Evaluation of pneumatic nebulization and ns-laser ablation ICP-MS for bulk elemental analysis and 2-dimensional element mapping of iron meteorites

Abstract

The capabilities and limitations of nanosecond laser ablation ICP-mass spectrometry for bulk and spatially resolved (elemental mapping) analysis of iron meteorites were assessed. The quantitative data obtained were compared to those obtained i. via multi-element solution ICP-MS (after digestion) relying on external calibration and, ii. high-accuracy determination of selected platinum group elements using solution ICP-MS after target element isolation using anion exchange chromatography and deploying isotope dilution. Results generated by the different methods described show good agreement. Significant matrix effects were observed to affect the results of the ns-LA-ICP-MS analysis of iron meteorites, making quantification via a matrix-matched standard a prerequisite. Careless use of intensity distribution maps without proper correction for laser-solid coupling efficiency can lead to incorrect interpretation of the element maps. ns-LA-ICP-MS was shown to be suitable for fast and quasi-nondestructive analysis of iron meteorites, not only homogeneous ataxites and hexahedrites, but also more heterogeneous ones, when considering ablated areas of a sufficient size. In the context of elemental mapping using LA-ICP-MS, Pearson's product–moment correlation analysis was demonstrated to be a powerful tool that can provide valuable information on the fractionation of the elements in the parent bodies of meteorites.