DETERMINATION OF NICKEL IN SERUM OF HEMODIALYZED PATIENTS BY MEANS OFELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY WITH DEUTERIUM BACKGROUND CORRECTION

In this paper, an improved method for the determination of Ni in serum by means of electrothermal atomic absorption spectrometry (ETAAS) wit h deuterium background correction is described. Analysis was performed after a 1 + 1 dilution of the serum samples with a solution containin g 1% v/v HNO, and 0.25% v/v Triton X-100. Aqueous Ni standard solution s were used for calibration. Sensitivity and accuracy were comparable to those reported for procedures based on Zeeman-effect background cor rected ETAAS. The characteristic mass was 14 pg and the average analyt ical recovery was 101.5 +/- 4.8% (n = 9). The analysis of Seronorm Tra ce Element Control Serum yielded a value of 3.21 +/- 0.17 mug l-1 (n = 10) as compared with the recommended concentration of 3.2 mug l-1. Fo r the Standard Reference Material Bovine Serum SRM 8419 from the Natio nal Institute of Standards and Technology, a value of 0.46 + 0.05 mug l-1 (n = 4) was determined by this method in agreement with recent fin dings of other researchers. Improved precision (5.8% within-day, 7.5% between-day) and detection limit (0.15 mug l-1) in comparison with a p reviously 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 mug l-1 [mean +/- sta ndard deviation (SD): 2.4 +/- 0.9 mug l-1)] and in eight women with no rmal renal function from 0.3 to 0.9 (mean +/- SD: 0.5 +/- 0.2 mug l-1) .