Whole blood analysis by ICP-MS and ICP-OES with the preconcentration of heavy and rare earth metals on graphene oxide

Abstract

The determination of heavy metals and rare earth elements (REEs) in environmental and biological objects is important for biomonitoring. The composition of whole blood provides information about the general condition of the body and its environment. The limits of detection (LODs) of analytes provided by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES), in some cases, are insufficient to detect trace amounts of analytes. In this work, a new method for human whole blood analysis is proposed. Graphene oxide (GO) obtained by microwave exfoliation of graphite oxide was used for the preconcentration of analytes from human whole blood samples. This method allows for a significant reduction in matrix effects and the sampling dilution factor. Sorption preconcentration allows to improve LODs of analytes by an average 13 times compared to sample preparation procedures with acid digestion. The LODs of the analytes from 3 to 1000 ng L⁻¹ for ICP-MS and from 100 to 10 000 ng L⁻¹ were obtained for ICP-OES analysis with preconcentration. The developed method allows for the quantitative determination of 25 analytes (Be, Cr, Cu, Hf, In, Pb, Sn, Ti, Zr and REEs). The analyte recoveries ranged from 75% to 114%. The use of GO for sorption preconcentration of analytes provides a significant improvement in the LODs of analytes and allows for obtaining a more detailed information on the composition of whole blood during ICP-MS and ICP-OES analyses.