Separation of Inorganic Forms of Tellurium Using On-Site SPE Followed by ICP-MS or ICP-OES-The Right Solution for Water Monitoring.

Tellurium, recognized as one of the technology-critical elements, should be considered as a xenobiotic. Its application, i.a. in the growing photovoltaic industry, raises concerns about Te(IV) and Te(VI) release to the environment. As both forms differ in mobility and toxicity, Te speciation should be included in water monitoring, but problems with speciation changes occurring during sampling, transport, and sample storage require the use of on-site separation of Te forms. A simple procedure based on solid phase extraction (SPE) with the anionic exchange mechanism (SAX, involving commercially available columns), followed by their quantification with elemental techniques, has a high potential for implementation in routine analysis. The proposed SPE-ICP-MS (inductively coupled plasma mass spectrometry) method allows direct analysis of Te(VI) and Te(IV), with Te(IV) determined after elution from the column. The detection limits obtained for the 5.0 mL sample are 0.02 ng mL and 0.05 ng mL for Te(VI) and Te(IV), respectively. Hydride generation inductively coupled plasma optical emission spectrometry (HG-ICP-OES) was used to control possible changes in tellurium speciation occurring during species isolation using SPE. The simple and fast water pretreatment proposed here offers the possibility of separating Te(IV) and Te(VI) at the sampling site, and the elution of Te(IV) does not have to be conducted on-site. Application to the river water and seawater matrix proved the feasibility of incorporating Te speciation analysis into routine water analysis.