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Histidine‐functionalized silica and its copper complex as stationary phases for capillary electrochromatography
Author(s) -
Chen TseShien,
Liu ChuenYing
Publication year - 2001
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/1522-2683(200107)22:12<2606::aid-elps2606>3.0.co;2-i
Subject(s) - capillary electrochromatography , chemistry , copper , benzoic acid , electron paramagnetic resonance , histidine , silica gel , electrochromatography , inorganic chemistry , capillary electrophoresis , chromatography , organic chemistry , physics , nuclear magnetic resonance , enzyme
A histidine‐functionalized silica was prepared by covalent bonding of the functional groups to silane‐treated silica gel. Conversion of functional groups was confirmed by infrared (IR) spectra, elemental analysis, and potentiometry. The functionality of the silica gel is 0.293 mmol g –1 . The coordination behavior of the histidine‐functionalized silica was investigated by metal capacity and electron paramagnetic resonance (EPR). EPR measurements at different copper loadings were made. The results showed that the copper histidine complex might be distorted tetragonal. Both histidine‐functionalized silica and its copper complex were employed as stationary phases for packed capillary electrochromatography (CEC). Electrical current was found helpful for evaluating the properties of frit construction and the stationary phase packing. Test samples include neutral compounds, inorganic anions and organic anions. Factors influencing the separation behavior have been studied. With copper‐histidine functionalized silica under the condition of citrate buffer (10 m M , pH 4.0) and applied voltage of –20 kV, the separation of benzoic acid, D ‐ and L ‐mandelic acid, phthalic acid and salicylic acid could be achieved within 12 min. The column efficiency for these acids was more than 1.2×10 5 plates m –1 , except salicylic acid.