Determination of nickel in serum of haemodialysed patients by means of electrothermal atomic absorption spectrometry with deuterium background correction

Abstract

In this paper, an improved method for the determination of Ni in serum by means of electrothermal atomic absorption spectrometry (ETAAS) with deuterium background correction is described. Analysis was performed after a 1 + 1 dilution of the serum samples with a solution containing 1% v/v HNO₃ and 0.25% v/v Triton X-100. Aqueous Ni standard solutions were used for calibration. Sensitivity and accuracy were comparable to those reported for procedures based on Zeeman-effect background corrected ETAAS. The characteristic mass was 14 pg and the average analytical recovery was 101.5 ± 4.8%(n= 9). The analysis of Seronorm Trace Element Control Serum yielded a value of 3.21 ± 0.17 µg l^–1(n= 10) as compared with the recommended concentration of 3.2 µg l^–1. For the Standard Reference Material Bovine Serum SRM 8419 from the National Institute of Standards and Technology, a value of 0.46 ± 0.05 µg l^–1(n= 4) was determined by this method in agreement with recent findings of other researchers. Improved precision (5.8% within-day, 7.5% between-day) and detection limit (0.15 µg l^–1) in comparison with a previously reported procedure based on ETAAS with deuterium background correction was obtained. Serum Ni levels determined by this method in 25 haemodialysed patients ranged from 0.7 to 4.0 µg l^–1[mean ± standard deviation (SD): 2.4 ± 0.9 µg l^–1] and in eight women with normal renal function from 0.3 to 0.9 (mean ± SD: 0.5 ± 0.2 µg l^–1).