respectively, at 10 mg/ml. These results indicate that S. platensis is a good source of antioxidant peptides, and that its hydrolysate may have important applications in the pharmaceutical and food industries.

• Journal of Biomedical and Translational Research
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• 제19권4호
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• pp.130-139
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• 2018

This study aimed to analyze a high-performance liquid chromatography (HPLC) separation using a pentafluorophenyl column of parent drug hydroxychloroquine (HCQ) and its active metabolite, desethylhydroxchloroquine (DHCQ) applying to determine bioequivalence of two different formulations administered to patients. A rapid, simple, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for bioanalysis of HCQ and its metabolite DHCQ in human whole blood using deuterium derivative $hydroxychloroquine-D_4$ as an internal standard (IS). A triple-quadrupole mass spectrometer was operated using electrospray ionization in multiple reaction monitoring (MRM) mode. Sample preparation involves a two-step precipitation of protein techniques. The removed protein blood samples were chromatographed on a pentafluorophenyl (PFP) column ($50mm{\times}4.6mm$, $2.6{\mu}m$) with a mobile phase (ammonium formate solution containing dilute formic acid) in an isocratic mode at a flow rate of 0.45 mL/min. The standard curves were found to be linear in the range of 2 - 500 ng/mL for HCQ; 2 - 2,000 ng/mL for DHCQ in spite of lacking a highly sensitive MS spectrometry system. Results of intra- and inter-day precision and accuracy were within acceptable limits. A run time of 2.2 min for HCQ and 2.03 min for DHCQ in blood sample facilitated the analysis of more than 300 human whole blood samples per day. Taken together, we concluded that the assay developed herein represents a highly qualified technology for the quantification of HCQ in human whole blood for a parallel design bioequivalence study in a healthy male.

• 한국산업보건학회지
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• 제26권2호
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• pp.178-187
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• 2016

Objectives: Diisocyanates are a potent inducer of diseases of the airways, especially asthma. In this study, toluenediamine(TDA) and methylenedianiline(MDA) in urine were evaluated as biomarkers of exposure to tolunenediisocyanate(TDI) and methylenediphenyl diisocyanate(MDI), respectively. Methods: Workers exposed to TDI and MDI, as well as non-occupationally exposed subjects, were studied and pre- and post-shift urine samples were collected from 8 control subjects and 8 workers from a factory which manufactures polyurethane products for reducing noise and vibration in automobiles. Airborne TDI and MDI(n=8) were sampled on solvent-free glass filters impregnated with n-butylamine and detected by liquid chromatography atmospheric pressure ionization tandem mass spectrometry. Urinary TDA and MDA were detected as pentafluoropropionic acid anhydride(PFPA) derivatives by liquid chromatography electrospray ionization tandem mass spectrometry. Results: The median levels of urinary 2,6-TDA(p<0.001), 2,4-TDA(p=0.001), and MDA(p<0.001) of workers in post-shift samples were significantly higher than those of controls. The median levels of urinary 2,6-0TDA($0.63{\mu}g/g$ creatinine vs $0.34{\mu}g/g$ creatinine, p=0.017) and MDA($4.21{\mu}g/g$ creatinine vs $3.18{\mu}g/g$ creatinine, p=0.017) of workers in post-shift samples were significantly higher than those of the pre-shift samples. There were significant correlations between the urinary 2,6-TDA, 2,4-TDA, and MDA of workers in post-shift samples and the airborne 2,6-TDI(rho=0.952, p<0.001), 2,4-TDI(rho=0.833, p=0.001), and MDI(rho=0.952, p<0.001). Conclusions: These urinary diamines, metabolites of diisocyanates, in post-shift samples were useful biomarkers to assess occupational exposure to diisocyanates.

• 분석과학
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• 제24권2호
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• pp.78-84
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• 2011

본 연구에서는 양성 및/또는 음성 이온 방식으로 저에너지 충돌-유발 분해(CID)를 이용한 serine protease 저해제인 camostat 와 그것의 분해산물인 4-(4-guanidinobenzoyloxy)phenylacetic acid (GBPA)의 분해 패턴을 전자분무 소스가 있는 사중극자 텐덤 질량분석기(ESI-MS/MS)를 이용하여 최초로 조사하였다. Camostat의 양이온 CID 질량 스펙트럼 분석결과, 분자구조내 에스테르 결합을 이루는 카르보닐 기와 산소 원자사이의 단일 결합(C-O) 분해가 우선적으로 일어나고, guanidine 기의 초기 손실보다는 N,Ndimethylcarbamoylmethyl기의 초기 손실이 더 잘 일어난다는 것이 특징적으로 확인되었다. GBPA의 양이온 CID 스펙트럼의 경우는, 4-guanidinobenzoyloxy 기에 있는 카르보닐 기와 산소원자 사이의 초기 분해가 일어나서 m/z 145에서 가장 강도가 높은 피크를 만들었다. 반면에, GBPA의 음이온 스펙트럼은 m/z 312의 모분자 이온에서 $CO_2$와 NH=C=NH의 순차적인 중성 손실로 인하여 m/z 226의 가장 강도가 높은 피크가 특징적으로 생성되었다.

• 한국환경농학회지
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• 제35권3호
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• pp.166-174
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• 2016

농경지 토양에서 대상항생제 6종(amoxicillin, ampicillin, chlortetracycline, enrofloxacin, oxytetracycline, tetracycline을 아세트산 함유 아세토니트릴, Na₂Cit.5H₂O, Na₃Cit.2H₂O과 Na₂-EDTA로 추출 후 C₁₈으로 정제하여 LC-MS/MS로 분석하는 모니터링을 수행하였다. 그 중 2종의 항생제, chlortetracycline과 enrofloxacin이 국내 농경지 토양에서 검출되었다. 제안한 분석법은 토양 중 잔류 항생제 모니터링을 위한 빠르고 간편한 시험법이었고 다양한 활용이 가능할 것으로 보인다.