Optimization of Sample Preparation in the Determination of Minerals and Trace Elements in Honey by ICP-MS

In this paper, analytical procedures are proposed for determination of inorganic constituents in honey samples from different regions of Brazil. Inductively coupled plasma with mass spectrometry detection (ICP-MS) was used to determine the analytes, using two different sample preparation methods: acid mineralization in block digester and microwave-assisted acid digestion. The methods were optimized in order to minimize the final acidity and the residual carbon content after the sample preparation. It was observed that mineralization using microwave radiation with 2 mol L-1 HNO3 was the most suitable method for determination of minerals and trace elements by ICP-MS. Besides, Se, Mg, Ca, Al, P, Mn, Fe, Cu, Zn, Ba, and Pb were determined in 60 honey samples by ICP-MS. The appropriate instrumental conditions were also evaluated for this determination, as the need of the use of collision-reaction interface and internal standards. The accuracies were evaluated using two certified reference materials, and the recoveries ranged from 82 to 115 %. The results showed no evidence of contamination in the honey samples analyzed.