| Abstract: | Capillary zone electrophoresis with end-column amperometric detection at a copper microdisk electrode (100 μm in diameter) was successfully applied for simultaneous determination of carbohydrates and amino acids. Under the separation voltage of 27 kV and the separation electrolyte of 80 mM NaOH in a 75 cm fused silica capillary (10 μm i.d. × 375 μmU o.d.), complete separation of a standard mixture containing 9 carbohydrates and 12 amino acids was achieved in less than 25 min. With the electrokinetical injection of 5.4 s at 27 kV and the detection potential of 0.62 V vs. Ag/AgCl, the detection limits (S/N = 3) were 0.22–0.65 ppm (1.2–1.9 μM) for carbohydrates and 0.31–6.5 ppm (2.3–39 μM) for amino acids, respectively. The calculated numbers of theoretical plates were between 41,000 and 190,000. The use of this method for analysis of carbohydrates and amino acids in a urine sample was demonstrated. |
