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Reverse Phase (reverse + phase)

Distribution by Scientific Domains
Chemistry75%

Terms modified by Reverse Phase

  • reverse phase hplc
    		•

    Selected Abstracts

    Extraction and purification of the zwitterions cylindrospermopsin and deoxycylindrospermopsin from Cylindrospermopsis raciborskii

    ENVIRONMENTAL TOXICOLOGY, Issue 5 2001
    R. L. G. Norris
    Abstract The hepatotoxin cylindrospermopsin (CYN) has been isolated from the cyanobacterium Cylindrospermopsis raciborskii (C. raci.). Efforts to study this toxin have been hampered by the time-consuming requirement to extract it from cultures of the organism. It is usually extracted from lyophilized cells collected from a laboratory culture. Our preliminary work suggested far more of the toxin is available in solution in the culture media than in the cells collected. We have therefore investigated the use of commercially available solid phase extraction sorbents to extract CYN from culture media in which C. raci. has been grown. A range of reverse phase and ion-exchange sorbents were tested across a range of pHs for their ability to retain CYN without success. Subsequently, graphitized carbon cartridges were found to retain CYN strongly. Elution with 5% formic acid in methanol allowed the CYN to be regained for final purification by HPLC. Deoxy-CYN, an analog of CYN can also be extracted using this procedure. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 391,396, 2001 [source]

    Isolation and Identification of Bitter Peptides of Tryptic Hydrolysate of Soybean 11S Glycinin by Reverse-phase High-performance Liquid Chromatography

    JOURNAL OF FOOD SCIENCE, Issue 8 2003
    I M.-R.
    ABSTRACT: The 21 peptides purified from the bitter fraction of tryptic hydrolysates of soybean 11S glycinin by using gel-permeation high-performance liquid chromatography (HPLC) and a series of 3 C18 reverse phase (RP)-HPLC were in the molecular weight range of 200-1400 Da and showed mostly the hydrophobicity of less than 1400 cal/mol. Although the primary structures of the bitter peptides from 11S glycinin were not exactly the same as those of the proglycinin, many bitter peptides were basic mimics of the common structure, indicating the significance of the primary structure of a peptide playing a role in the bitter taste perception. [source]

    Multidimensional chromatography coupled to mass spectrometry in analysing complex proteomics samples

    JOURNAL OF SEPARATION SCIENCE, JSS, Issue 10 2010
    Péter Horvatovich
    Abstract Multidimensional chromatography coupled to mass spectrometry (LCn -MS) provides more separation power and an extended measured dynamic concentration range to analyse complex proteomics samples than one dimensional liquid chromatography coupled to mass spectrometry (1D-LC-MS). This review gives an overview of the most important aspects of LCn -MS with respect to optimizing peak capacity and evaluate orthogonality. We review recent developments in LCn -MS to analyse proteomics samples from the analyst point of view and give an overview over methods and future developments to process LCn -MS data for comprehensive differential protein expression profiling. Examples from our research, such as combining protein fractionation using high temperature reverse phase (RP) columns followed by analysis of the trypsin-digested fractions by RP LC-MS, serve to highlight possibilities and shortcomings of present-day approaches. Other LCn -MS systems that have been used to analyse highly complex shotgun proteomic samples, such as the combination of RP columns using low and high pH eluents or the combination of hydrophilic interaction liquid chromatography (HILIC) with RP-MS is discussed in detail. [source]

    Preparation and enantioseparation characteristics of two chiral stationary phases based on mono(6A -azido-6A -deoxy)-perphenylcarbamoylated ,- and ,-cyclodextrin

    CHIRALITY, Issue 9 2004
    Xiang-Hua Lai
    Abstract Two chiral stationary phases, ph-,-CD and ph-,-CD, were prepared from mono(6A -azido-6A -deoxy)perphenylcarbamoylated ,- and ,-cyclodextrin immobilized onto silica gel via the Staudinger reaction. The chromatographic characteristics of these two chiral stationary phases were evaluated. The influence of different cyclodextrins (CDs) on the enantioselectivities was also investigated in this study. Compared to ph-,-CD, ph-,-CD exhibited quite good enantioselectivity toward the analytes with bulky molecular structures. It was found that the formation of inclusion complex might play a quite important role in the chiral recognition not only under reverse phases but also under normal phases. Chirality 16:592,597, 2004. © 2004 Wiley-Liss, Inc. [source]