A new demountable hydrofluoric acid resistant triple mode sample introduction system for ICP-AES and ICP-MS

摘要

A new sample introduction system with a triple mode function was developed by modifying a commercially available cyclonic spray chamber and combining it with a commercial parallel path nebulizer. The system can be used for nebulization only, vapor generation (hydride or cold vapor) only and both together (dual mode). The introduction system is very practical in use, as it can be dismantled from the bottom side and all the inserts can be removed and cleaned easily after the end of analysis. Unlike another commercial multimode system, this new one is HF-resistant and can be used with all acids. The analytical performance of the new HF-resistant triple mode sample introduction system (HFR-TMSIS) was studied by coupling it with ICP-AES and ICP-MS and comparing the performance with the conventional single mode HF-resistant sample introduction systems: i.e. a V-groove nebulizer with Sturman-Masters spray chamber for ICP-AES and cross flow nebulizer with double pass spray chamber for ICP-MS. The performance of the new system was studied using the various modes, determining As, Cd, Cu, Fe, Mn and Pb using ICP-AES and Cd, Cu, Hg and Pb using ICP-MS. In the first case NaBH_4 was used for hydride generation (of As), and in the second case SnCl_2 was used for generation of cold vapor (Hg). For both ICP-AES and ICP-MS, the use of HFR-TMSIS improved the analytical performance of both As and Hg in hydride and cold vapor generation mode, respectively, and also in the dual mode compared to the conventional single mode systems. For the other elements the figure of merits of nebulization and dual mode were comparable with the conventional systems. Cold vapor generation mode (for the determination of Hg) and dual mode (for simultaneous determination of cold vapor of Hg together with other elements) were used for the analysis of various CRMs (digested with HF + HNO_3 + H_2O_2 or HNO_3 + H_2O_2) by ICP-MS.