Determination of bismuth in urine by atomic absorption with hydride generation

A procedure for the determination of urinary bismuth by atomic absorption spectroscopy with hydride generation was developed and evaluated. Specimen or standard solutions were mixed with an acid mixture and an antifoam reagent. Sodium borohydride solution was then introduced to the reaction flask in order to produce bismuth hydride. The preliminary reference range for urinary bismuth was found to be less than 17 micrograms/L in 20 healthy control subjects. For patients on medications or medical treatments, bismuth levels varied from 5 to 1,460 micrograms/L. The minimum detection limit was found to be 2.5 micrograms/L and the procedure was linear to 250 micrograms/L. The intra-assay and interassay coefficients of variation at the level of 21 micrograms/L were 4.0 (N = 33) and 4.1% (N = 19), respectively. Average bismuth recovery was 97.7% for concentrations ranging from 25 to 100 micrograms/L. This procedure is simple, fast, and sensitive enough to detect levels well into the reference range. Preliminary studies also indicate this method can be used for serum bismuth determinations.