• Title, Summary, Keyword: RPLC

Search Result 25, Processing Time 0.039 seconds

Retention of Benzoic Acids in RPLC (역상액체크로마토그래피에서 벤조산류의 머무름)

  • Lee, Jae-Seok;Choi, Beom-Suk
    • Analytical Science and Technology
    • /
    • v.13 no.3
    • /
    • pp.269-276
    • /
    • 2000
  • Chromatographic retention mechanism of seven benzoic acids in RPLC were investigated. Inorganic salt is pertinent for the measurement of dead time in benzoic acid. Logarthims of capacity factor (log k') and Hildebrand solubility parameter (${\delta}$) showed proportional relationship which imply the hydrophobic effect of the retention mechanism in RPLC. Enthalpies of solute transfer showed inverse proportion to temperature and organic modifier ratio of the mobile phase. It was found that the S value showed positive slope in plot of log k' vs. volume fraction of water in mobile phase. Free energy change increases with increasing organic volume fraction. The hydrophobicity index, ${\varphi}_0$(organic volume fraction) is inversely proportional to column temperature.

  • PDF

Fluorimetric Determination of Dichloroacetamide by RPLC with Postcolumn Detection

  • Choi, Yong-Wook;Reckhow, David A.
    • Bulletin of the Korean Chemical Society
    • /
    • v.25 no.6
    • /
    • pp.900-906
    • /
    • 2004
  • An RPLC-postcolumn detection method has been developed for the fluorimetric determination of dichloroacetamide (DCAD) in water. After ammonia and DCAD were separated on a $C_{18}$ nonpolar stationary phase with 2.5% methanol-0.02 M phosphate buffer at pH 3, the column eluant was reacted with post column reagents, o-phthaldialdehyde (OPA) and sulfite ion at pH 11.5, to produce a highly fluorescent isoindole fluorophore, which was measured with a fluorescence detector ( ${\lambda}_{ex}$ = 363 nm, ${\lambda}_{em}$ = 425 nm). With the optimized conditions for RPLC and the postcolumn derivatization, the calibration curve was found to be linear in the concentration ranges of 0.5 and 20 ${\mu}$M for DCAD, and the detection limit for DCAD was 0.18 ${\mu}$M (23${\mu}$g/L). This corresponded to 18 pmol per 100 ${\mu}$L injection volume for a signal-to-noise ratio of 3, and the repeatability and reproducibility of this method were 1.0% and 2.5% for five replicate analyzes of 2 ${\mu}$M DCAD, respectively. The degradation yields DCAD to ammonia were 94 and 99%, and the percent recoveries of DCAD from 4 and 6 ${\mu}$M DCAD-spiked tap water were shown mean more than 97%.

Development of Ultra-High Pressure Capillary Reverse-Phase Liquid Chromatography/Tandem Mass Spectrometry for High-Sensitive and High-Throughput Proteomics

  • Kim, Min-Sik;Choie, Woo-Suk;Shin, Yong-Seung;Yu, Myeong-Hee;Lee, Sang-Won
    • Bulletin of the Korean Chemical Society
    • /
    • v.25 no.12
    • /
    • pp.1833-1839
    • /
    • 2004
  • Recently mass spectrometry and separation methods such as liquid chromatography have become major tools in the field of proteomics. In this report, we describe in detail our efforts to develop ultra-high pressure capillary reverse-phase liquid chromatography (cRPLC) and its online coupling to a mass spectrometer by a nanoelectrospray (nanoESI) interface. The RPLC system is constructed in house to deliver LC solvents at the pressure up to 20,000 psig, which is four times higher than conventional RPLC systems. The high operation pressure allows the efficient use of packed micro-capillary columns (50, 75 and 150 ${\mu}$m i.d., up to 1.5 m long). We will discuss the effect of column diameter on the sensitivity of cRPLC/MS/MS experiments and the utility of the developed technique for proteome analysis by its application in the analysis of proteome samples having different levels of complexity.

Effect of Concentration of Ionic Liquids on Resolution of Nucleotides in Reversed-phase Liquid Chromatography

  • Hua, Jin Chun;Polyakova, Yulia;Row, Kyung-Ho
    • Bulletin of the Korean Chemical Society
    • /
    • v.28 no.4
    • /
    • pp.601-606
    • /
    • 2007
  • The chromatographic behaviors of nucleotides (inosine 5'-monophosphate, uridine 5'-monophosphate, guanosine 5'-monophosphate, and thymine monophosphate disodium salts) on a C18 column were studied with different types of ionic liquids (ILs) as additives for the mobile phase in reversed-phase liquid chromatography (RPLC). Three ILs, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIm][BF4]), and 1-ethyl-3-methylimidazolium methylsulfate ([EMIm][MS]), were used. Eluents were composed of water and methanol (90/10%, vol) with the addition of 0.5-13.0 mM of ILs. The effects of the concentration of ILs on retention and separation were investigated and discussed. The results showed that the addition of ILs affects the retention and resolution of the tested compounds. Use of 13.0 mM of [BMIm][BF4] as the eluent modifier resulted in a baseline separation of nucleotides without requiring gradient elution. This study demonstrates that ILs can be potentially applied as a mobile phase modifier in RPLC.

A Study on the Analysis of Polycyclic Aromatic Hydrocarbons by RPLC/DAD (I) (RPLC/DAD를 이용한 Polycyclic Aromatic Hydrocarbon류의 분석에 관한 연구(I))

  • Lee, Won;Hong, Jee-Eun;Park, Song-Ja;Pyo, Hee Soo
    • Analytical Science and Technology
    • /
    • v.10 no.5
    • /
    • pp.315-324
    • /
    • 1997
  • The retention behaviors of 16 PAHs and 4 nitro-PAHs were studied with several parameters involved numbers of carbon atoms, F factor, aqueous solubility, L/B ratio, and numbers of interfering hydrogen atom pairs on the chemical structures of PAHs by using reversed-phase liquid chromatography/diode array detection method (RPLC/DAD) and gradient elution method. It was obtain that the log k' for most of PAHs with increasing the number of carbon and the F factor in their molecules. Chromatographic retention of PAH isomers and nitro-PAHs were examined with aqueous solubility, L/B ratio and number of interfering hydrogen atom pairs. As a result of comparison with these factors and retention times, it was found that those solutes having larger aqueous solubilities and greater L/B ratios were retained longer on stationary phase. This tendency was also occured in the molecules having the more number of interfering hydrogen atom pairs. Detection limits of PAHs which were obtained with three times measurements by RPLC/DAD were in the range of 100~500ng/mL and method detection limit(MDL) for water sample were in the range of 0.1~0.5ng/mL.

  • PDF

Simultaneous Fluorimetric Determination of On-line Preconcentrated HANs, DCAD and TCAD by Using RPLC with a Postcolumn Derivatization System

  • Jung, Sung-Woon;Choi, Yong-Wook
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.6
    • /
    • pp.1783-1790
    • /
    • 2013
  • A simultaneous analytical method has been developed for the fluorimetric determination of haloacetonitriles (HANs) [dichloroacetonitrile (DCAN), trichloroacetonitrile (TCAN), dibromoacetonitrile (DBAN), haloacetamides [dichloroacetamide (DCAD), and trichloroacetamde (TCAD)] in drinking water by using the combined on-line perconcentration/reversed phase liquid chromatography (RPLC)-postcolumn detection system. This on-line perconcentration system was achieved by employing a precolumn packed with a commercial solid phase extraction (SPE) sorbent for the enrichment and purification of the target analytes. The haloacetonitriles and haloacetamides were separated on CN analytical column in a 7.5% methanol-0.02 M phosphate buffered mobile phase at pH 3. The column effluents were reacted with postcolumn reagents of ophthaldialdehyde (OPA) and sulfite ion at pH 11.5, to produce a highly fluorescent isoindole fluorophore, which were measured with a fluorescence detector. Under the optimized conditions for RPLC and the postcolumn derivatization system all of the coefficient of determination of the standard calibration curves for the target analytes were over 0.99 and had a linear range from 5 to 100 ${\mu}g/L$. The detection limits showed 1.6 ${\mu}g/L$ for DCAD, 0.1 ${\mu}g/L$ for TCAD, 0.6 ${\mu}g/L$ for DCAN, 1.6 ${\mu}g/L$ for TCAN and 1 ${\mu}g/L$ for DBAN, and the recoveries were ranged from 64 to 99% except for DCAD with precisions less than 4.9% in distilled water, and from 72(${\pm}4%$) to 116%(${\pm}2%$) in tap water.

Chromatographic Selectivity of Cyano-Bonded Silica Columns in RPLC Based on the Linear Solvation Energy Relationships

  • Park, Jung-Hag;Jang, Myung-Duk;Kwon, Se-Mok
    • Bulletin of the Korean Chemical Society
    • /
    • v.13 no.1
    • /
    • pp.75-79
    • /
    • 1992
  • Differences in chromatographic properties in RPLC of four brands of cyano bonded silica stationary phases are rationalized in terms of the type and relative strength of the solute-stationary phase interactions, which can be readily inferred from multiple linear regression analyses of retention data for a set of standard compounds on the stationary phases under study based on the linear solvation energy relationships (LSERs). Although four brands of cyano bonded columns studied (CPS-Hypersil, Ultrasphere cyano, Spherisorb-CN and ${\mu}$-Bondapak-CN) have similar bonding density and have been prepared from monofunctional cyanopropylsilane reagents, they possess quite different, relative hydrogen bonding (HB) donor and acceptor strengths. Comparison of the retention behavior on a cyano-bonded silica column with that on an ODS column shows that there are significant differences in the strength of HB interactions between the solute and the stationary phase on the two columns with different functionalities. Information on the differences in the interaction characteristics among brands of the cyano-bonded silica columns and between the ODS and cyano-bonded columns can be utilized to optimize the selectivity for a given separation on these columns.

  • PDF

A Comprehensive Identification of Synaptic Vesicle Proteins in Rat Brains by cRPLC/MS-MS and 2DE/MALDI-TOF-MS

  • Lee, Won-Kyu;Kim, Hye-Jung;Min, Hye-Ki;Kang, Un-Beom;Lee, Cheol-Ju;Lee, Sang-Won;Kim, Ick-Young;Lee, Seung-Taek;Kwon, Oh-Seung;Yu, Yeon-Gyu
    • Bulletin of the Korean Chemical Society
    • /
    • v.28 no.9
    • /
    • pp.1499-1509
    • /
    • 2007
  • Proteomic analyses of synaptic vesicle fraction from rat brain have been performed for the better understanding of vesicle regulation and signal transmission. Two different approaches were applied to identify proteins in synaptic vesicle fraction. First, the isolated synaptic vesicle proteins were treated with trypsin, and the resulting peptides were analyzed using a high-pressure capillary reversed phase liquid chromatography/tandem mass spectrometry (cRPLC/MS/MS). Alternatively, proteins were separated by two-dimensional gel electrophoresis (2DE) and identified by matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF/MS). Total 18 and 52 proteins were identified from cRPLC/MS-MS and 2DE-MALDI-TOF-MS analysis, respectively. Among them only 2 proteins were identified by both methods. Of the proteins identified, 70% were soluble proteins and 30% were membrane proteins. They were categorized by their functions in vesicle trafficking and biogenesis, energy metabolism, signal transduction, transport and unknown functions. Among them, 27 proteins were not previously reported as synaptic proteins. The cellular functions of unknown proteins were estimated from the analysis of domain structure, expression profile and predicted interaction partners.

A Study of the Parameters of the Retention of Monosubstituted Benzenes in Reversed-Phase Liquid Chromatography

  • Lee Dai Woon;Yook Keun Sung;Kim Ho Seob;Lee Won
    • Bulletin of the Korean Chemical Society
    • /
    • v.10 no.1
    • /
    • pp.34-39
    • /
    • 1989
  • The relationship between the solute retention and physical parameters describing the interaction between the solute and mobile phase was investigated to predict the solute retention easily in RPLC. The retention data of monosubstituted benzenes were measured on the $\mu$-Bondapak C18 and phenyl columns with methanol-water systems. The linear relationship between dielectric increment($\epdilon'$) and retention data was observed. When the solute form hydrogen bonding with solvent molecules, the slope of the ln k' vs. $\epdilon'$ plot is changed as the compositions is varied. The quadric relationship between mixed solvent solubility parameter ($\delta$M) and retention data was observed.

  • PDF