Adsorption on UiO-66 for preconcentration, matrix separation, slurry sampling and in situ hydride generation-atomic fluorescence spectrometric determination of trace bismuth in alloy and water

Abstract

The determination of trace bismuth in environmental or alloy samples are rather challenging due to the low abundance and interferences arising from complicated sample matrix including heavy metals. In this work, Zr-based metal organic frameworks (UiO-66) was prepared and utilized to selectively extract Bi(III) from water samples or digests of iron alloy. Following simple centrifugation separation, Bi(III)-adsorbed UiO-66 was re-suspended in dilute hydrochloric acid for direct slurry sampling and in-situ hydride generation for atomic fluorescence spectrometric (HG-AFS) detection of bismuth. Experimental conditions affecting the adsorption of Bi(III) on UiO-66 as well as the slurry sampling HG-AFS process were carefully investigated. Under the experimental conditions, a limit of detection (LOD) of 0.1 ng/mL was achieved for bismuth. Inspiringly, the method could resist interferences from transition metals like Cu(II), Ni(II) and Fe(III), and this ensured reliable analytical results for the determination of trace bismuth in high-purity iron alloy, seawater, and river water samples.