A simple method for the preparation of homogeneous and stable solid powder standards: Application to sulfide analysis by LA-ICP-MS

A simple method for immobilizing powder samples was proposed to prepare calibration standards for the analyses of bulk elemental compositions of solid samples by LA-ICP-MS. Upon mixing with epoxy resin, the multielement doped powder was transformed into a stable and mechanically resistant target. Using this method, a sulfide standard, RPSS (resin preserved silver sulfide), was developed that contains 47 different elements, including PGE, chalcophile elements, siderophile elements, lithophile elements, and REE. The homogeneity of most elements in the original sulfide powder pressed pellet and RPSS was better than 10% (RSD, one sigma) at a microscale of larger than 24 mu m. The mass fractions of most elements in the RPSS determined by LA-ICP-MS analyses, calibrated against the pressed pellet, agreed well with that of solution ICP-MS analyses. This result indicates no significant matrix effect between the RPSS target and the original powder pellet. The proposed method is convenient for quickly preparing homogenous and stable solid powder standards for LA-ICP-MS analysis. It is particularly suitable for the development of sulfide standards because it prevents them from oxidation when exposed to air; thus, the target can be preserved for long periods of time.

Automated summary

The proposed method involves mixing multielement doped powder with epoxy resin to prepare stable and mechanically resistant targets for LA-ICP-MS analysis of bulk elemental compositions of solid samples. This method allows for the development of sulfide standards with good homogeneity and prevents oxidation, enabling long-term preservation. The analysis results show no significant matrix effects between the RPSS targets and original powder pellets, confirming the accuracy and reliability of the method.