Preparation and Characterization of New Ion Selective Electrode for Determination of Vitamin B1

Abstract

A simple and rapid electrochemical sensor has been developed to determine the concentration of Thiamin hydrochloride (vitamin B₆). This method is based on the ion exchange complex of the Thiamin hydrochloride with zinc chloride as ion pair in paste carbon electrode, and Di-Butyl phthalate as a plasticizer.The electrode shows a Nernstian response within a range of concentrations (9.47×10^-6-1×10^-2) mol/L within a temperature range of (25-35)⁰C and a pH range of pH(4-6). It gave a Nernstian slope of 28.715 mv/decade, a response time of60. It was also shown by calculating selectivity coefficients using Matched potential method that the proposed electrode shows high selectivity for vitamin B₁ in the presence of a number of interfering ions (B₆,B₁₂,Cu²⁺,K⁺,Na⁺,Zn²⁺).

The low values of standard deviation and relative standard deviation indicated the precision of the method. Furthermore, the recovery values, which ranged between 96.10% and 103.00%, demonstrated the accuracy of the method The concentration of vitamin B₁ in some pharmaceutical preparations was determined using the proposed method, giving a recovery of  of 98.31% and 97.80% of the true value, with a detection limit of 1.78×10⁻⁶ mol/L. The results were compared with those obtained from a reference method, and based on the calculation of the F-test and Student’s t-test, good agreement was observed between the two methods. Therefore, the proposed selective electrode can be adopted as a potentiometric method for the determination of vitamin B₁. The proposed method was compared with other reference methods based on the same technique, and it was observed that this method also competes with several others in terms of detection limit, Nernstian slope, and linear range.