Analytical capabilities of inductively coupled plasma orthogonal acceleration time-of-flight mass spectrometry (ICP-oa-TOF-MS) for multi-element analysis of food and beverages

Analytical capabilities of ICP-oa-TOF-MS for rapid, simultaneous and reliable determination of more than 50 major, trace and ultra-trace elements in different food and beverages samples (milk and dairy based products, cereals, meat, offal, sugar and sugar products, potatoes, fats, baby food samples, fruit juices, alcoholic beverages), following microwave closed vessel digestion of samples, were described. Under optimum instrumental conditions, and by using Rh as an internal standard and an external calibration method, ICP-oa-TOF-MS enables an accurate analysis, taking about one minute per a sample for all elements and isotopes of interest even for some elements such Zn, Ni, Cu, As or Co whose assay is more difficult when using conventional quadrupole instruments. In order to verify the accuracy and precision of the proposed method, 8 commercially available reference materials representing 3 major groups of food (milk and dairy based products, meat, cereals) were analysed, yielding results in agreement with certified values and the precision bellow 15%. In addition, accuracy was confirmed by spiked analytical recoveries study and accurate isotopic ratio determinations with the precision typically better than 5% with 5 s data acquisition period, also for other elements of interest whose content was not certified and different sample matrices. Limits of detection (3σ) have varied from 0.04 ng g−1 for Th to 1630 ng g−1 for Ca.