Abstract

A capillary zone electrophoretic (CZE) method has been developed and optimized for the simultaneous determination of 2-amino-3,8-dimethylimidazo[4,5-f]quinoline (IQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f] quin-oxaline (4,8-DiMeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PHIP) in fried beefsteak, meat extract, and baked salmon. Solid-phase extraction (the Gross methodology) was tested for isolating the amines. Under optimum capillary electrophoresis conditions the proposed method separated heterocyclic aromatic amines (HAAs) within 20 min. Diode-array UV photometric detection was used and peak identities were confirmed by comparison of spectra. The limits of detection of the method were between 0.05 and 0.22 mu g mL(-1) with hydrodynamic injection, and from 0.08 to 0.16 mu g mL(-)1 with electrokinetic injection; injection reproducibility (RSD %) was better with pressure injection (4.7-7.9 %) than with electrokinetic injection (8.6-20.7 %). The method was applied to the analysis of real and spiked samples, recoveries ranged from 6 % for PHIP to 91 % for 4,8-DiMeIQx from various cooked foods.