Simple methods for quantifying mutagenic heterocyclic aromatic amines in food products.

Two solid-phase extraction methods were developed for the determination of mutagenic heterocyclic aromatic amines in heated meat products. The copper phthalocyanine (CPC) tandem extraction was performed on coupled cartridges of diatomaceous earth and CPC-derivatized Sephasorb HP, followed by further clean-up on Sephasorb HP. Parts per billion levels of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and its homologs as well as 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), amino-alpha-carboline (A alpha C), 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), harman (H) and norharman (NH) can then be simultaneously quantified by HPLC with UV detection. The propylsulfonyl silica gel (PRS) tandem extraction is a one-step clean-up method on coupled cartridges of diatomaceous earth and PRS, suitable for the determination of MeIQx, IQ and their homologs, as well as the glutamic acid pyrolysates 2-amino-6-methyldipyrido[1,2-a:3',2']imidazole (Glu-P-1) and 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2). 4,7,8-TriMeIQx or 7,8-DiMeIQx were used as internal standards. Four grams of sample or less are required for analysis. The recovery of the amines was between 46 and 83% and the detection limit was in the low p.p.b. range with coefficients of variation ranging between 5 and 18%. The major mutagenic contaminant found in meat extracts was MeIQx (from less than 1 to 44 p.p.b.), followed by 4,8-DiMeIQx (1.3-5 p.p.b.) whereas the major contaminant in fried meat was PhIP (23-48 p.p.b.), followed by MeIQx (5.1-8.3 p.p.b.), A alpha C (3.2-8.9 p.p.b.) and 4,8-DiMeIQx (1.3-2 p.p.b.). The co-mutagens NH and H were found in fried meat at levels of 8.7-19 p.p.b. and 3-4.8 p.p.b. respectively.