Determination of Vitamin B_1 in Pharmaceutical Preparations by Flow-injection Analysis with Biamperometric Detection

摘要

A new electrochemical method for the on-line determination of vitamin B,is presented.Based on dead-stop end-point biamperometry by using two platinum foil electrodes with an applied potential difference of 150 mV,vitamin B_1 can be oxidized by hexacyanoferrate(III)in a sodium hydroxide medium via a reversible indicating couple Fe(CN)_6~(4-)/Fe(CN)_6~(3-).The cell current is linear with the concentration of vitamin B_1 in the concentration range of 4.0 x 10~(-6)-1.0 x 10~(-3)mol/L with a detection limit of 8.0 x 10~(-7)mol/L(0.27 mug/mL).Most familiar excipients,ions and vitamins do not interfere with the determination of vitamin B_1.The method displays the advantages of simplicity,high efficiency(180 samples/h),and high selectivity,and is suitable for the determination of vitamin B_1 in pharmaceutical preparations.