Multi-element analysis of solid food materials via mixed standards pellet laser ablation inductively coupled plasma mass spectrometry

Accurate monitoring of minor and trace elements in food is of great significance for maintaining human health. Although laser ablation inductively coupled plasma mass spectrometry technique (LA-ICP-MS) is well-established for the direct analysis of solid sample, the lack of an appropriate external standard for quantitative calibration remains the main challenge. Herein, we developed a novel calibration strategy based on the mixed fine particulate food reference material pellets as the external standard to accurately measure the multi-elements in various solid food samples. Three in-house prepared pellet standards exhibited good homogeneity (RSD < 9%) and the limits of quantitation (LOQs) ranged from 0.0003 (Sr) to 0.86 & mu;g g-1 (Ca). Analytical results of the food NIST reference materials and typical food samples were in good agreement with the certified or reference values, respectively. The proposed method is a promising alternative for routine elemental bulk and/or imaging analysis in food safety laboratories.