Simultaneous analysis of 21 elements in foodstuffs by ICP-MS after closed-vessel microwave digestion: Method validation

This paper describes a validation process for the simultaneous analysis of 21 elements: lithium (Li), aluminium (Al), vanadium (V), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), arsenic (As), strontium (Sr), molybdenum (Mo), silver (Ag), cadmium (Cd), tin (Sn), antimony (Sb), tellurium (Te), barium (Ba), mercury (Hg) and lead (Pb) in food samples by inductively coupled plasma-mass spectrometry (ICP-MS) after closed-vessel microwave digestion. This validation was realized in parallel with the analysis of the 1322 food samples of the second French Total Diet Study (TDS) by the National Reference Laboratory (NRL) of the French Food Safety Agency (AFSSA). Several criteria such as linearity, limits of quantification (LOQ), specificity, precision under repeatability conditions and intermediate precision reproducibility were evaluated. Furthermore, the method was supervised by several internal and external quality controls (IQC and EQC). Results indicate that this method could be used in the laboratory for the routine determination of these 21 essential and non-essential elements in foodstuffs with acceptable analytical performance.