Inductively Coupled Plasma Mass Spectrometry for Direct Multi-element Analysis of Diluted Human Blood and Serum

Abstract

A method for the inductively coupled plasma mass spectrometry (ICP-MS) multi-element analysis of diluted human blood and serum was used for the following elements: Co, Ni, Cu, Zn, Ga, Se, Rb, Mo, Rh, Pd, Cd, Sn, Sb, W, Pt, Hg, Tl and Pb. Sample pretreatment was a simple dilution (ten times for blood and five times for serum) with a solution containing 5 g l -1 of 25% ammonia, 0.5 g l -1 Triton X-100, and 0.5 g l -1 EDTA in Millipore water. In and Sc were used as internal standards. For sample introduction a flow-injection-type technique (based on time instead of volume) was used. The determinations were carried out first in a peak-jumping mode for selected masses, and then in a scanning mode. Each determination of a preparation took 75 s. The results for reference samples agreed with recommended or certified values for Co, Cu, Zn, Rb, Cd, Tl and Pb in blood, and for Rb, Mo and Cd in serum. For Ni and Hg in blood, and Cu and Zn in serum, the results agreed with one of two reference samples. The detection limits for all these elements (except for Tl) were sufficient for analysis of samples from the general population. On the other hand, the results for Se in blood, and for Co, Ni, Se, Sn and Hg in serum did not agree with recommended or certified values. No reference samples are available for Ga, Mo, Rh, Pd, Sn, Sb, W, or Pt in blood, or for Ga, Rh, Pd, W, Pt, or Pb in serum. Generally, the limits of detection for the elements in the latter group (below 0.15 µg l -1 ) are close to or above the levels present in the general population.