[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.