DETERMINATION OF BISMUTH IN SERUM AND URINE BY DIRECT-INJECTION NEBULIZATION INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

A sensitive method for the determination of Bi by direct injection neb ulization inductively coupled plasma mass spectrometry (DIN-ICP-MS) in biological fluids is described. The detection limit for Bi is 9.7 ng l(-1) (ca, 46 pmol dm(-3)) with DIN compared with 17 ng l(-1) (ca. 81 pmol dm(-3)) with conventional pneumatic nebulization (PN). Tbe absolu te amount detectable by DIN-ICP-MS is about two orders of magnitude lo wer for DIN compared with PN (0.019 and 1.70 pg, respectively). Sample wash-out times were greatly reduced using DIN owing to minimization o f the memory effect far Bi. Using Tl as an internal standard, good cal ibrations were obtained for Bi standards in 0.14 mol dm(-3) nitric aci d, serum and urine with comparable linearity between the matrices, and these mere used for the determination of Bi in serum and urine sample s from animals dosed with the antiulcer compound RBC (ranitidine bismu th citrate), This method is potentially useful in studies of the metab olism and biodistribution of Bi-containing drugs.