A critical look at quantitative laser-ablation ICP-MS analysis of natural and synthetic glasses

This paper examines techniques and problems of quantitative laser-ablation ICP-MS analysis for natural and synthetic glass samples and discusses internal standardization, use of calibration curves, and single-standard calibration. Internal standards are used to normalize raw intensities and are generally a low-abundance isotope of a major element in the samples. Calibration curves are necessary to define the ICP-MS response over a range of concentrations and are constructed using a series of geochemical reference standards of similar composition to the unknown materials to be analyzed. A series of calibration curves for mafic-ultramafic and felsic glasses are presented, which generally show linear behavior. However, Zr, Y, and Ce calibrations are nonlinear and exhibit higher relative intensities for these elements at higher concentrations. Calibrations using a single geochemical reference standard can be attempted only if the calibration curves are linear and pass through the origin, and if the reference standard and the samples have similar compositions.