A feasible method for determining catalysts residues in margarine by ICP-MS

Margarine consumption has increased significantly over the last few decades. However, there has been a lack of green, secure and efficient methods in the literature that would allow for the determination of catalyst waste (such as Ni, Pd and Pt) in these products with suitable precision and accuracy. These catalysts are commonly employed in industrial processes and, when not efficiently removed, may be deleterious to human health. Inductively coupled plasma mass spectrometry (ICP-MS) is one of the most suitable techniques for this purpose in view of its high sensitivity, multielemental capability and wide linear dynamic range. On the other hand, elemental determination by ICP-MS generally requires previous sample preparation, and the final solution should be free of species that can cause problems in this step. In this way, the microwave-assisted ultraviolet digestion (MW-UV) is a promising sample preparation method and, considering its characteristics, such as high digestion efficiency, it can provides suitable solutions for ICP-MS analysis. However, it has never been applied for digestion of samples with high fat content, such as margarine. Thus, in this work, the MW-UV method was evaluated for sample preparation of margarine to determine catalyst waste by ICP-MS.