Particle-packed column versus silica-based monolithic column for liquid chromatography-electrospray-linear ion trap-tandem mass spectrometry multiallergen trace analysis in foods

摘要

A bicarbonate buffer-based extraction method for the simultaneous analysis of five nut allergens (Ana o 2, cashew-nut; Cor a 9, hazelnut; Pru 1, almond; Ara h3/4, peanut; Jug r 4, walnut) in cereals and biscuits using liquid chromatography-electrospray-linear ion trap-tandem mass spectrometry (LC-ESI-LIT-MS~2) was developed and validated. The method was based on our earlier published LC-MS~2-based method in a research frame aimed at the identification and determination of hidden allergens in foods by using selective biomarker peptides. A C18 particle-packed column and a silica-based C18 monolithic column were compared in terms of chromatographic performances, such as peak shape, resolution, analysis time and selectivity. The C18 particle-packed column exhibited better performances and was further used for method development and validation. By operating under MS~2 selected reaction monitoring (SRM) acquisition mode, linearity, limits of detection (LOD) and quantitation, trueness and precision were evaluated on breakfast samples enriched with a mix of the five nuts. Good linearity of the matrix matched-calibration curves was obtained and detection limit values generally varied from 14 to 55mg nut/kg matrix. Recoveries were in the 76±4% to 94±3% range with RSD <15%. The capabilities of LIT to perform MS~n fragmentation was exploited to improve selectivity of the analysis, and the LC-(SRM) MS~2 method was compared in terms of LOD, linearity, precision and accuracy with a LC-(SRM) MS~3 method. Finally, both the LC-MS~2 and LC-MS~3 methods were successfully applied to the analysis of nut traces in commercially available breakfast cereals and biscuits.