Analysis of heterocyclic amines as their N-dimethylaminomethylene derivatives by gas chromatography with nitrogen-phosphorus selective detection

A selective and sensitive method was developed for the determination of heterocyclic amines (HCAs) by gas chromatography (GC). HCAs were converted into their N-dimethylaminomethylene derivatives and measured by GC with nitrogen-phosphorus selective detection using two connected fused-silica capillary columns containing DB-1 and DB-17ht. The derivatives of the 10 HCAs were sufficiently volatile and stable to give single symmetrical peaks. The calibration curves for HCAs in the range 0.5-10 ng were linear with correlation coefficients being above 0.998. The detection limits at a signal-to-noise ratio of 3 were ca. 2-15 pg per injection.