Clean-up procedures for the analysis of heterocyclic aromatic amines (aminoazaarenes) from heat-treated meat samples

The purpose of the study was to determine optimum conditions for the isolation and quantitation of five most biologically active aminoazaarenes {2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethyl-imidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)}. Some multistep procedures based on ultrasonic extraction, Soxhlet extraction, liquid–liquid extraction and solid-phase extraction (SPE) were tested in order to choose the optimum isolation conditions for aminoazaarenes from fried meat samples spiked with known amounts of standards. According to the tested methods the qualitative–quantitative analysis was performed on the unspiked sample of pork roasted in typical household conditions. The qualitative–quantitative analysis of the aminoazaarenes was performed by a HPLC method. A HPLC Hewlett-Packard HP 1090 liquid chromatograph equipped with a UV diode array detector (DAD) was used. Chemically bonded HPLC columns C8 and TSK-gel ODS 80-TM were used under gradient elution conditions. A two-component mixture containing triethylamine–phosphate buffer (pH 3.2 and 3.3) and acetonitrile was used as a mobile phase. The results of the studies showed that a solid-phase extraction procedure using diatomaceous earth (Extrelut, 20 ml), propylsulphonic acid (PRS, 500 mg) and octadecylsilane (C18, 500 mg) columns was the quickest and simplest one. Recoveries of the aminoazaarenes, spiked and isolated from meat samples by the chosen SPE procedure, were as follows: IQ 85%, MeIQ 50%, MeIQx 46%, 4,8-DiMeIQx 62%, PhIP 50%.