Determination of purine bases by capillary zone electrophoresis with wall-jet amperometric detection

A new and sensitive method for the simultaneous determination of purine bases using capillary zone electrophoresis with vertical wall-jet amperometric detection was developed. The separation of adenine, guanine, hypoxanthine, xanthine and uric acid was performed in an uncoated silica capillary (50cm × 25 μm i.d.). A bundle of carbon fibers was used to fabricate the working electrode and the assay was optimized with respect to detection potential, pH and buffer concentration. The dependence of peak heights for these purine bases on their concentrations from 1.0 fmol to 0.2 pmol was linear. Under optimized conditions, the proposed method has been applied to analyze salmon testes DNA and human plasma with satisfactory results.