Design of a Vitamin B₁‐Selective Electrode Based on an Ion‐Pair and Its Application to Pharmaceutical Analysis

Abstract

Vitamin B 1 -selective electrodes with PVC membrane were developed that contain ion associates of vitamin B 1 with an inorganic anion, BiI 4 À , and an organic anion, brilliant yellow, as electrode-active substances. The linearity ranges of the electrode function are 1.0 10 À5 -1.0 10 À2 and 1.0 10 À4 -1.0 10 À2 M, the electrode function slopes are 33.0 AE 1.0 and 33.1 AE 1.1 mV decade À1 , the detection limits are 5.5 10 À6 and 8.3 10 À5 M for BiI 4 À and brilliant yellow respectively. The working range of pH is 5-12. The efficiency of the use of electrodes for the vitamin B 1 content control in multivitamin pharmaceutical preparations was shown by direct potentiometry and potentiometric titration methods.