A new quick solid-phase extraction method for the quantification of heterocyclic aromatic amines

A new solid-phase extraction (SPE) method using only one SPE cartridge is described as clean-up procedure for the determination of heterocyclic aromatic amines (HAAs). In particular, the polar HAAs imidazoquinolines and imidazoquinoxalines, which are well-known toxic compounds in thermally treated food, can be determined by this quick and simple method. For validation of the method meat extracts were analyzed. For determination of the percentage recovery and standard deviation the beef extract was spiked (40 ng/g of each HAA) and analyzed 10 times. The polar HAAs were determined in this meat extract with a recoveries of 62% to 95% and standard deviations of 3% to 5%. The recovery rates of the less polar HAAs Harman and Norharman were much lower (25 +/- 5% to 32 +/- 5%). The limit of detection for polar and less polar HAAs was between 3 ng/g and 9 ng/g in the meat extract matrix. The method comprises extraction with methanolic NaOH, centrifugation and SPE using a commercially available polystyrene copolymer cartridge. After different washing steps the eluate was analyzed by high-performance liquid chromatography with diode-array detection. The advantages of this new method are the reduced amounts of time and organic solvents required.