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.
With increasing use of bismuth in industry, a better understanding of its environmental behaviour is required, including an improved knowledge of its background concentration range in (non-saline) freshwaters. However, the poor analytical sensitivity of previous methods may lead to inaccurate measurement results for Bi 3+ in environmental samples. In this work, cobalt ion-assisted photochemical vapour generation (PVG) was developed for the detection of trace Bi with inductively coupled plasma-mass spectrometry (ICP-MS) measurement. The volatile species of Bi was found to be (CH 3 ) 3 Bi generated under UV irradiation in the presence of formic acid, acetic acid and Co 2+ . The major parameters potentially influencing the detection of Bi were investigated. Under optimised conditions, the limit of detection (3 s , n = 11) of the proposed method was 0.3 ng l −1 . The analytical sensitivity was enhanced about 70-fold for Bi 3+ compared with that using classic pneumatic nebulisation of ICP-MS. Furthermore, the proposed method showed better analytical sensitivity and anti-interference ability towards co-existing ions compared with ferric ion-assisted PVG systems. The accuracy of the proposed method was evaluated by analysis of environmental water samples and certified reference materials with satisfactory results.
As the impurities in alloy may affect its mechanical and physical properties, the determination of trace elements is important to ensure the quality of alloy. However, accurate determination of trace impurities in alloy samples is a big challenge due to their complicated matrix and low concentrations. In this work, matrix-assisted photochemical vapor generation (PVG) was developed for the determination of impurity in alloy samples by inductively coupled plasma mass spectrometry (ICPMS). Bismuth was selected as the target element, which is detrimental to the strength of alloy even at very low concentration. The transition ions existed in alloy worked as the “sensitizers” for the efficient PVG of bismuth, and only formic acid and acetic acid were required for the analysis of alloy samples after digestion. This largely reduced the risks of sample contamination and analyte loss in multiple sample pretreatment involved in conventional analytical methods. The PVG efficiency of bismuth was greatly enhanced, making the sensitive and simple determination of trace analytes in alloy samples feasible. The limit of detection (LOD, 3σ) for Bi was found to be 0.4 ng L − 1 corresponding to 0.54 ng g − 1 for analysis of 0.5 g of alloy sample. A relative standard deviation (RSD) of 1.1% was obtained from seven replicate measurements of 0.5 μg L − 1 Bi 3+ in sample matrix. The proposed method was successfully applied for the determination of Bi in two certified reference materials (Fe Ni based alloys GBW01621 and GBW01622).
危险品化学品经营许可证（带存储）