Adsorptive stripping voltammetric study of vitamin B1 at multi-walled carbon nanotube paste electrode

The electrochemical response of vitamin B-1 at different types of carbon electrodes viz: glassy carbon electrode (GCE), carbon paste electrode (CPE), single walled carbon nanotube paste electrode (SWCNTPE) and multi walled carbon nanotube paste electrode (MWCNTPE) has been investigated using cyclic voltammetric (CV) and differential pulse adsorptive stripping voltammetric (DPAdSV) methods. A simple and selective differential pulse adsorptive stripping voltammetric method has been developed for the determination of vitamin B-1 in pure form and in pharmaceutical preparations. Various parameters that can influence the peak signal (effect of buffer, accumulation time, pH, scan rate, accumulation potential, and pulse amplitude) have been scrutinized. The best results were obtained in acetate buffer (pH 6.3) using multi-walled carbon nanotube paste electrode at a deposition time of 80 s, deposition potential of 0.0 V, scan rate of 50 mV s(-1) and pulse amplitude of 50 mV. The reduction peak current varies linearly with the concentration of vitamin B-1 over the range of 1.0 x 10(-7) - 1.0 x 10(-6) M. The limits of detection and quantification of the pure drug are 1.1 x 10(-10) Mand 2.0 x 10(-9) M, with the correlation coefficient, r=0.997 and the relative standard deviation, RSD = 1.2% (n = 5). Experimental results reveal that the MWCNTPE has advantages of small background current, high signal to background current ratio and good reproducibility. (C) 2013 Production and hosting by Elsevier B.V. on behalf of King Saud University.