• 제목, 요약, 키워드: multiple column curves

검색결과 19건 처리시간 0.028초

중심압축하중을 받는 스테인리스 강관 기둥의 좌굴내력에 관한 연구 (A Study on the Buckling Strength of Centrally Compressed Stainless Steel Tubular Columns)

  • 장호주;양영성
    • 한국강구조학회 논문집
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    • v.17 no.2
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    • pp.207-216
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    • 2005
  • 본 논문은 스테인리스 각형강관 및 원형강관에 대한 좌굴내력에 관한 연구로서 건축구조용 강재로서의 적용성 검토를 위해, 세장비를 주요 변수로 한 소재의 인장강도실험과 stub-column의 압축강도실험, 기둥의 중심압축실험을 실시하여 강재의 기계적 성질과 기둥의 강도 및 거동을 파악한다. 또한 이론해석과 각국 기준식(AIK-LSD, AISC-LRFD, AIJ-LSD, SIJ-ASD) 및 복수강도곡선의 적용을 통한 이론값과 실험값을 비교함으로서 건축구조용 강재로서 적용성 검토와 구조설계기준 확립을 위한 기초 자료를 구하는데 목적이 있다.

Methylisothiocyanate를 이용한 아미노산 배열결정시 N(O)-butyldimethylsilyl 유도체로서의 methylthiohydantoin 아미노산의 기체 크로마토그래피에 의한 분석 (Gas-chromatographic determination of methylthiohydantoin amino acid as N(O)-butyldimethylsilyl derivatives in amino acid sequencing with methylisothiocyanate)

  • 우강융
    • Applied Biological Chemistry
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    • v.35 no.2
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    • pp.132-138
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    • 1992
  • Methylisothiocyanate에 의한 단백질의 아미노산 배열 결정시 순차적으로 분리되어 나오는 methylthiohydantion 아미노산을 기체 크로마토그라피로 효과적으로 정성 및 정량하기위하여 새로운 silylating reagent인 N-methyl-N-(tert.-butyldimethylsily)trifluoroacetamide를 사용하여 N-tert.-butyldimethylsily MTH 유도체로 silylation 한 후 HP-1 capillary column으로 분석하였다. Cystine을 제외한 21개의 단백질 구성 아미노산을 동정할 수 있었고 지금까지 packed column에서 TMS 유도체로 동정할 수 없었던 arginine도 분리 동정되었다. 2개 이상의 peak를 나타낸 것으로는 hydroxyproline, proline, isoleucine, glycine 및 tyrosine이었고 이중 hydroxyproline은 많은 수의 peak들로 분리되었다. Lysine, histidine 및 arginine은 주입량 $5.0\;nmole{\sim}15.0\;nmole$의 범위에서 나머지는 $2.5\;nmole{\sim}7.5\;nmole$의 범위에서 상관관계를 측정한 결과 고도의 직선 상관관계를 나타내었다(p<0.001). TMS 유도체에 의한 분석은 많은 불순 peak들 때문에 정량분석에 이용할 수 없었다.

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Rapid Determination of Ginkgolic Acids in Ginkgo biloba Leaf Using Online Column Switching High-Performance Liquid Chromatography-Diode Array Detection and Confirmation by Liquid Chromatography-tandem Mass Spectrometry

  • Lee, Hyounyoung;Lim, Heungyoul;Yang, Juhong;Hong, Jongki
    • Bulletin of the Korean Chemical Society
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    • v.34 no.12
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    • pp.3629-3634
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    • 2013
  • In this study, an improved method for the quantitative analysis of ginkgolic acids (GAs) in Ginkgo biloba leaf extract was developed. The samples were extracted with a mixture of chloroform and 50 % ethanol, after which the chloroform extract was dried and reconstituted in methanol. GAs with 13:0, 15:1, and 17:1 in the extract were successfully separated within 40 min and determined with high throughput performance using an online column-switching HPLC method using an SP column C8 SG80 ($4.6{\times}150mm$, $5{\mu}m$) and a Cadenza 5CD C18 column ($4.6{\times}150mm$, $3{\mu}m$). The developed HPLC method was validated for Ginkgo biloba leaf extract. The validation parameters were specificity, linearity, precision, accuracy, and limits of detection and quantitation (LODs and LOQs, respectively). It was found that all of the calibration curves showed good linearity ($r^2$ > 0.9993) within the tested ranges. The LODs and LOQs were all lower than $0.04{\mu}g/mL$. The established method was found to be simple, rapid, and high throughput for the quantitative analysis of GAs in ten commercial Ginkgo biloba leaf extract and dietary supplements. The samples were also analyzed in LC-electrospray ionization (ESI) tandem mass spectrometry (MS/MS) - multiple-ion reaction monitoring (MRM) mode to confirm the identification results that were obtained by the column switching HPLC-DAD method. The developed method is considered to be suitable for the routine quality control and safety assurance of Ginkgo biloba leaf extract.

Data Base에 의한 CFT 기둥의 내력에 관한 연구 (A Study on the Strength of Concrete Filled Tubular Columns according to Data-Base)

  • 서정환;양영성
    • 한국강구조학회 논문집
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    • v.13 no.1
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    • pp.71-79
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    • 2001
  • 본 연구는 콘크리트 충전강관을 고층 건축구조물의 기둥부재로의 이용을 위한 연구의 일환으로 필자의 실험결과와 그동안 국내에서 발표된 콘크리트충전 강관 기둥에 관한 연구논문(1991.1~2000.6)의 실험결과 값을 데이터 베이스를 통해 콘크리트 충전으로 인한 내력 상승효과와 세장비에 따른 내력 등을 파악하여 다음과 같은 결론을 얻었다. 콘크리트 충전 강관 단주의 콘크리트 충전으로 인한 내력 상승효과는 단면형태에 따라 달리 나타나며, 누가강도에 비해 충전각형 강관은 1.102배 충전원형강관은 1.279배의 내력상승효과를 나타냈다. 압축력과 휨을 받는 콘크리트 충전강관의 폭-두께비는 국내의 비충전 강관의 폭-두께비에 비해 충전각형관은 1.3배 충전원형강관은 1.6배 이상 완화할 수 있음을 알 수있었다. 충전 효과를 고려한 중심축 하중을 받는 콘크리트 충전 강관 기둥의 내력식을 제안하였다. 실험데이트를 대표적인 복수강도 곡선인 SSRC 곡선 및 ECCS 곡선과 비교하였다.

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LC-ESI-MS에 의한 사군자탕의 지표성분 분석 (Analysis of the Marker Compounds in Sagunja-tang by LC-ESI-MS)

  • 서창섭;신현규
    • 생약학회지
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    • v.50 no.1
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    • pp.65-71
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    • 2019
  • One of the oriental medicine prescriptions, Sagunja-tang consists of four herbal medicines (Ginseng Radix, Poria Sclerotium, Atractylodis Rhizoma Alba, and Glycyrrhiziae Radix et Rhizoma) and has been used as a medicine to enhance tonify the function of spleen and stomach in Korea. In this study, we conducted simultaneous analysis of the 9 marker components, liquiritin apioside, liquiritin, ginsenoside Rg1, liquiritigenin, ginsenoside Rb1, glycyrrhizin, atractylenolide III, atractylenolide II, and atractylenolide I in Sagunja-tang using a liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS). Marker compounds were separated on a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, 1.7 mm) and the column was maintained at $45^{\circ}C$. The mobile phase consists of 0.1% (v/v) aqueous formic acid and acetonitrile with gradient condition. The LC-MS analysis was performed using a Waters ACQUITY TQD LC-MS/MS system with multiple reaction monitoring (MRM) method in the positive and negative modes. The calibration curves of the nine marker components showed good linearity with coefficient of determination ${\geq}0.9984$ within tested range. The limits of detection and limits of quantification values were 0.27-2.42 ng/mL and 0.81-7.27 ng/mL, respectively. The concentrations of tested 9 analytes in the lyophilized Sagunja-tang sample using the established LC-ESI-MS/MS MRM method were detected up to 16.593 mg/g. These results can be useful as a basic data for the quality control of an oriental medicine prescriptions.

LC-ESI-MS/MS를 이용한 계지탕 중 주요 성분 분석 (Quantitative Determination of the Bioactive Marker Components in Gyeji-tang Using LC-ESI-MS/MS)

  • 서창섭;하혜경
    • 생약학회지
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    • v.49 no.1
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    • pp.76-83
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    • 2018
  • A traditional herbal formula, Gyeji-tang has been used to treat the early colds, headache, chills, and fever in Asian countries. In this study, we were performed simultaneous determination of the 14 bioactive marker compounds, gallic acid, spinosin, paeoniflorin, albiflorin, liquiritin apioside, liquiritin, 6'''-feruloylspinosin, liquilitigenin, coumarin, cinnmamic acid, benzoylpaeoniflorin, cinnamaldehyde, glycyrrhizin, and 6-gingerol in Gyeji-tang using an ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS/MS). Analytical column was used a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$) and maintained at $45^{\circ}C$ with a flow rate of 0.3 mL/min. The mobile phase consists of 0.1% (v/v) formic acid in water and acetonitrile with gradient elution. The MS analysis was conducted using multiple reaction monitoring in the positive and negative modes by a Waters ACQUITY TQD LC-MS/MS system. The calibration curves of 14 bioactive marker compounds showed linearity with correlation coefficients ${\geq}0.9798$. The limits of detection and quantification values were in the range of 0.11-6.66 ng/mL and 0.34-19.99 ng/mL, respectively. As a result of the analysis using the established LC-MS/MS method, the amounts of tested 14 compounds in the lyophilized Gyeji-tang sample were detected up to $85.7{\mu}g/g$. These results may be useful for quality assessment of a traditional herbal formulas.

Development and validation of LC-MS/MS for bioanalysis of hydroxychloroquine in human whole blood

  • Park, Jung Youl;Song, Hyun Ho;Kwon, Young Ee;Kim, Seo Jin;Jang, Sukil;Joo, Seong Soo
    • Journal of Biomedical and Translational Research
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    • v.19 no.4
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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.

Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Determination of ε-Acetamidocaproic Acid in Rat Plasma

  • Kim, Tae Hyun;Choi, Yong Seok;Choi, Young Hee;Kim, Yoon Gyoon
    • Toxicological Research
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    • v.29 no.3
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    • pp.203-209
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    • 2013
  • A simple and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of ${\varepsilon}$-acetamidocaproic acid (AACA), the primary metabolite of zinc acexamate (ZAC), in rat plasma by using normetanephrine as an internal standard. Sample preparation involved protein precipitation using methanol. Separation was achieved on a Gemini-NX $C_{18}$ column ($150mm{\times}2.0mm$, i.d., 3 ${\mu}m$ particle size) using a mixture of 0.1% formic acid-water : acetonitrile (80 : 20, v/v) as the mobile phase at a flow rate of 200 ${\mu}l/min$. Quantification was performed on a triple quadrupole mass spectrometer employing electrospray ionization and operating in multiple reaction monitoring (MRM) and positive ion mode. The total chromatographic run time was 4.0 min, and the calibration curves of AACA were linear over the concentration range of 20~5000 ng/ml in rat plasma. The coefficient of variation and relative error at four QC levels were ranged from 1.0% to 5.8% and from -8.4% to 6.6%, respectively. The present method was successfully applied for estimating the pharmacokinetic parameters of AACA following intravenous or oral administration of ZAC to rats.

Simultaneous HPLC determination of multiple compounds in a cosmetic lotion

  • Baeksun Ahn;Jung, Chul-Hee;Lim, Ho-Soon;Lee, Hoosub;Lee, Sang-Hoon
    • 대한화장품학회지
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    • v.29 no.1
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    • pp.123-134
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    • 2003
  • 고속액체크로마토그래피 방법을 사용하여 동시에 arbutin, 메탄올에 녹인 methyl, ethyl, prpyl, butyl parben과 glablidien(유용성감초추출물)을 파장 254와 276 nm에서 Gradient methanol로 octdecyl culumn을 사용하여측정하였다. arbutin와 glablidien 농도 0.5-1.0 ug/ml 파라벤류는 0.1-2.0 ug/ml에서 검량선이 직선으로 작성되었다. 검량이 직선으로 나타나 정량분석을 할 수 있다는 것을 알 수 있었다. 샘플 전처리가 크로마토그래피로 측정하기에 좋은 방법이란 것을 판정하기 위하여 일반로션을 사용하여 판정하였다. 이 방법의 정확도는 모든 측정물질(arbutin, methylparaben, ethylparaben, propylparaben, butylparaben, glablidine)의 회수율 상대표준편차(RSD)가 (0.28-2.55%) 나타나 신뢰성 있는 결과를 보였다.A high-performance liquid chromatographic method for the simultaneous determination of arbutine, a mixture of methyl, ethyl, propyl, butyl parabens dissolved in methoanol and Glrablidine(Oil Soluble Licorice), was studied by using a ODS C18 column and a methanol gradient at 254 and 276 nm. Calibration curves were found to be linear in the 0.5-1.0 ug/ml range(compounds arbutine, glrablidin) and 0.1-20 ug/ml (compounds methylpaaben, ethylparaben, propylparaben, butylparaben). Linear regression analysis of the data demonstrates the efficacy of the method in terms of precision and accuracy. An extraction method is developed and validated in order to apply this chromatographic method to a cosmetic lotion. The presision of this method, calculated as the relativ standard deviation(RSD) of the recoveries(0.28-2.55%) was excellent for all compounds.

Hydrophillic Interaction Chromatography-tandem Mass Spectrometry Method for Identification and Quantitation of 5-MeO-DIPT and its Metabolites in Rat Urine

  • Kim, Yoon;Kim, Un-Yong;In, Moon-Kyo;Lee, Jae-Ick;Kwon, Oh-Seung;Yoo, Hye-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.32 no.4
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    • pp.1158-1164
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    • 2011
  • 5-Methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT), a psychoactive tryptamine derivative, is a hallucinogenic drug of abuse. In this study, 5-OH-DIPT and its metabolites were identified and the quantitative method was developed and validated by using hydrophilic interaction chromatography-tandem mass spectrometry (HILICMS/MS). Chromatographic separation was achieved on an Atlantis HILIC silica column ($5{\mu}m$, $100{\times}2.1\;mm$). The metabolites of 5-MeO-DIPT in rat urine were characterized via Q1 scanning and product ion scanning. As a consequence, 5-MeO-IPT, 5-OH-DIPT, 6-OH-5-MeO-DIPT and their glucuronide conjugates were detected and identified as the metabolites of 5-MeO-DIPT. Subsequently, a quantitative method for 5-MeO-DIPT and its major metabolites, 5-MeO-IPT and 5-OH-DIPT, was developed in multiple reactions monitoring (MRM) mode. The calibration curves for all analytes evidenced good linearity over the concentration range of 1-1000 ng/mL with linear correlation co-efficients ($r^2$) in excess of 0.99. The intra- and inter-day accuracy and precision were 92.2-110.2% and 1.5-9.9%, respectively.