Determination of adenine and guanine by capillary zone electrophoresis with end‐column amperometric detection at a carbon fiber microdisk array electrode

Capillary zone electrophoresis was employed to the analysis of adenine and guanine by using end‐column amperometric detector with a carbon fiber microdisk array electrode. Optimum conditions of separation and detection are 0.01 mol/L H3PO4–0.01 mol/L H3BO3–0.01 mol/L HAc‐NaOH (pH 9.2) for the buffer solution, 20 kV for the separation voltage, 3.0 kV and 5 s for injection voltage and time, respectively, and 1.00 V (vs.SCE) for the detection potential. The limit of detection is 8.2 fmol for adenine and 2.9 fmol for guanine (S/N = 2). The method was applied to determination of adenine and guanine in hydrolytic product of yeast‐RNA and calf thymus‐DNA.