Analysis of heterocyclic aromatic amines by high resolution gas chromatography-mass spectrometry: a suitable technique for the routine control of food and process flavours

Ten heterocyclic aromatic amines (HAA; [2amino-3-methyl-3H-imidazo[4,5-f]qu inoline (1): 2-amino-3,4-dimethyl-3H-imidazo[4,5-f]quinoline (2); 2-amino-3 -methyl-3H-imidazo[4,5-f]quinoline (3); 2-amino-3.8-dimethyl-3H-imidazo [4, 5-f]quinoline (4); 2-amino3,4,8-trimethyl-3H-imidazo[4,5-f]quinoline (5); 2 -amino-3.7,8-trimethyl-3H-imidazo [4,5-f]quinoline (6) 2-amino-3,4,7,8-tetr amethyl-3H-imidazo[4,5-f]quinoline (7); 2-amino-1-methyl-6-phenyl-imidazo[4 ,5-f]quinoline (8); 2-amino-6-methyldipyrido[1,2-alpha:3',2'-d]imidazole (9 ); 2-aminodipyrido[1,2-alpha:3',2'-d] imidazole (10)]) were analysed in com mercially available meat products and process flavours. After sample prepar ation by Extrelut treatment, subsequent solid phase extraction applying pro pylsulphonic and C-18 silica cartridges, as well as derivatization with 3,5 -bis-trifluoromethylbenzyl bromide, HRGC-electron-impact-ionization-MS (HRG C-EIMS) analysis in the selected ion monitoring mode was performed. Isotope dilution analysis with 2-amino-8-methyl-3-(trideuteromethyl)-3H-imidazo[4, 5-f]quinoxaline and 2-amino-1-(trideuteromethyl)-6-phenyl-imidazo[4,5-b]pyr idine was used to quantify 4 and 8; for 1-3, 5-7, 9 and 10, standard additi on was employed as the determination method. The detection limit of 1 ng/g evaluated for 3-6 and 9 was sufficient for routine analysis, i.e. to obtain an initial insight into the grade of a potential HAA contamination of food or process flavours. To obtain more detailed information, the previously d eveloped, more sensitive technique of HPLC-electrospray-tandem-MS (HPLC-ESI -MS/MS) has to be used, as shown by the comparison of the data obtained by HRGC-MS and HPLC-ESI-MSIMS analyses.