Quantitative analysis using LA-ICP-MS and powder samples dispersed in polyvinyl alcohol films

The combination of laser ablation and inductively coupled plasma mass spectrometry (LA-ICP-MS) is a powerful tool for direct analysis of solid samples. However, quantitative analyses by LA-ICP-MS require matrix-matched standard materials, which are not always available. In this study, we have developed a method that enables quantitative analyses of powder samples using LA-ICP-MS. The sample powder is dispersed in a polyvinyl alcohol (PVA) paste, which is a hydrophilic resin, and a film sample is obtained by a screen-printing technique. Analyte concentrations can be determined by a standard-addition method using an analyte-spiked film prepared by mixing standard solutions into the PVA paste. Because of its hydrophilicity, it is possible to increase the ratio of analytes (standard solutions) to the resin. Despite samples being diluted with the resin, this method has enough sensitivity to detect elements at concentrations < 0.1 μg/g. Several types of ceramic powder (SiC, ZrO₂, and TiO₂) were analyzed using this method, and all the analytes, the concentrations of which differed by five orders of magnitude (from < 1 μg/g to > 1 wt%), were accurately quantified. This method, in which reliable matrix-matched standard materials are easily tailored for each sample, can be potentially important in quantitative analyses using LA-ICP-MS.