Glutathione conjugation of arylnitroso compound: detection and monitoring labile intermediates in situ inside a fast atom bombardment mass spectrometer.

The glutathione (GSH) conjugation reaction of the active metabolite of a potent protein-pyrolysate carcinogen, 2-nitroso-6-methyldipyrido[1,2-a:3',2'-d]imidazole (NO-Glu-P-1), occurred in glycerol matrix inside a fast atom bombardment (FAB) mass spectrometer. The short lived GSH-conjugates were detected by in situ FAB analysis. The precursor-product relationship between the conjugates was indicated by following the reaction by measuring [M + H]+ ions of the conjugates.