[Determination of bismuth and bismuth telluride in workplace air by ultra microwave digestion with inductively coupled plasma optical emission spectrometry].

Objective: To establish an ultra microwave digestion-inductively coupled plasma optical emission spectrometry (ICP-OES) method for the determination of bismuth and bismuth telluride in workplace air. Methods: In November 2024, workplace air samples were collected with mixed cellulose ester filters. After ultra microwave digestion at 130 ℃ for 10 minutes, ICP-OES was used to simultaneously determine bismuth and tellurium. The content of bismuth telluride was calculated by converting bismuth or telluride based on the on-site investigation. The performance indicators such as detection limit and quantitative limit of the method were analyzed. Results: The linear range of ICP-OES for determining bismuth and tellurium was 0.04-30 mg/L, and the correlation coefficients were all greater than 0.9990. The detection limit of bismuth was 0.005 mg/L. Based on the sampling volume of 75 L and the dilution volume of 50 ml, the minimum detectable concentration of bismuth telluride was 0.006 mg/m(3) and the minimum quantitative concentration was 0.020 mg/m(3). The detection limit of tellurium was 0.006 mg/L. The minimum detectable concentration of bismuth telluride was 0.008 mg/m(3) and the minimum quantitative concentration was 0.028 mg/m(3). The digestion efficiency of bismuth was 99.1%-100.0%, the intra-batch precision was 0.42%-0.51%, and the inter-batch precision was 0.50%-0.82%. The digestion efficiency of tellurium was 101.2%-103.3%, the intra-batch precision was 0.53%-0.80%, and the inter-batch precision was 0.57%-0.92%. Bismuth and tellurium were stable at room temperature within 7 days. The interference elements (silver, aluminum, arsenic, etc.) at 5 mg/L and 10 mg/L did not affect the detection of bismuth and tellurium. In the determination of simulated bismuth telluride samples, the relative deviation of bismuth was -3.8% to 4.9% and the relative deviation of tellurium was -2.1% to 6.5%. Conclusion: The ICP-OES method is simple, efficient, environmentally friendly, with high digestion efficiency and good precision. It has good selectivity and anti-interference ability and is suitable for the determination of bismuth and bismuth telluride in workplace air under various conditions.