Direct multielement determination of human hair by induction-heating electrothermal vaporization with ICP-MS

Abstract

Conventional methods of hair analysis using instruments, such as inductively coupled plasma-mass spectrometry (ICP-MS), typically require a digestion step that has many disadvantages. As an alternative, we report on the application of an induction heating-electrothermal vaporizer (IH-ETV) with ICP-MS detection for direct multielement determination of sub-milligram amounts of solid hair material. As, Cd, Cu, Hg, Pb and Zn were determined using powdered hair standard reference materials (SRMs) with IH-ETV-ICP-MS. Transient profiles reveal that powdered hair SRMs and hair strands have the same analyte signal shapes, while solutions have different shapes. External standards calibration using SRMs gives results that agree with the certified values, with the precision of determination ranging from 9–54%. Absolute detection limits ranged from 0.01–8 ng. These values are sufficiently low that they should allow the determination of metals at natural levels in a single human hair strand.