[Determination of bismuth pectin by flow-injection hydride-generation atomic absorption spectrometry]

A new method was developed by flow-injection hydride-generation atomic absorption spectrometry (FI-HG-AAS) for direct determination of bismuth in bismuth pectin, which is mostly composed of pectin and bismuth and serves as one of pharmaceuticals for protecting stomach mucous membrane. The influences of some experimental parameters of this method, such as the acidity of sample solution, the reductant of KBH4 and NaOH that served as the stabilizer of KBH4, were studied and these parameters were optimized. Bismuth was detected directly with the linear range of 0.00-44.00 ng.mL-1. The equation of working curve was A = 0.012 + 0.017c (c:ng.mL-1), r = 0.9995, the detection limit was 0.095 ng.mL-1 (3 sigma), and the recovery was 97.3%-103.3%. The method proposed has been used in the analysis of practical sample for bismuth with 96.6%-100.1% founded and 2.1% of RSD. Experiments showed that this method was simple, rapid, accurate and suitable for the assay of bismuth in bismuth pectin.