Comparison of LA-ICP-MS and LA-ICP-OES for the analysis of some elements in fly ashes

In this work quantitative analysis of minor and trace elements in fly ash by nanosecond laser ablation (LA)-ICP-MS and LA-ICP-OES was investigated in terms of detection limits and accuracy. Different binders and modifiers (silver or chromophores) were added to the fly ash powder to prepare mechanically stable pellets and improve sensitivity (signal to concentration ratio). Maleic acid was found to provide a higher degree of homogeneity between sensitivities across the different fly ashes tested. Ashes were from different origins: domestic waste incinerator or ashes from various coal-fired power plants. A calibration procedure using reference materials as standards was employed, the LAI-CP-MS analysis gave an acceptable accuracy (estimated from NIST 1633), better results were obtained using fused bead preparation. The use of the LA-ICP-OES system gave, when possible (higher concentrations), good results in terms of detection limits (1 to 11 mu g g(-1)) and accuracy.