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ABSTRACT: Microcolumn ion chromatography using anion exchangers modified with dextran sulfate has been applied to the determination of alkali and alkaline-earth metal ions contained in guinea pig serum and bovine serum. These serums contained Na+, NH4+, K+, Mg2+ and Ca2+ and they were indirectly detected at 200 nm. The determination was done without any pretreatment procedure other than dilution.
Journal of chromatography. B, Biomedical sciences and applications 05/2001; 753(2):409-12.
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ABSTRACT: Aluminum and magnesium were determined by fluorimetric detection via pre-column and/or in-column derivatization with 8-hydroxyquinoline (oxine) in high-performance liquid chromatography. The oxine complex of aluminum was selectively detected when the eluent contained no oxine, whereas the aluminum and magnesium complexes could be simultaneously detected when the eluent contained oxine. The sensitivity was improved by using eluents containing oxine by a factor of 7.1 for aluminum, and the detection limits at S/N=3 were 18 and 16 ng/ml for magnesium and aluminum, respectively. The present system was applied to the determination of magnesium and aluminum in various water samples.
Journal of Chromatography 04/2001; 910(2):373-6. · 4.53 Impact Factor
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ABSTRACT: The separation of enantiomers of chloroquine and other amine derivatives has been investigated by liquid chromatography using anion exchangers modified with heparin as the stationary phase. Modification and mobile phase conditions affected the separation of analytes. Separation of the chloroquine enantiomers could be achieved by using a buffer solution containing acetonitrile as the mobile phase.
Journal of Chromatography 01/2000; 864(1):25-30. · 4.53 Impact Factor
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ABSTRACT: Effect of eluent composition on retention behavior of inorganic anions have been investigated in ion chromatography using anion-exchangers modified with heparin. Both cation and anion of the eluent affected the retention of analyte anions and unusual retention behavior was observed on the modified stationary phase. The retention time of anions decreased with decreasing eluent concentration when sodium sulfate, magnesium sulfate and chlorides of alkali metals were used as the eluent, whereas it increased with decreasing eluent concentration when aluminum sulfate, copper sulfate and sulfuric acid were used as the eluent. The retention of nitrate increased in the order of Li+, Na+, K+, Rb+ and Cs+ when their chlorides were used as the eluent. When sodium perchlorate and chlorides of alkaline-earth metals were used as the eluent, the eluent should include heparin. Otherwise, the modifier was partially bled from the column.
Journal of Chromatography 08/1999; 850(1-2):65-72. · 4.53 Impact Factor
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ABSTRACT: Retention behavior of anions and cations on anion-exchangers modified with dextran sulfate has been investigated. Retention
of anions was remarkably reduced by the modification, and the retention factor decreased with decreasing eluent concentration
when sodium sulfate was used as the eluent. Cations were also retained on the modified stationary phase, and alkali and alkaline-earth
metal ions were separated using copper sulfate or tris(2,2′-bipyridyl)ruthenium chloride as eluent. The size of the dextran
sulfate strongly affected the retention behavior of analyte ions.
Chromatographia 06/1999; 50(1):70-74. · 1.20 Impact Factor
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ABSTRACT: Anion exchangers modified with mucopolysaccharides, such as chondroitin sulfates and heparin, were used for the stationary phase in ion chromatography. Unusual retention behavior of anions was observed for the modified stationary phases. A 50-microM concentration of tartaric acid could separate inorganic anions in a reasonable time. The retention of analytes could be changed by changing the eluent composition.
Journal of Chromatography 05/1998; 804(1-2):79-86. · 4.53 Impact Factor
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ABSTRACT: Octadecylsilica immobilized with bovine serum albumin was capable of separating inorganic anions. The stationary phase retained anions under acidic conditions, and the use of aqueous solution containing sodium iodide and tartaric acid as the eluent allowed the indirect photometric determination of chloride and nitrate in water and serum samples. The mobile phase conditions were optimized.
Journal of Chromatography 12/1996; 755(1):37-42. · 4.53 Impact Factor
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ABSTRACT: The retention behavior of dansyl amino acids in micellar liquid chromatography has been examined by using ionexchange-induced stationary phases. Several parameters affected the retention of the analytes, including the type and concentration of micellar agent and modifier ion and the concentration of acetonitrile in the mobile phase. The order of elution of dansyl amino acids obtained with the micellar mobile phase was very different from that observed in conventional reversed-phase liquid chromatography. Fluorescence intensities of some dansyl amino acids were enhanced by the micellar mobile phase.
Chromatographia 07/1996; 43(3):143-148. · 1.20 Impact Factor
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ABSTRACT: The effects of acetonitrile and bovine serum albumin (BSA) concentrations on the signal intensity and retention behavior of dansylamino acids have been examined by using -cyclodextrin-bonded silica gel as the stationary phase in microcolumn liquid chromatography. Fluorescence intensities of dansylamino acids were enhanced by BSA as a mobile phase additive, e.g., detection limits of dansyl derivatives of L-Ala and L-Phe were improved by a factor of 12–18.
Chromatographia 01/1995; 40(3):159-162. · 1.20 Impact Factor
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ABSTRACT: Retention behavior of inorganic anions and cations on anion exchangers modified with heparin has been investigated. Retention of anions on the anion exchanger was remarkably reduced after the modification with heparin. The cations of the eluent affected the retention behavior of ions. The retention factor of anions decreased with decreasing eluent concentration when sodium sulfate and magnesium sulfate were used as the eluent, whereas it increased with decreasing eluent concentration when aluminium sulfate, copper sulfate and sulfuric acid were used as the eluent. When copper sulfate was used as the eluent, both anions and cations were retained on the modified stationary phase and simultaneous separation of both anions and cations were carried out. Cations as well as non-UV-absorbing anions were indirectly visualized by copper ions.
http://dx.doi.org/10.1051/analusis:1998111.
