Hydride generation graphite furnace atomic absorption determination of bismuth in clinical samples with in situ preconcentration

A sensitive method for the determination of bismuth in clinical samples using hydride generation/ trapping and atomization in a graphite furnace is described. Addition of Pd-Lr to the furnace tube surface before hydride trapping leads to great improvement in the sensitivity of the method. Calibration is achieved with simple aqueous standards carried through this same procedure. An absolute detection limit (3 sigma) of 100 pg and a concentration detection limit of 20 ng/liter are obtained using 5-ml sample volumes. Corresponding precisions of 8-12% are typical for analyses of these samples. Microwave-assisted sample digestion procedures using HNO3 and H2O2 were used to decompose clinical materials. The method was used to determine Bi in human blood, serum, urine, and tissue before and after intake of therapeutic doses of colloidal bismuth citrate. (C) 1995 Academic Press, Inc.