Spectrophotometric Determination of Isoniazid in Pharmaceutical Sample by Silicomolybdenum Blue

Abstract

A novel method for the spectrophotometric determination of isoniazid by silicomoly- bdenum blue has been established.The various effect factors on the spectrophotometric determination of isoniazid by silicomolybdenum blue were investigated in detail.The results showed that under certain reaction conditions,silicomolybdenum yellow could be reduced to silicomolybdenum blue by isoniazid, and the content of isoniazid was determinated indirectly through determinating the absorbance of the silicomolybdenum blue. The maximum absorption wavelength of chromogenic system is 740 nm, good linear relationship is obtained between the absorbance and the concentration of isoniazid in the range of 1.968～27.55 μg/mL,and the equation of the linear regression is A=0.0247+61.824ρ (μg/mL) with a linear correlation coefficient is 0.9995.This proposed method has been successfully applied to determinate of isoniazid in isoniazid tablets, and the results agree well with those obtained by pharmacopoeial method.