Evaluation of different liquid chromatography-electrospray mass spectrometry systems for the analysis of heterocyclic amines

Three liquid chromatography-electrospray ionisation (LC-ESI) MS systems are evaluated for the analysis of heterocyclic amines (HAs). The electrospray sources and analysers (ion trap, single quadrupole and triple quadrupole) have been compared in terms of performance and quality parameters. In all cases, a C8 reversed-phase column and (acetic acid-ammonium acetate 30 mM pH 4.5)-acetonitrile (ACN) as mobile phase were used. Ionisation source parameters, post-column addition and working conditions for each acquisition mode (full scan, product ion scan, selected ion monitoring, and multiple reaction monitoring) were optimised for each instrument. The MS-MS spectra obtained with the ion trap and the triple quadrupole systems were very similar in both fragment ions and relative abundances, except for carbolines that showed adduct formation in the ion trap. Quality parameters were established and good precision (relative standard deviations (R.S.D.) < 12%) and very low limits of detection were obtained, mainly when using the triple quadrupole (< 9 pg injected). The content of HAs in a lyophilised beef extract was determined using the three instruments in order to compare their applicability for routine HAs analysis.