Determination of bismuth in serum and urine by direct injection nebulization inductively coupled plasma mass spectrometry

Abstract

A sensitive method for the determination of Bi by direct injection nebulization inductively coupled plasma mass spectrometry (DIN-ICP-MS) in biological fluids is described. The detection limit for Bi is 9.7 ng 1-1 (ca. 46 pmol dm-3) with DIN compared with 17 ng 1-1 (ca. 81 pmol dm-3) with conventional pneumatic nebulization (PN). The absolute amount detectable by DIN-ICP-MS is about two orders of magnitude lower for DIN compared with PN (0.019 and 1.70 pg, respectively). Sample wash-out times were greatly reduced using DIN owing to minimization of the memory effect for Bi. Using T1 as an internal standard, good calibrations were obtained for Bi standards in 0.14 mol dm-3 nitric acid, serum and urine with comparable linearity between the matrices, and these were used for the determination of Bi in serum and urine samples from animals dosed with the antiulcer compound RBC (ranitidine bismuth citrate). This method is potentially useful in studies of the metabolism and biodistribution of Bi-containing drugs.