Application of inductively coupled plasma sector field mass spectrometry for elemental analysis of urine.

An analytical method using double focusing sector field inductively-coupled plasma mass spectrometry (sector field ICP-MS) for rapid simultaneous determination of 42 elements in urine is described. Sample preparation consisted of 20-fold dilution with 0.14 mol/l nitric acid in ultrapure water. The importance of controlling possible contamination sources at different sample preparation and analysis stages in order to achieve adequate method detection limits (DL) is emphasized. Correction for matrix effects was made using indium and lutetium as internal standards. Different approaches for accuracy assessment in urine analysis are evaluated. Additional information on trace element concentrations in a urine reference material is given. Between-batch precision was assessed from the analysis of separately prepared aliquots of the reference material and was better than 10% RSD for 32 of the elements. The robustness of the procedure was tested by analysis of about 250 samples in one analytical run lasting more than 50 hours. A statistical summary of results for 19 urine samples from non-exposed subjects is presented. For a majority of the elements tested concentrations were higher than the detection limit of the method.