CHEMICAL SPECIATION OF ARSENIC IN SERUM OF UREMIC PATIENTS

Chemical speciation of arsenic was carried out in serum of a total of 51 uraemic patients: 19 non dialysis (ND), 18 haemodialysis (HD) and 1 4 continuous ambulatory peritoneal dialysis (CAPD) patients, The low m olecular mass As species were separated by ion-exchange liquid chromat ography and measured on-line by hydride generation atomic absorption s pectrometry (HGAAS), The high molecular mass As species were separated by fast protein liquid chromatography, either size-exclusion, ion-exc hange or affinity chromatography; and the fractions were digested and measured off-line with HGAAS. The mean total As concentrations in the serum of the three groups of the uraemic patients were significantly h igher than the reference value (6.47 +/- 4.28, 5.12 +/- 5.58 and 4.67 +/- 5.41 mu g l(-1) for HD, ND and CAPD patients, respectively, versus the reference value of 0.96 +/- 1.52 mu g l(-1)), The major As specie s in serum of the patients were dimethylarsinic acid (DMA) and arsenob etaine, The HD patients showed a significantly higher mean DMA level t han ND and CAPD patients, No selective removal of different As species in serum of HD patients was observed after 4 h of haemodialysis, The inorganic As species in serum were bound to proteins, mainly transferr in (about 5-6% of total As in serum), This binding may play an importa nt role in arsenic detoxification.