Gas chromatographic separation of histamine and its metabolites

A new, rapid and simple gas-liquid chromatographic method is described for the simultaneous determination of histamine, 1-methylhistamine, 4-imidazoleacetic acid and 1-methyl-4-imidazoleacetic acid. These compounds are derivatized at 60 degrees in one fast 30-min reaction with bis(trimethylsilyl)acetamide-trimethylchlorosilane and are then separated on OV-17. No previous methylation of the acids is needed. A complete profile of the four metabolites can be obtained in 8 min with baseline resolution, and there are no tailing effects. The quantitative response curves are linear in the nanogram range, with detection limits of the order of 10 ng for the acids and 100 ng for the amines. The structures of these new trimethylsilyl derivatives have been verified by combined gas-liquid chromatography-mass spectrometry.