• Mass Spectrometry Letters
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• 제14권4호
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• pp.141-146
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• 2023

Liraglutide is a medication prescribed for the management of type 2 diabetes and chronic obesity. A simple, sensitive, and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantitative analysis of liraglutide in rat plasma. After a simple protein precipitation step, liraglutide was chromatographically separated using the ACQUITY Premier Peptide BEH C18 Column with mobile phases comprising 50% acetonitrile and 50% methanol, and water with 0.3% FA. Positive ion electrospray ionization in multiple reaction monitoring mode was used to achieve detection. Good linearity was observed in the 5-600 ng/mL concentration range (R² > 0.99). Liraglutide had intra- and inter-day precision values of 2.13%-9.86% and 4.14%-8.36%, respectively. The accuracy ranged from -2.36% to 2.58%. The recovery and matrix effect were within acceptable limits. This selective LC-MS/MS method was used to study the pharmacokinetic properties of liraglutide after subcutaneous administration in rats.

• 대한간호학회지
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• 제45권3호
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• pp.420-428
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• 2015

Purpose: Purpose was to explore associations between sleep duration and metabolic syndrome (MS) risks, and to determine factors associated with self-rated health (SRH) of adults with MS compared to other adults. Methods: This is a secondary data analysis based on the Fifth Korea National Health and Nutrition Examination Survey KNHANES V (N=12662). Study instruments included sleep duration, MS risk factors, SRH and health-related quality of life (HRQoL). Results: Mean age of participants was $43.68{\pm}12.26years$. Fifty-eight percent were women, and 18.3% were identified as having MS. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and SRH were significantly different according to sleep duration (p <.05) among all participants. In the non MS group, male gender, younger age (19~30 and 41~50 age brackets) upper income level, sufficient sleep duration, and high density lipoprotein (HDL) were positively associated with SRH, whereas, lower education levels (${\leq}$ middle school), glucose level, and waist circumference were negatively associated with SRH (p <.05). In the MS group, lower income, lower education levels (${\leq}$ middle school), glucose level, and waist circumference were negatively associated with SRH, whereas, having an occupation was positively associated with SRH (p <.05). Conclusion: Results suggest that tailored approaches are required for prevention and control of MS and sleep duration of each individual should be considered rather than applying standardized guidelines. However, as sleep quality was not included in the analysis, further investigations regarding influence of sleep quality on MS and SRH and controlling for other lifestyle and health behavior factors are required.

• 한국동물위생학회지
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• 제28권1호
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• pp.81-89
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• 2005

Recently, mass spectrometry coupled with liquid chromatography (LC/MS) has been a preferred technique for determination of organic compounds in complex matrixes. LC/MS provides a high degree sensitivity and specificity of the compounds of interest. The purpose of this study was to confirm analytical method of residual 6 benzimidazoles (thiabendazole, oxfendazole, mebendazole, albendazole, flubendazole and fenbendazole) in meat by LC/MS. Benzimidazoles were analyzed by LC/MS on XTerra $C_{18}$ column with 0.01% trifluoroacetic acid-acetonitrile (TFA) in a gradient mode as mobile phase, and that were identified by electrospray ionization with selected ion recording mode at 150-350 amu mass range. Residual benzimidazoles were extracted from tissue with ethylacetate, and elute benzimidazoles with $50\%$ acetonitrile. In the LC/MS analysis of benzimidazoles, signal to noise ratio was showed relatively high in the positive mode and special ion in the quality analysis was determined via $[M+H]^+$ and Fragment ions. A spectrum of benzimidazoles was showed from all 6 benzimidazoles

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.709-714
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• 2014

Protein tyrosine nitration is considered as an important indicator of nitrosative stresses and as one of the main factors for pathogenesis of inflammation and neuronal degeneration. In this study, we investigated various nitrosative modifications of bovine carbonic anhydrase II (CAII) through qualitative and semi-quantitative analysis using the combined strategy of Fourier transformation ion cyclotron resonance mass spectrometry (FT-ICR MS) and ion-trap tandem mass spectrometry (IT-MS/MS). FT-ICR MS and its spectra were used for the search of the pattern of nitrosative modifications. Identification of nitrosatively modified tyrosine sites were executed through IT-MS/MS. In addition, we also tried to infer the reason for the site-specific nitrosative modifications in CAII. In view of the above purpose, we have explored- i) the side chain accessibility, ii) the electrostatic environment originated from the acidic/basic amino acid residues neighboring to the nitrosatively modified site and iii) the existence of competing amino acid residues for nitration.

• 한국환경과학회지
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• 제23권6호
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• pp.1037-1047
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• 2014

A highly sensitive analytical method based on stir bar sorptive extraction (SBSE) technique and gas chromatography/tandem mass spectrometry (GC/MS-MS) has been developed, allowing the simultaneous multi-analyte determination of seven UV filters in water samples. The stir bar coated with polydimethylsiloxane (PDMS) was added to 40 mL of water sample at pH 3 and stirred at 1,100 rpm for 120 min. Other SBSE parameters (salt effect and presence of organic solvent) were optimised. The method shows good linearity (coefficients > 0.990) and reproducibility (RSD < 12.9%). The extraction efficiencies were above 84% for all the compounds. The limits of detections (LOD) and limits of quantification (LOQ) were 2.1~8.6 ng/L and 6.8~27.5 ng/L, respectively. The developed method offers the ability to detect 8 UV filters at ultra-low concentration levels with only 40 mL of sample volume. Matrix effects in tap water, river water, wastewater treatment plant (WWTP) final effluent water and seawater were investigated and it was shown that the method is suitable for the analysis of trace level of 7 UV filters except of benzophenone (BP). The method developed in the present study has the advantage of being rapid, simple, high-sensitive and both user and environmentally friendly.

• 대한기계학회논문집 C: 기술과 교육
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• 제2권1호
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• pp.21-28
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• 2014

MS 엑셀 프로그램은 사업 영역의 다양한 분야에서 활용되고 있는 스프레드시트 프로그램이다. MS 엑셀 프로그램은 대부분의 PC 에서 이용 가능하기 때문에 학생들을 위한 교육적인 목적으로 도 널리 이용되는데, 과학과 공학 분야에서는 주로 수치해석과 공식의 응용 등에 주로 사용된다. 본 논문에서는 기계공학의 필수 과목인 정역학을 교육함에 있어 필수 공식을 활용하기 위한 MS 엑셀 프로그램의 교육사례를 소개한다. 또한, 엑셀 응용 프로그램에 대한 깊은 이해를 위하여 매크로와 비주얼 베이직을 이용하여 응용 프로그램을 개발하는 과정에 대해서도 기술한다. 학생들은 MS 엑셀 프로그램의 기본 함수를 이용하여 정역학 문제를 해결할 수 있었을 뿐만 아니라 매크로와 비주얼 베이직을 이용하여 복잡한 문제를 체계적으로 푸는 방법을 습득하고, 응용프로그램을 작성할 수 있었다.

• 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.

• 분석과학
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• 제23권4호
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• pp.405-413
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• 2010

축산물(소의 근육 및 간)중에 잔류하는 합성 글루코코티코이드 6종 (betamethasone, dexamethasone, prednisone, prednisolone, methylprednisolone, flumethasone)에 대한 동시분석방법을 확립하였다. 효과적인 기기분석을 위해서 시료는 C18 고체상 카트리지를 사용하여 에틸아세테이트 용매를 사용하여 추출/정제하였다. C18 컬럼을 사용하여 분리한 후 음이온 전기분무 질량분석법의 multiple reaction monitoring 방법을 사용하여 정량 및 정성 분석을 수행하였다. 효과적이고 감도있는 HPLC-MS/MS 분석을 위해서 0.1% 포름산이 포함된 물과 아세토나이트릴이 이동상 용매로 사용되었다. 메트릭스와 약물의 종류에 따라서 검출한계(LOD)는 $0.2-0.1\;{\mu}g$/kg, 정량한계(LOQ)는 $0.8-3.4{\mu}g$/kg 이었으며, 회수율은 89.5-119.6%이었다. 확립된 기존의 방법들에 비해 6종의 글루코코티코이드의 동시분석 방법이 간소화되었고, 좋은 정확도, 정밀도 및 회수율을 나타내었으며, 축산 육류 중에 잔류하는 글루코코티코이드들 분석하는데 사용될 수 있을 것이다.

• 보존과학회지
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• 제34권5호
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• pp.369-377
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• 2018

경북 경산에 위치한 원삼국시대 고분인 임당1호분에서 출토된 칠초 철제 고리자루칼의 칠편에 대해 칠의 구성성분과 풍화상태를 확인하기 위해 열분해/GC/MS법으로 유기물을 분석하였다. 직접 열분해/GC/MS법에서 칠편과 원주산 건조옻이 대체적으로 유사한 크로마토그램을 보였다. THM(thermally assisted hydrolysis and methylation)-열분해/GC/MS법의 경우 칠편에서 한국에 자생하는 옻나무 종의 특징적인 성분(1,2-dimethoxy-3-pentadecylbenzene 등)이 관찰되었다. 또한, dimethyl nonanedioate 등 건성유에서 비롯되는 것으로 보이는 성분도 검출되었다. 칠편에서 산화된 catechol 성분이 다량 검출되는 것으로 보아 칠의 열화가 우루시올 성분의 산화와 관련 있을 것으로 추정된다. 이로부터 임당1호분 고리자루칼 칠은 옻과 건성유를 사용하였고 오랜 시간의 경과로 산화가 많이 진행된 상태인 것으로 판단된다.

• 한국환경농학회지
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• 제23권4호
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• pp.197-202
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• 2004

토양과 지하수에서 pendimethalin의 지속성은 환경에 해로운 영향을 미친다. 경남 마산에서 분리한 pendimealalin분해 균주는 API CHB50 kit 시험, FAME분석, 그리고 16S rDNA 염기서열분석 결과로 Bacillus sp. MS202로 잠정적으로 동정하였다. TLC, GC, 그리고 GC-MS 분석에 의해 Bacillus sp. MS202가 pendimethalin의 $-NO_2$를 $-NH_2$로 환원시킨다는 것을 알 수 있었다. 이는 일반적으로 알려진 호기성 미생물에 의한 pendimethalin 분해가 탈알킬화가 우선한다는 보고와 상반되는 새로운 결과이다.