Comparison of sampling modes for inductively coupled plasma mass spectrometry determination of Se and Te in geological samples

This study focuses on comparing the performance of pneumatic nebulization (PN), hydride generation (HG), and photochemical vapor generation (PVG) sampling modes coupled with inductively coupled plasma mass spectrometry (ICP-MS) for the determination of Se and Te in geological samples. ICP-MS operating parameters for each sampling mode, such as the RF power, flow rate of collision gas, and sampling depth, were optimized. The introduction efficiency of Se and Te in PN mode was about 4.71% and 4.58% respectively, with the best reproducibility. HG mode had the highest introduction efficiency (57.01% for Se and 53.02% for Te), but the poorest reproducibility. PVG mode showed a good balance between efficiency and reproducibility, with introduction efficiencies of 45.38% for Se and 38.84% for Te, and lower limits of detection (LODs) of 0.001 μg L^-1 for both Se and Te. Analysis of 14 geological certified reference materials (CRMs) indicated that for samples with Se > 0.1 μg g^-1 and Te > 0.05 μg g^-1, both PN and PVG sampling modes can obtain satisfactory results, and PN mode is more convenient. For samples with Se ≤ 0.1 μg g^-1 and Te ≤ 0.05 μg g^-1, HG or PVG sampling modes are recommended after enrichment pretreatment. This research provides a more precise and reliable method selection basis for analyzing Se and Te in geological samples at different concentration levels.