2.5.3. ICP-OES

A ratio of 3:1 *v*/*v* HCl to HNO3 was used to digest a representative sample of the final product obtained at the end of each experiment and resulting solutions were analyzed by ICP-OES to determine the elemental content of the sample (Thermo Electron Duo View iCAP 6500, Waltham, MA, USA).
