New method for the analysis of non-polar heterocyclic aromatic amines in beefburguers by using microwave-assisted extraction and dispersive liquid-ionic liquid microextraction

LEIDY B. AGUDELO MESA; JUAN M. PADRÓ; MARIO RETA

FOOD CHEMISTRY

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2013 vol. 141 p. 1694 - 1701

0308-8146

A new sample preparation procedure to determine six heterocyclic aromatic amines (2-amino-3-methylimidazo [4,5-f] quinoline, 2-amino-3,4-dimethylimidazo [4,5-f]-quinoline, 2-amino-3,8-dimethylimidazo [4,5-f] quinoxaline, 2-amino-1-methyl-6-phenylimidazo [4,5-b]-pyridine, 2-amino-9H-pyrido [2,3-b]-indole and 2-amino-3-methyl-9H-pyrido [2,3-b]-indole) in cooked beefburguers by using a combination of microwave-assisted solvent extraction and dispersive liquid-liquid microextraction with an ionic liquid generated in-situ was used. The optimized microwave extraction procedure consisted of a clean-up step with n-heptane and a subsequent dissolution step in basic media to desorb the analytes from the matrix. Next, an aqueous solution of the ionic liquid 1-octyl-3-methylimidazolium tetrafluorborate and sodium hexafluorphosphate was added and a water-insoluble 1-octyl-3-methylimidazolium hexafluorphosphate was formed within the matrix sample. The amines were analyzed by liquid chromatography with fluorescence and diode-array detection by using a typical C18 column. Peak identities were confirmed by absorbance spectral matching. Repeatability (RSD%) between 5.4 and 10.9%, enrichment factors between 19 and 30, limits of detection between 0.35-2.4 ng mL-1 and recoveries between 69 and 100% were achieved. The extraction methodology is simple, rapid (about 40 min/ sample) cheap and green since small amounts of non-toxic solvents are necessary.