In-line mass transport measurement cell for improving quantification in sulfide mineral analysis using laser ablation inductively coupled plasma mass spectrometry

Abstract

An in-line mass transport measurement (MTM) cell was developed that facilitates quantification of the amount of debris transported to the plasma as the result of the laser ablation of a wide variety of sulfide mineral sample types. Variation in the amount of material transported to the plasma, as the result of variation in coupling and ablation efficiency of the laser, has, in the past, resulted in poor signal reproducibility and lack of analytical precision. This is particularly true when using the Nd:YAG laser at its fundamental wavelength of 1064 nm. The problem is further exacerbated by the lack of suitable reference standards, which provide ‘similar’ matrices for ablation. This has significantly impacted on analytical accuracy. These problems have slowed the acceptance and application of LA-ICP-MS as an analytical tool. The in-line MTM cell provides a means of determining the amount of material transported to the plasma during ablation. Normalization of data, to the amount of debris produced significantly improved analytical precision for a wide variety of sulfide mineral sample types and decreased the dependence on exactly matrix-matched standards. The cell has found specific application in the analysis of sulfide minerals for geochemical exploration purposes.