• Journal of Pharmaceutical Investigation
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• 제41권5호
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• pp.309-315
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• 2011

A sensitive and specific liquid chromatographic method coupled with tandem mass spectrometry (LC-MS/MS) was developed for the analysis of ambroxol (active moiety of acebrophylline). After acetonitrile precipitation of proteins from plasma samples, ambroxol and the domperidone (internal standard, IS) were eluted on a C18 column. The isocratic mobile phase was consisted of 10 mM ammonium acetate and methanol (10 : 90, v/v), with flow rate at 0.2 mL/min. A tandem mass spectrometer, as detector, was used for quantitative analysis in positive mode by a multiple reaction monitoring mode to monitor the m/z 379.2${\rightarrow}$264.0 and the m/z 426.2${\rightarrow}$175.1 transitions for ambroxol and the IS, respectively. Twenty four healthy Korean male subjects received two capsules (100 mg ${\times}$ 2) of either the test or the reference formulation of acebrophylline HCl in a 2 ${\times}$ 2 crossover study, this was followed by a 1week washout period between either formulation. $AUC_{0-t}$ (the area under the plasma concentration-time curve) was calculated by the linear trapezoidal rule. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. The 90% confidence intervals for the log transformed data were acceptable range of log 0.8 to log 1.25 (e.g., log 0.8964 - log 0.9910 for $AUC_{0-t}$ log 0.8690 - log 1.0750 for $C_{max}$). The major parameters, $AUC_{0-t}$ and $C_{max}$ met the criteria of Korea Food and Drug Administration for bioequivalence indicating that Acephyll$^{(R)}$ capsule (test) is bioequivalent to Surfolase$^{(R)}$ capsule (reference).

• Mass Spectrometry Letters
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• 제13권4호
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• pp.158-165
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• 2022

Many therapeutic class drugs such as beta-blocker, corticosteroids, NSAIDs, etc are prohibited substances in the horse racing industry. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology makes it possible to isolate drugs from interference, enables various drug analyses in complex biological samples due to its sensitive sensitivity, and has been successfully applied to doping control. In this paper, we describe a rapid and sensitive method based on solid-phase extraction (SPE) using solid phase cartridge and LC-MS/MS to screen for different class's 35 drug targets in equine plasma. Plasma samples were pretreated by SPE with the NEXUS cartridge consisted non-polar carbon resin and minimum buffer solvent. Chromatographic separation of the analytes was performed on ACQUITY HSS C18 column (2.1 × 150 mm, 1.8 ㎛). The elution gradient was conducted with 5 mM ammonium formate (pH 3.0) in distilled water and 0.1% formic acid in acetonitrile at a flow rate of 0.25 mL/min. The selected reaction monitoring (SRM) mode was used for drug screening with multiple transitions in the positive ionization mode. The specificity, limit of detection, recovery, and stability was evaluated for validation. The method was found to be sensitive and reproducible for drug screening. The method was applied to plasma sample analysis for the proficiency test from the Association of Racing Chemist.

• Mass Spectrometry Letters
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• 제2권1호
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• pp.20-23
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• 2011

The purpose of this study is to investigate the in vitro metabolism of hesperetin, a bioflavonoid. Hesperetin was incubated with rat liver microsomes in the presence of NADPH and UDP-glucuronic acid for 30 min. The reaction mixture was analyzed by liquid chromatography-ion trap mass spectrometer and the chemical structures of hesperetin metabolites were characterzed based on their MS/MS spectra. As a result, a total of five metabolites were detected in rat liver microsomes. The metabolites were identified as a de-methylated metabolite (eriodictyol), two hesperetin glucuronides, and two eriodictyol glucuronides.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4415-4418
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• 2011

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3284-3288
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• 2013

This paper describes first development and validation of pentafluorophenylprophyl ligand-based liquid chromatography coupled to tandem mass spectrometry (PFPLC-MS/MS) method to determine metformin, a highly polar compound, in human plasma. Metformin and Phenformin (internal standard) were extracted from human plasma 50 ${\mu}L$ with a single-step protein precipitation. The chromatographic separation was performed using a linear gradient elution of mobile phase involving 5.0 mM ammonium formate solution with 0.1% formic acid (A) and acetonitrile (B) over 3.0 min of run time on a Phenomenex Luna PFP column. The detection was performed using a triple-quadrupole tandem mass spectrometer (Waters Quattro micro) with electrospray ionization in the mode of positive ionization and multiple-reaction monitoring (MRM). The developed method was validated with 5.0 ng/mL of lower limit of quantification (LLOQ). The calibration curve was linear over 5-3000 ng/mL of the concentration range ($R^2$ > 0.99). The specificity, selectivity, carry-over effect, precision, accuracy and stability of the method met the acceptance criteria. The method developed in this study had had rapidness, simplicity and ruggedness. The reliable method was successfully applied to high throughput analysis of real samples for a practical purpose of a pharmacokinetic study.

• Archives of Pharmacal Research
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• 제27권12호
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• pp.1202-1206
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• 2004

A rapid, sensitive and selective liquid chromatography-tandem mass spectrometric (LC-MS/ MS) method for the determination of lithospermic acid B (LSB) in rat serum was developed. LSB and internal standard, 7-hydroxy-3-phenyl-chromen-4-one (HPC) were extracted from rat serum with methyl-tert-butyl ether at acidic pH and analyzed on a Luna $C_8$ column with the mobile phase of acetonitrile-ammonium formate (10 mM, pH 6.5) (50:50, v/v). The analytes were detected using a negative electrospray ionization tandem mass spectrometry in the multiple- reaction-monitoring mode. The standard curve was linear $(r^2 = 0.997)$ over the concentration range of 10.0-500 ng/mL. The coefficient of variation and relative error for intra- and interassay at three QC levels were 1.1~6.2% and -10.3~-2.7%, respectively. The recovery of LSB from serum sample ranged from 73.2 to 79.5%, with that of HPC (internal standard) being 75.1 %. The lower limit of quantification for LSB was 10 ng/mL using 50 ${\mu}L$ of serum sample.

• 분석과학
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• 제30권4호
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• pp.194-204
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• 2017

Direct injection (DI) and solid phase extraction (SPE) methods for the simultaneous determination of pendimethalin (PDM) and dinoseb (DNS) in environmental water have been optimized using the ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. The limits of quantification (LOQs) of PDM and DNS were $0.01{\mu}g/L$ using the DI method and $0.0001-0.0002{\mu}g/L$ using the SPE method. The precision by SPE UPLC-MS/MS was less than 11 % for intra-day and inter-day analyses. When the proposed SPE method was used to analyze two analytes in environmental water, PDM was detected in a concentration range of $0.0002-0.011{\mu}g/L$ in 31 samples of the 114 surface water samples, and DNS was detected in a concentration range of $0.0005-0.045{\mu}g/L$ in 17 samples of the 114 surface water samples analyzed. When the DI method was used to analyze target compounds in the same samples, the detected concentrations of the two analytes were within 21% in samples with concentrations above $0.01{\mu}g/L$. The DI UPLC-MS/MS method can thus be used for the routine monitoring of PDM and DNS in environmental water, and the SPE LC-MS/MS method can be used for the determination of the ultra-trace PDM and DNS residues in environmental water.

• 분석과학
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• 제28권5호
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• pp.317-322
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• 2015

토양 중 음이온 바이오사이드인 chlorite, chlorate, cyanuric acid와 sodium dodecylbenzenesulfonate (Na-DBS)의 liquid chromatography-tandem mass spectrometry (LC-MS/MS) 동시 분석방법을 개발하였다. Chlorite와 chlorate는 물로 추출하였으며, cyanuric acid와 Na-DBS는 0.25 mM ammonium formate를 함유한 20 mM formic acid와 acetonitrile (1:1) 이동상을 이용하여 추출하였다. 추출물은 필터 후 직접 LC-MS/MS로 주입하였다. 분석물질이 검출되지 않는 토양에 각 성분들을 첨가한 후 정도관리를 실시한 결과 검출한계는 chlorite 0.04 mg/kg, chlorate 0.04 mg/kg, cyanuric acid 0.27 mg/kg 그리고 Na-DBS의 경우는 0.05 mg/kg 이었다. 이 방법을 사용하여 우리나라 AI로 소독제를 많이 사용한 장소 40개 지역과 사용하지 않은 지역 10개 대조 지역의 토양을 분석한 결과 대조지역을 포함한 모든 조사지역에서 네 가지 음이온 모두 검출되지 않았다.

• 대한유전성대사질환학회지
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• 제15권2호
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• pp.59-64
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• 2015

사람의 신체내에서 주로 존재하는 lactate는 L-lactate로서 몇몇 선천성대사이상과 관련하여 증가된다. 최근 2형 당뇨병(type 2 diabetes)과 만성적인 염증성 위장질환(inflammatory bowel disease)과 관련하여 증가되는 D-lactate를 L-lactate와 분리해야 하는 요구도가 높아졌다. 이에 액체크로마토그래프-탠덤질량 분석기를 사용하여 소변 내 D-, L-lactate를 분리하는 방법을 확립하였으며, 분석시간과 정밀성, 정확성, 특이성 등에서 신뢰성 있는 방법임을 확인하였다.

• Food Science and Biotechnology
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• 제18권6호
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• pp.1470-1475
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• 2009

The seed coat of the black soybean contains 3 main anthocyanins such as delphinidin-3-O-$\beta$-glucoside, cyanidin-3-O-$\beta$-glucoside, and petunidin-3-O-$\beta$-glucoside. As a part of our effort on discovering and breeding new black soybean cultivars which possesses specific anthocyanin component rich, we determined the anthocyanin profiles of the 2 cultivars recently developed soybean cv. Gaechuck #1 and cv. Gyeongsang #1, using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and compared their content and identity with those of previously known 10 cultivar controls. The Cosmosil-$5C_{18}$-AR-II column were selected for the analysis because of the best peak separation. The column temperature was set up at $35^{\circ}C$. The mobile phase consisting of water containing 0.5%(v/v) formic acid and methanol gave good separation between the 3 anthocyanin analytes and internal standard (quercetin 3-O-$\beta$-rutinoside) and peaks with suppressed tail. The MS/MS spectra of each individual anthocyanin standard were detected in positive electron spray ionization (ESI) modes. It was disclosed that the anthocyanin contents of the soybean cv. Gaechuck#1 and cv. Gyeongsang#1 are roughly higher than those of the 10 controls.