铁氰化钾分光光度法测定药物中维生素B_1含量

Spectrophotometric Determination of Vitamin B_1 in Medicine with Potassium Ferricyanide

在NaOH碱性介质中,维生素B1能将K3[Fe（CN）6]定量还原为K4[Fe（CN）6],根据Fe3＋与K4[Fe（CN）6]反应生成可溶性普鲁士蓝的吸光度值,可间接测定出维生素B1的含量。在选定条件下,维生素B1在0.40~15.0mg·L-1范围内与吸光度（A）呈线性关系,相关系数R=0.9989,检出限为0.12mg·L-1,相对标准偏差（RSD）为1.75%（n=6）。表观摩尔吸光系数ε=4.3×104 L·mol-1·cm-1。该方法可用于药物中维生素B1含量的测定。

In an alkaline solution of NaOH, K3 [Fe（CN） 6 ] was quantitatively reduced to K4 [Fe（CN）6 ] by vitamin B1 and K4 [Fe（CN）6] reacted with Fe3＋ forming a soluble Prussian blue. The absorbance of soluble Prussian blue was measured at its absorption maximum of 704 nm and the amount of vitamin B, could be indirectly determined. Under optimized conditions, a good linear relationship was obtained in the range of 0.40-15.0 mg.L-1 of vitamin B, with a correlation coefficient of 0. 9989. The detection limit and relative standard deviation were 0.12 mg. L-1 and 1.75 %, respectively. The apparent molar absorption coefficient was 4.3 × 10-4 L, mol-. cm-1. This method has been successfully applied to the determination of vitamin B1 in medicine.