THE DETERMINATION OF SILVER IN WHOLE-BLOOD AND ITS APPLICATION TO BIOLOGICAL MONITORING OF OCCUPATIONALLY EXPOSED GROUPS

A sensitive and rapid technique for directly measuring silver in blood , using electrothermal atomization atomic absorption spectrophotometry (ETAAS) is described. The method can be used to analyse precisely up to 40 blood samples a day in duplicate. Well-mixed, whole blood sample s, collected in EDTA, were diluted 1+4 with a diluent containing 40 g l.(-1) ammonium dihydrogen orthophosphate and 0.5 ml l.(-1) Triton X-1 00. Aliquots of diluted blood were then analysed by ETAAS using wall a tomization with a pyrolytically coated tube. The coefficient of variat ion for within-run precision was 4.55% at 10 mu g l.(-1) and 5% at 25 mu g l.(-1) Between-run variation, it was 4.1% at 25 mu g l.(-1) The a nalytical recovery for the method was 98% +/-3% at both 8 and 30 mu g l.(-1) The detection limit of the method was 0.1 mu g l.(-1), which wa s sufficiently sensitive to distinguish exposed from non-exposed indiv iduals. Blood silver levels in unexposed subjects were found to be bet ween <0.1 and 0.2 mu g l.(-1). Blood silver levels were determined in 98 occupationally exposed workers involved in bullion production, cutl ery manufacture, chemical manufacture, jewellery production and silver reclamation. Blood silver levels ranged from 0.1 to 23 mu g l.(-1), w ith some of the highest levels found in silver reclaimers. (C) 1996 Pu blished by Elsevier Science Ltd for BOHS.