Application of renewable silver amalgam annular band electrode to voltammetric determination of vitamins C, B1 and B2

In this work, the design and results of applying silver liquid amalgam film–modified silver solid amalgam annular band electrode (AgLAF–AgSAE), refreshed before each measurement, to voltammetric determination of vitamins C (VC), B1 (VB1) and B2 (VB2) are presented. The method is based on adsorptive accumulation of analytes at the AgLAF–AgSAE in a phosphate buffer (VB1), phosphate buffer with Triton X-100 (VB2) and an alkaline borate buffer with Triton X-100 (VC). The analytical parameters and procedure of electrode activation were optimized. The calibration graphs obtained for vitamins C, B1 and B2 are linear, respectively, for concentration range 0.05–12, 0.01–0.1 and 0.05–3 mg L−1. The detection limits were calculated and equaled 0.02, 0.003 and 0.009 mg L−1, while repeatability of the peak current was 2%, 1% and 3%, respectively. These results are comparable with results obtained for polarographic determination of the same vitamins using mercury electrodes. Finally, the AgLAF–AgSAE was applied to the determination of vitamins in pharmaceutical samples and fruit juices with satisfactory results.