• Title/Summary/Keyword: coupled column chromatography

Search Result 98, Processing Time 0.03 seconds

Determination of S- and R-Amlodipine in Rat Plasma using LC-MS/MS After Oral Administration of S-Amlodipine and Racemic Amlodipine

  • Yoo, Hye-Hyun;Kim, Tae-Kon;Lee, Bong-Yong;Kim, Dong-Hyun
    • Mass Spectrometry Letters
    • /
    • v.2 no.4
    • /
    • pp.88-91
    • /
    • 2011
  • The pharmacokinetic properties of S-amlodipine were studied using racemic amlodipine and single S-enantiomer (SK310) administration to rats. Plasma levels of the drug were determined using chiral liquid chromatography coupled with tandem mass spectrometry following solid phase extraction. The stereospecific analysis of amlodipine was performed on an ${\alpha}$-acid glycoprotein (AGP) column using a mobile phase comprising 10 mM ammonium acetate (pH 4.0) and propanol at a flow rate of 0.2 mL/min. This method was used to perform a comparative study of the pharmacokinetics of amlodipine and SK310. The results revealed that the pharmacokinetic profile of S-amlodipine after the administration of SK310 was comparable to that following the administration of the racemic mixture.

Determination of Iron, Copper, and Zinc in Rainwater by Ion Chromatography (이온 크로마토그래피법에 의한 강수 중 철, 구리, 아연의 정량)

  • 이용근;이계형;이동수
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.7 no.2
    • /
    • pp.137-142
    • /
    • 1991
  • A method is developed for the simultaneous determination of dissolved iron, copper, and zinc in rainwater. The method involves 25-fold evaporative concentration, ion chromatographic separation and subsequent spectrophotometric detection after post-column reaction with 4-(2-pyridylazo) resorcinol. Analytical sensitivities, being defined by the slopes of calibration curves, are 0.93, 0.54, and 0.11 Abs/ $\mu$g/ml for iron, copper, zinc, respectively. Detection limits render around a few tenth of one ng/ml. Precisions evaluated by replicate analysis of real sample are better than 10% RSD. Due to the lack of certified standards for rainwater, the accuracy of the method could not be assessed directly. However, the results of this method agree well with those by inductively coupled plasma mass spectrometry. Analytical results for a suite of Seoul rainwaters are presented herein.

  • PDF

Studies on the Antioxidative Substances in the Seeds of Some Theaceae Family (동백(冬柏)을 위시한 차나무과(科) 식물(植物) 종실(種實)에 함유(含有)된 항산화제(抗酸化劑)에 관한 연구(硏究))

  • Kim, Seong-Jin;Choi, Eun-Jin;Lim, Hee-Ryeong;Kim, Tae-Sook;Joh, Yong-Goe
    • Journal of the Korean Applied Science and Technology
    • /
    • v.8 no.1
    • /
    • pp.35-43
    • /
    • 1991
  • Dried seeds of Camellia japonica and Thea sinensis were investigated to determine the nature of their antioxidative activity. Activity was measured by the induction period in the coupled oxidation of a substrate lard and extracts or isolates to be tested. 70% methanol and dichloromethane extracts were found to be antioxidative abilities. Their unsaponifiables revealed weak antioxidative activity, although hexane extracts did not show antioxidative effect on lard. Column chromatography for dlchloromethane extracts gave 4 fractions(only 2 fractions were potent). HPLC was used in isolating potent antioxidative components from the column fractions and the precolumn-passed methanol extracts. They were separated into 7 and 8 components, respectively. The column fractions obtained from both seeds comprised trans-p-coumaric acid. trans-p-ferulic acid and an unknown component with minor components such as chlorogenic acid and catechin. On the other hand, the most prominent components in the methanol extracts were an unidentified component. trans-pcoumaric acid, trans-p-ferulic acid, catechin and chlorogenic acid. The unknown compound isolated from the column fractions and methanol extracts was identified as epicatechin by $^1H-and\;^{13}C-NMR$. The antioxidative activities of these components were epicatechin > catechin > chlorogenic acid > trans-p-ferulic acid > trans-p-coumaric acid.

Qualitative and quantitative analysis of the saponins in Panax notoginseng leaves using ultra-performance liquid chromatography coupled with time-of-flight tandem mass spectrometry and high performance liquid chromatography coupled with UV detector

  • Liu, Fang;Ma, Ni;He, Chengwei;Hu, Yuanjia;Li, Peng;Chen, Meiwan;Su, Huanxing;Wan, Jian-Bo
    • Journal of Ginseng Research
    • /
    • v.42 no.2
    • /
    • pp.149-157
    • /
    • 2018
  • Background: Panax notoginseng leaves (PNL) exhibit extensive activities, but few analytical methods have been established to exclusively determine the dammarane triterpene saponins in PNL. Methods: Ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC/Q-TOF MS) and HPLC-UV methods were developed for the qualitative and quantitative analysis of ginsenosides in PNL, respectively. Results: Extraction conditions, including solvents and extraction methods, were optimized, which showed that ginsenosides Rc and Rb3, the main components of PNL, are transformed to notoginsenosides Fe and Fd, respectively, in the presence of water, by removing a glucose residue from position C-3 via possible enzymatic hydrolysis. A total of 57 saponins were identified in the methanolic extract of PNL by UPLC/Q-TOF MS. Among them, 19 components were unambiguously characterized by their reference substances. Additionally, seven saponins of PNL-ginsenosides Rb1, Rc, Rb2, and Rb3, and notoginsenosides Fc, Fe, and Fd-were quantified using the HPLC-UV method after extraction with methanol. The separation of analytes, particularly the separation of notoginsenoside Fc and ginsenoside Rc, was achieved on a Zorbax ODS C8 column at a temperature of $35^{\circ}C$. This developed HPLC-UV method provides an adequate linearity ($r^2$ > 0.999), repeatability (relative standard deviation, RSD < 2.98%), and inter- and intraday variations (RSD < 4.40%) with recovery (98.7-106.1%) of seven saponins concerned. This validated method was also conducted to determine seven components in 10 batches of PNL. Conclusion: These findings are beneficial to the quality control of PNL and its relevant products.

Ion Exchange of Glutamic Acid Coupled with Crystallization (결정화 반응이 결합된 글루탐산의 이온교환)

  • 이기세
    • KSBB Journal
    • /
    • v.11 no.5
    • /
    • pp.606-612
    • /
    • 1996
  • A specific ammino auid in a mixture can be crystallized inside an ion exchange column when displacer concentration is high enough to concentrate the amino acid in a pure band beyond its solubility limit. Glutamic acid formpd a discrete crystal layer in a cation exchanger column by operating displacement development mode and using a high concentration of displacer NaOH. The glutamic acid crystal formed was eluded from the column with the effluent stream and collected in a fraction collector. When 1.0 M of NaOH was used as a displacer, more than 60% of the loaded glutamic acid was recovered as crystal. The continuous crystallization and dissolution of crystal occurred, resulting in apparent movement of the crystal along the column without clogging or pressure increase. NaOH was proved a better displacer than NaCl because hydroxide ions neutralized hydrogen ions released from the resin and thus reduced the number of hydrogen ion competing with sodium ion for re-adsorption. The displacement development process coupled with crystallization provided higher concentration and recovery of glutamic acrid than conventional chromatography.

  • PDF

Pentafluorophenylprophyl Ligand-based Liquid Chromatography-Tandem Mass Spectrometric Method for Rapid and Reproducible Determination of Metformin in Human Plasma

  • Yang, Jeong Soo;Oh, Hyeon Ju;Jung, Jin Ah;Kim, Jung-Ryul;Kim, Tae-Eun;Ko, Jae-Wook;Lee, Soo-Youn;Huh, Wooseong
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.11
    • /
    • pp.3284-3288
    • /
    • 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.

Development of an analytical method for the determination of dl-methylephedrine hydrochloride in porcine muscle using liquid chromatography-tandem mass spectrometry (LC-MS/MS를 이용한 돼지 근육조직 중 dl-methylephedrine hydrochloride의 잔류 분석법 개발)

  • Chae, Won-Seok;Kim, Suk;Lee, Hu-Jang
    • Korean Journal of Veterinary Research
    • /
    • v.60 no.4
    • /
    • pp.209-213
    • /
    • 2020
  • This study examined the residue of dl-methylephedrine hydrochloride (MEP) on the muscle of pigs administered orally with MEP 12 g/ton feed for seven consecutive days. Twenty healthy cross swine were administered MEP. Four treated animals were selected arbitrarily to be sacrificed at 1, 2, 3, 4, and 5 days after treatment. MEP residue concentrations in the muscle were determined by liquid chromatography coupled with tandem mass spectrometry. The drug was extracted from muscle samples using 10 mM ammonium formate in acetonitrile followed by clean-up with n-hexane. The analyte was separated on an XBridgeTM hydrophilic interaction liquid chromatography column using 10 mM ammonium formate in deionized distilled water and acetonitrile. The correlation coefficient (R2) of the calibration curve was 0.9974, and the limits of detection and quantification were 0.05 and 0.15 ㎍/kg, respectively. The recoveries at three spiking levels were 94.5-101.2%, and the relative Standard Deviations was less than 4.06%. In the MEP-treated group, MEP residues on one day post-treatment were below the maximum residue limit in the muscle. The developed method is sensitive and reliable for the detection of MEP in porcine muscle tissues. Furthermore, it exhibits low quantification limits for animal-derived food products destined for human consumption.

Quantitative Speciation of Selenium in Human Blood Serum and Urine with AE- RP- and AF-HPLC-ICP/MS

  • Jeong, Ji-Sun;Lee, Jonghae;Pak, Yong-Nam
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.12
    • /
    • pp.3817-3824
    • /
    • 2013
  • Various separation modes in HPLC, such as anion exchange (AE), reversed-phase (RP), and affinity (AF) chromatography were examined for the separation of selenium species in human blood serum and urine. While RP- and AE-HPLC were mainly used for the separation of small molecular selenium species, double column AF-HPLC achieved the separation of selenoproteins in blood serum efficiently. Further, the effluent of AF-HPLC was enzymatically hydrolyzed and then analyzed with RP HPLC for selenoamino acid study. The versatility of the hybrid technique makes the in-depth study of selenium species possible. For quantification, post column isotope dilution (ID) with $^{78}Se$ spike was performed. ORC ICP/MS (octapole reaction cell inductively coupled plasma/mass spectrometry) was used with 4 mL $min^{-1}$ Hydrogen as reaction gas. In urine sample, inorganic selenium and SeCys were identified. In blood serum, selenoproteins GPx, SelP and SeAlb were detected and quantified. The concentration for GPx, SelP and SeAlb was $22.8{\pm}3.4\;ng\;g^{-1}$, $45.2{\pm}1.7\;ng\;g^{-1}$, and $16.1{\pm}2.2\;ng\;g^{-1}$, respectively when $^{80}Se/^{78}Se$ was used. The sum of these selenoproteins ($84.1{\pm}4.4\;ng\;g^{-1}$) agrees well with the total selenium concentration measured with the ID method of $87.0{\pm}3.0\;ng\;g^{-1}$. Enzymatic hydrolysis of each selenium proteins revealed that SeCys is the major amino acid for all three proteins and SeMet is contained in SeAlb only.

Chiral Separation of the Enantiomers of Metoprolol and Its Metabolites by High Performance Liquid Chromatography

  • Kim, Kyeong-Ho;Shin, Sang-Duk;Lee, Joo-Hyun;Lee, Sang-Cheal;Kang, Jong-Seong;Mar, Woong-chon;Hong, Seon-Pyo;Kim, Hyun-Ju
    • Archives of Pharmacal Research
    • /
    • v.23 no.3
    • /
    • pp.230-236
    • /
    • 2000
  • (1'R, 2R)-, (1'R, 2S)-, (1'S, 2R)- and (1'S, 2S)-$\alpha$-hydroxymetoprolol; (2R)- and (2S)-O-des-methylmetoprolol; and (2R)- and (2S)-metoprolol acid are major metabolites of (2R)-and (2S)-metoprolol, $\beta$-adrenergic antagonist. The focus of most chiral separation methods until now has been on determination of the enantiomeric parent drug. However, it is just as important to be able to follow the metabolism of the enantiomers and their possible chiral metabolites. Therefore, for the study of stereoselective metabolism and pharmacokinetics of metoprolol, the chiral separation of the enantiomers of metoprolol and its metabolites has been investigated using four chiral stationary phases, i.e., Chiralcel OD, Chiral-AGP, Cyclobond I and Sumichiral OA-4900 columns. Metoprolol acid was resolved only by Sumichiral OA-4900. Chiralcel OD provided the highest separation factor and resolution value for metoprolol and O-desmethylmetoprolol and partially resolved the four stereoisomers of $\alpha$-hydroxymetoprolol. Diastereomeric $\alpha$-hydroxymetoprolols were resolved using the coupled column chromatographic system of two chiral stationary phases, Sumichiral OA-4900 column and Chiralcel OD column.

  • PDF

Development of Immuno-Analytical System for Microbial Cells by using Dot-Blotter (Dot-Blotter 진공 포획방식에 의한 미생물세포 면역분석시스템의 개발)

  • 목락선;하연철;윤희주;백세환
    • KSBB Journal
    • /
    • v.14 no.1
    • /
    • pp.82-90
    • /
    • 1999
  • In order to eventually fabricate an analytical system for infectious microorganisms, we synthesized major immunochemical components, utilized them for the construction of model system, and investigated an assay concept for bacterial whole cells. For the preparation of system components, a polyclonal antibody, against Salmonella thompson as model analyte, purified by immuno-affinity chromatography was used to chemically link to streptavidin or an enzyme, horseradish peroxidase(HRP). The antibody and streptavidin was modified with sulfosuccinimidyl 4-[N-maleimidomethyl]cyclohexane-1-carboxylate and N-succinimidyl-3-[2-pyridyldithio]propionate(subsequently activated by dithiotheritol), respectively. The modified components were reacted to synthesize antibody-streptavidin conjugates which were then purified on a two-layer chromatography column of diaminobiotin gel and Sephadex G-100. For antibody-HRP conjugates, HRP molecules were activated by $NalO_4$ oxidation and then coupled to immunoglobulin. After stabilizing with ($NaCNBH_3$, the conjugates were purified by size exclusion chromatography on Biogel A5M column. To devise a model system, such produced components were combined with a dot-blotter in which a nitrocellulose membrane($12{\mu}m$ pre size) with immobilized biotin was already located. The analyte (S. thompson cells) was reacted with the both antibody conjugates in a liquid phase, and the complexes formed were captured on the membrane surfaces by applying vacuum in the bottom compartment of the blotter to invoke biotin-streptavidin reaction. Under optimal conditions, the system enabled to identify the analytical concept for bacterial whole cells, and the lower limit of detection was approximately $1{\mu}g/m{\ell}$($10^5-10^6$ cells/m$m{\ell}$). The controlling factors were the concentrations of each antibody conjugate that caused agglutination in the presence of analyte as they increased.

  • PDF