LIQUID-CHROMATOGRAPHY ATMOSPHERIC-PRESSURE CHEMICAL-IONIZATION MASS-SPECTROMETRY AS A ROUTINE METHOD FOR THE ANALYSIS OF MUTAGENIC AMINES IN BEEF EXTRACTS

A liquid chromatography-mass spectrometry (LC-MS) method using atmosph eric-pressure chemical ionisation as interface was developed for the s imultaneous determination of 14 heterocyclic aromatic amines and relat ed compounds in beef extracts. The separation was performed on a conve ntional C-18 column using a binary mobile phase composed of acetonitri le and 50 mM ammonium acetate at pH 5.7, and elution was carried out i n gradient mode. Several parameters influencing the mass spectra were optimized, and the effect of the variation of cone voltage on the mass spectra was studied. The [M+H](+) ions and some fragments produced in the source were observed in the mass spectra when several extraction voltages were applied. Quality parameters (run-to-run and day-to-day r eproducibility, intervals of linearity, and limits of detection) were studied in the optimum working conditions. The method was used to anal yze the heterocyclic amines present in a commercial beef extract. Ther efore, a solid-phase extraction clean-up procedure was performed prior the LC-MS analysis due to the complexity of the sample and the compou nds Glu-P-1, Harman, Norharman and A alpha C were identified in the sa mples at ppb levels and successfully confirmed using in-source fragmen tation. (C) 1997 Elsevier Science B.V.