Chlorpromazine metabolism VII: new quantitative fluorometric determination of chloropromazine and its sulfoxide.

A new, sensitive assay is described for chlorpromazine and/or its sulfoxide. The method is based on reacting the tertiary amine base with 9-bromomethylacridine to form a quaternary compound which, on photolysis, yields highly fluorescent products that are determinable fluorometrically. The procedural steps were standardized, and an optimum assay procedure was developed. The method shows a less than 3% coefficient of variation when applied directly to chlorpromazine samples and is capable of determining 15-20 ng of the drug. The method is readily adaptable to clinical and bioavailability studies.