Determination of Se and Te in coal at ultra-trace levels by ICP-MS after microwave-induced combustion

• Published in: Journal of analytical atomic spectrometry 2019-05, Vol.34 (5), p.998-14
• Main Authors: Rondan, Filipe S, Henn, Alessandra S, Mello, Paola A, Perez, Magali, Bullock, Liam A, Parnell, John, Feldmann, Joerg, Flores, Erico M. M, Mesko, Marcia F
• Format: Article
• Language: English
• Subjects: Coal; Combustion; Emission spectroscopy; Feasibility studies; Inductively coupled plasma mass spectrometry; Inorganic acids; Mass spectrometry; Scientific imaging; Tellurium; Vaporization
• ISSN: 0267-9477; 1364-5544
• DOI: 10.1039/c9ja00048h

A method for ultra-trace determination of Se and Te in coal by inductively coupled plasma mass spectrometry (ICP-MS) was developed. Samples (up to 500 mg) were prepared by microwave-induced combustion (MIC) in a closed system pressurized with 20 bar of oxygen. Inorganic acids or their mixtures were evaluated as absorbing solution. Using HNO 3 + HCl (1 + 1), results obtained for Se and Te after sample preparation by MIC agreed with those obtained by reference methods, microwave-assisted wet digestion (MAWD) using concentrated HNO 3 and HF, and solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry (SS-ETV-ICP-MS), and also with a certified reference material of coal (NIST 1632c) for Se. Very low limits of quantification (LOQ) were obtained: 0.002 and 0.007 mg kg −1 for Se and Te, respectively. Major elements were determined in final solutions obtained by MAWD and MIC, and their concentration in solutions of MIC was negligible (