Study of arsenic-protein binding in serum of patients on continuous ambulatory peritoneal dialysis.

Arsenic (As) bound to serum proteins in patients on continuous ambulatory peritoneal dialysis (CAPD) was studied. A prior experiment by ultrafiltration showed that 5.57% of total As was bound to serum proteins for 14 CAPD patients. Further identification of the As species and protein molecules in serum of three CAPD patients with high As concentrations was carried out by combining the separation methods of size-exclusion, anion-exchange, and affinity fast-protein liquid chromatography, detected by hydride generation atomic absorption spectrometry. The results indicated that only inorganic As species are bound to serum proteins. Transferrin is the main carrier. The concentrations of As bound to proteins in serum for the three patients were 0.44 +/- 0.12, 0.19 +/- 0.09, and 0.59 +/- 0.09 microg/L (n = 3), respectively.