DETERMINATION OF AROMATIC-AMINES ORIGINATING FROM AZO DYES BY HYDROGEN PALLADIUM REDUCTION COMBINED WITH GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

Procedures were evaluated for reductive cleavage of eight commercial a zo dyes using hydrogen and palladium. The reduction was accomplished d irectly in a heated injector of a gas chromatograph (GC) with the resu lting products separated by a capillary gas chromatography (GC) and ch aracterized with a mass spectrometer (MS). This method resulted in nea rly complete reduction of the azo bond to form aromatic amines. Standa rds of the formed reduction products, when available, were employed to confirm identities. For most of the tested azo dyes, the in-line H-2- Pd reduction/analysis procedure yielded the same or a greater number o f reduced cleavage products than did reduction with SnCl2 in solution. The in-line reduction process was not affected by the presence of was tewater matrices. The GC/MS analysis of reduced waste sludge extracts indicated the presence of identifiable aromatic amines originating fro m the reduction of unknown dye components as well as other reducible n itrogen-containing compounds. While the identities of the parent dyes in these sludges were unknown, this analytical approach appears to pro vide a means to assess environmental significance of released effluent , based on the detection of potentially genotoxic aromatic amines.