Rapid Colorimetric Method for the Quantitative Determination of Librium (Chlordiazepoxide Hydrochloride) in Serum

Abstract

A rapid, precise, and sensitive colorimetric method for determining Librium (chlordiazepoxide hydrochloride) in serum is described. The method is based upon extraction of Librium with chloroform and hydrolytic cleavage of the drug to an aromatic amine. The amine is diazotized and coupled with N-(l-naphthyl)-ethyl-enediamine to form a chromogen which follows Beer’s law at 550 nm. with Librium concentrations of as much as 4.0 mg. per 100 ml. Of more than 20 commonly used drugs that were evaluated as possible sources of interference, only sulfanilamide and procainamide were found to interfere with the proposed method for Librium. The coefficient of variation exhibited by the method is 7%.