Differential pulse voltammetry at glassy carbon electrode for detection of thiamine at neutral pH

Quantitative detection of thiamine has been widely carried out by voltammetry technique in an alkaline solution. This study aims to develop a differential pulse voltammetry (DPV) technique for thiamine detection in a neutral solution using a glassy carbon electrode. The optimum conditions for thiamine detection are determined by varying several parameters, including pre-treatment potential, the period of pre-treatment, potential step, and potential pulse. The results indicated that the thiamine oxidation peak was detected at a potential of 0.03 V vs Ag/AgCl. The optimum conditions for thiamine detection in a neutral solution using the DPV method were obtained at a pre-treatment potential of -1700 mV vs Ag/AgCl, pre-treatment period of 10 s, a potential step of 25 mV, and a potential pulse of 200 mV. The developed thiamine detection method was provided by an acceptable analytical performance, including linearity (R²) of 0.9809 in.the linear range of 0.6 mM to 1.6 mM, the detection limit of 5.14×10⁻⁴ M, the quantitation limit of 1.71×10⁻³ M, and the precision (% RSD) of 4.46%. The developed thiamine detection method using the DPV technique is a potential method for the routine analysis of thiamine.