Simultaneous determination of 2-aminothiazole, 2-aminobenzothiazole and 2-mercaptobenzothiazole by capillary electrophoresis with end-column amperometric detection

Capillary electrophoresis with amperometric detection is evaluated for the simultaneous determination of 2-aminothiazole (A), 2-amino-benzothiazole (A B), 2-mercaptobenzothiazole (AM). The cyclic voltammogram, hydrodynamic vol tammogram, effect of pH, concentration of buffer and separation voltage on the separation and the detection were studied. The conditions were optimize d as follows: 50 mM phosphate buffet; pH 6.0, 2s at 17.5 kV sample injectio n, separation at 17.5 kV, 1.2 V as detection potential. The method provided low detection limit as 0.5 mu M, 0.05 mu M and 0.01 mu M, wide linear rang e 2-200 mu M, 10-200 mu M and 0.025-100 mu M for A, AB, and AM, respectivel y. The variations in peak current and migration time for 15 consecutive inj ections of a standard containing 5 mu M each compound were 3.7, 2.1, and 3. 9%, and 1.2, 0.8, and 1.2%, for A, AB and AM, respectively. This method was employed to analyze river water.