ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Capillary electrophoresis of herbicides. III. Evaluation of octylmaltopyranoside chiral surfactant in the enantiomeric separation of phenoxy acid herbicides (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 8 (1996), S. 518-524 
    Details
    ISSN: 0899-0042
    Keywords: chiral capillary electrophoresis ; chiral micelle ; phenoxy acid herbicides ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A chiral alkylglucoside surfactant, namely n-octyl-β-D-maltopyranoside (OM), was evaluated in the enantiomeric separation of phenoxy acid herbicides. The enantiomeric resolution of the phenoxy acid herbicides could be manipulated readily by adjusting the surfactant concentration, ionic strength, pH, the percent organic modifier and separation temperature. The optimum surfactant concentration needed for maximum enantiomeric resolution varied among the different analytes, and was an inverse function of the hydrophobicity of the phenoxy acid herbicides with the most hydrophobic solute requiring less surfactant concentration for attaining a baseline enantiomeric resolution. Due to the ionic nature of the phenoxy acid herbicides, increasing the pH of the running electrolyte increased the degree of ionization of the acidic herbicides thus decreasing their association with the chiral micelles and in turn their enantiomeric resolution. Increasing the ionic strength of the running electrolyte seems to enhance both the solubilization of the solute in the micelle and the chiral interaction of the solute with the micelle with a net increase in enantiomeric resolution. The percent of added methanol had a varying effect on the resolution of the various enantiomers in the sense that it enhanced the enantiomeric resolution for the most hydrophobic solutes while it decreased the enantiomeric resolution for the weakly hydrophobic ones. Thermostating the capillary column at subambient temperature improved enantiomeric resolution. © 1996 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 2
    Electronic Resource
    Electronic Resource
    Capillary electrophoresis of carboxylated carbohydrates. Part 2. Selective precolumn derivatization of sialooligosaccharides derived from gangliosides with 7-aminonaphthalene-1,3-disulfonic acid fluorescing tag (1995)
    Weinheim : Wiley-Blackwell
    Electrophoresis 16 (1995), S. 1499-1504 
    Details
    ISSN: 0173-0835
    Keywords: Capillary electrophoresis ; Sialooligosaccharides ; Gangliosides ; Precolumn derivatization ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: The most suitable conditions for selective precolumn derivatization of sialooligosaccharides, derived from gangliosides, with 7-aminonaphthalene-1,3-disulfonic acid (ANDSA) and the subsequent separation of the derivatives by capillary electrophoresis are described. ANDSA-sialooligosaccharide derivatives, which fluoresce at 420 nm when excited at 315 nm, were readily detected in capillary electrophoresis using an on-column lamp-operated fluorescence detector. In addition, the precolumn derivatization described here, which exploited the reactivity of the carboxylic acid group of the sialic acid residue of the oligosaccharides, replaced each weak carboxylic acid group of the parent sugar by two strong sulfonic acid groups. This allowed for electrophoresis over a wide range of pH and improved the resolution of the derivatives when compared to those obtained with underivatized sialooligosaccharides under identical separation conditions. The separation of sialooligosaccharides was best achieved when 75 mM borate, pH 10.0, was used as the running electrolyte. The derivatization and separation conditions described herein are expected to be readily transposed to the capillary electrophoresis of other sialooligosaccharides such as those derived from glycoproteinsPresented partially in a lecture (M-L7) at the Fourth International Symposium Workshop on Bioanalysis, Lawrence, KS, July 10-13, 1994 and as part of a lecture at Electrophoresis Forum '94, Munich, Germany, October 24-26, 1994. Part I is reference [9]..
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elps.11501601248
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Recent advances in capillary electrophoresis of carbohydrates (1996)
    Weinheim : Wiley-Blackwell
    Electrophoresis 17 (1996), S. 275-301 
    Details
    ISSN: 0173-0835
    Keywords: Capillary electrophoresis ; Carhohydrates ; Glycoproteins ; Glycoforms ; Glycopeptides ; Glycosaminoglycans ; Glycolipids ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elps.1150170203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Capillary electrophoresis of herbicides: IV. Evaluation of octylmaltopyranoside chiral surfactant in the enantiomeric separation of fluorescently labeled phenoxy acid herbicides and their laser-induced fluorescence detection (1997)
    Weinheim : Wiley-Blackwell
    Electrophoresis 18 (1997), S. 220-226 
    Details
    ISSN: 0173-0835
    Keywords: Chiral capillary electrophoresis ; Phenoxy acid herbicides ; Precolumn derivatization ; Laser-induced fluorescence ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: A novel chiral nonionic surfactant, namely octyl-b-D-maltopyranoside (OM), was evaluated in chiral capillary electrophoresis of fluorescently labeled phenoxy acid herbicides. The labeling of the analytes with 7-aminonaphthalene-1,3-disulfonic acid (ANDSA) permitted a concentration detection limit of 5 × 10-10 M using laser-induced fluorescence detection. This limit of detection allowed the determination of ultradiluted solutions of the ANDSA-derivatized phenoxy acid herbicides whose concentration was as low as 10-11 M (i.e. 2.2 ppt) by applying the concept of field-amplified sample stacking (FASS). The sample injection by FASS did not adversely affect separation efficiencies, resolution and reproducibility of the electroporetic system. The tagging of the phenoxy acid herbicides with ANDSA increased the hydrophobicity of the analytes, thus favoring an enhanced solubilization of the derivatized herbicides in the OM micellar phase. The net results of this effect were a much shorter analysis time and an improved enantiomeric resolution of the derivatives when compared to underivatized phenoxy acid herbicides. The optimum surfactant concentration required for maximum resolution decreased with increasing hydrophobicity of the analyte, with the least hydrophobic analyte requiring higher surfactant concentration. Because of the two permanently charged sulfonic acid groups of the ANDSA tag, the pH of the running electrolyte had little effect on the enantiomeric resolution of the derivatized herbicides. Due to its salting-out effect and increasing the micellized surfactant concentration, increasing the ionic strength of the running electrolyte increased the enantiomeric resolution of the least hydrophobic analytes. Conversely, increasing the percent methanol in the running electrolyte decreased the enantiomeric resolution of the least hydrophobic analytes due to decrease strength of solute-micelle association. For hydrophobic analytes, existed an optimum percent of methanol existed for maximum enantiomeric resolution.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elps.1150180208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Comparison of alkylglycoside surfactants in enantioseparation by capillary electrophoresis (1997)
    Weinheim : Wiley-Blackwell
    Electrophoresis 18 (1997), S. 912-918 
    Details
    ISSN: 0173-0835
    Keywords: Chiral capillary electrophoresis ; Alkylglycoside surfactants ; Dansyl amino acids ; Warfarin ; Bupivacaine ; Binapthyldiylhydrogen phosphate ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Three alkylglycoside surfactants, namely n-octyl-β-D-glucopyranoside (OG), n-nonyl-β-D-glucopyranoside (NG), and n-octyl-β-D-maltopyranoside (OM), were compared in the enantiomeric separation of dansyl amino acids, binaphthyl phosphate, bupivacaine and warfarin. While only OM exhibited an enantioselectivity toward warfarin, bupivacaine, and dansyl tryptophan, all three surfactants were effective in the enantiomeric resolution of napthyl phosphate and other dansyl amino acids. With the exception of naphthyl phosphate, which could be resolved enantiomerically with OM at surfactant concentrations below the CMC, all solutes required surfactant concentrations greater than the CMC value. This was attributed to the strong hydrophobic association of napthyl phosphate with the OM monomers and to the presence of maltoside residue in the OM surfactant. In general, the optimum surfactant concentration needed for maximum enantiomeric resolution was an inverse function of the hydrophobic character of the solute. Under a given set of conditions, the enantiomeric resolution exhibited by the alkylglycoside surfactants was largely influenced by the extent and loci of solute solubilization into the micelle, and by the nature of the chiral sugar head group of the surfactant.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elps.1150180610
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Capillary zone electrophoresis of derivatized acidic monosaccharides (1994)
    Weinheim : Wiley-Blackwell
    Electrophoresis 15 (1994), S. 627-634 
    Details
    ISSN: 0173-0835
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: A new and specific precolumn derivatization reaction for acidic monosaccharides was introduced and evaluated in the separation and sensitive detection of carbohydrates by capillary electrophoresis. The derivatization reaction involved the attachment of sulfanilic acid (a UV absorbing tag) or 7-aminonaphthalene-1,3-disulfonic acid (a UV absorbing and fluorescing tag) via a condensation reaction between the amino group of the derivatizing agent and the carboxyl group of the sugar in the presence of a water-soluble carbodiimide. The derivatization reaction replaced the weak carboxylic acid of the sugar by a strong sulfonic acid, which is fully ionized at all pH. This allowed the electrophoresis of the sugar derivatives over a wide pH range and permitted the determination of acidic carbohydrates at very low femtomole levels by UV and fluorescence detection.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elps.1150150187
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Capillary enzymophoresis of nucleic acid fragments using coupled capillary electrophoresis and capillary enzyme microreactors having surface-immobilized RNA-modifying enzymes (1995)
    Weinheim : Wiley-Blackwell
    Electrophoresis 16 (1995), S. 2164-2171 
    Details
    ISSN: 0173-0835
    Keywords: Capillary electrophoresis ; Capillary enzymophoresis ; tRNA ; Dinucleotides ; RNA modifying enzymes ; Immobilized enzymes ; Capillary enzyme reactor ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: This report describes the coupling of capillary enzyme reactors to capillary electrophoresis, which is termed capillary enzymophoresis. In the present study, the capillary enzyme reactors were prepared by immobilizing RNA-modifying enzymes, e.g., RNase T1 and RNase U2, on the inner walls of 50 μm fused-silica capillaries. These microreactors served to selectively modify the solutes (or substrates) before entering the separation capillary. Capillary enzymophoresis using single or mixed enzyme reactors proved useful in identifying minute amounts of dinucleotides as well as the fingerprinting of tRNAs. The immobilized RNase T1 and RNase U2 displayed their usual enzymic activities toward RNA fragments and in addition exhibited different activity-pH dependency than the soluble enzymes. This was attributed to microenvironmental effects arising from the charged nature of the capillary walls in the close proximity of the immobilized enzymes. The enzyme reactors were reusable for several RNA samples and showed chemical and thermal stabilityPresented as a part of a lecture (#313) at Pittsburgh Conference 94 (Pittcon '94), Chicago, Illinois, February 27-March 4, 1994..
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elps.11501601349
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Fused-silica capillaries with surface-bound dextran layer crosslinked with diepoxypolyethylene glycol for capillary electrophoresis of biological substances at reduced electroosmotic flow (1995)
    Weinheim : Wiley-Blackwell
    Electrophoresis 16 (1995), S. 617-624 
    Details
    ISSN: 0173-0835
    Keywords: Capillary electrophoresis ; Capillary coating ; Proteins ; Acidic monosaccharides ; Sialooligosaccharides ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: This report is concerned with the introduction of novel surface modification involving the covalent attachment of branched, high molecular weight dextrans and subsequent crosslinking with polyether chains on the inner surface of fused silica capillaries with the aim of producing hydrophilic capillaries with reduced electroosmotic flow (EOF). Three different molecular mass dextrans, namely 45, 71 or 150 kDa were covalently attached to the capillary surface, and subsequently crosslinked with diepoxypolyethylene glycol (PEG). This chemistry produced stable coating over a wide range of conditions including high and low pH aqueous solutions. Moreover, the various dextran-PEG-coated capillaries exhibited reduced electroosmotic flow. These features of the dextran-PEG coatings were useful for the separations of basic and acidic proteins, and provided high resolution separation for closely related acidic monosaccharides and sialooligosaccharidesPresented as a poster at Electrophoresis Forum '94, Munich, Germany, October 24-26, 1994.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elps.1150160199
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    facet.materialart.
    Unknown
    Assigning N-Glycosylation Sites of Glycoproteins Using LC/MSMS in Conjunction with Endo-M/Exoglycosidase Mixture (2010)
    American Chemical Society
    Details
    Publication Date: 2010-07-02
    Print ISSN: 1535-3893
    Electronic ISSN: 1535-3907
    Topics: Chemistry and Pharmacology
    Published by American Chemical Society
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    N-Linked Glycan Profiling in Neuroblastoma Cell Lines (2015)
    American Chemical Society
    Details
    Publication Date: 2015-03-16
    Print ISSN: 1535-3893
    Electronic ISSN: 1535-3907
    Topics: Chemistry and Pharmacology
    Published by American Chemical Society
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...