New horizons in human biomonitoring of environmentally and occupationally relevant metals-sector-field ICP-MS versus electrothermal AAS

Sector-field ICP-MS (SF-ICP-MS) was used for the quasi-simultaneous determination of selected trace and ultra-trace elements of occupational and environmental interest, such as Al, Co, Cr, Cu, Fe, Mn, Ni, Pt, V and Zn, in human urine and serum. In the case of urine, Pb, Cd and Tl were additionally determined. Sample pretreatment was restricted to UV photolysis and to a subsequent moderate dilution with 0.5% HNO3 solution without using any chemical separation and enrichment. Contamination was carefully controlled at each step of the analytical procedure. Calibration was carried out by the standard addition procedure. Owing to spectral interferences, the determination of Al, Co, Cr, Cu, Fe, Ni, V and Zn was performed in the medium resolution (MR) mode (m/Delta m congruent to 3000), while the determination of non-interfered elements, such as Cd, Mn, Pb, Pt and Tl, was carried out at low resolution (LR) to gain a maximum of sensitivity. The accuracy of the procedure was checked by the analysis of commercially available quality control serum and urine samples, by comparison with electrothermal (ET-)AAS as a second independent method and by successful participation in an inter-laboratory comparison programme. The results obtained with both methods were in excellent agreement. Regarding the quality control materials, good agreement was also achieved between the found and assigned values. The described SF-ICP-MS multi-element method is thus suitable for the quasi-simultaneous determination of trace and ultra-trace elements in urine and serum covering a wide range of concentrations. It is especially valuable for rapid multi-element screening purposes in cases of unknown exposures (non-target screening) and for determinations at very low concentrations, which are not accessible to AAS techniques.