Use of zirconium oxychloride to neutralize HF in the microwave-assisted acid dissolution of ceramic glazes for their chemical analysis by ICP-OES

The use of a zirconium compound (ZrOCl2) to neutralize HF in the microwave-assisted acid dissolution of ceramic glazes for their chemical analysis was tested. Zr is a strong complexing agent for the fluorine ion and permits the determination of those elements which would form insoluble fluorides. The use of Zr implies strong spectral interferences and a high salt content; however, we found that at least 27 elements can be measured with low detection limits, and satisfactory precision and accuracy. In addition, the use of ZrOCl2 would permit the complete analysis of a ceramic glaze with a single attack when acid-resistant mineral phases are not present. For potassium determinations in acid matrix, the addition of an ionization buffer was studied in order to increase sensitivity, avoiding ionization interferences and non-linear calibration curves.