Spectrophotometric Determination of Chlorocresol via Nitrosation Reaction – Application to Pharmaceutical Preparations (Creams)


A spectrophotometric method for the determination of pure chlorocresol and in a number of its pharmaceutical preparations (creams) has been developed that offers advantages of simplicity, sensitivity and stability. The proposed method was based on the formation of a nitroso derivative of chlorocresol. The colored product have maximum absorption at 424 nm. Beer's law is obeyed over the concentration range of (2-26) ppm, with a molar absorptivity of 0.417×104 l.mol-1.cm-1. Relative standard deviation of the method was better than ±1.8% and the average recovery was 99.2%. The proposed method has been successfully applied to the determination of chlorocresol in pure form and in pharmaceutical preparations (creams).