Monitoring a potential carcinogen in pharmaceutical formulations at the low part per billion level. High-performance liquid chromatographic determination of N-nitrosohexamethyleneimine in tolazamide.

A method is described for the determination of N-nitrosohexamethyleneimine, a potential carcinogen, in tolazamide bulk drug and pharmaceutical dosage forms. The technique of trace enrichment high-performance liquid chromatography is employed to obtain accurate quantitation of the analyte at levels approaching 1 ppb. Following extraction in diethyl ether and on-line cleanup and enrichment, the nitrosamine is detected by UV at 228 nm.