Comparative LA-ICP-IDMS determinations of trace elements in powdered samples using laser ablation systems with low and high ablation rates

Abstract

The results of laser ablation inductively coupled plasma isotope dilution mass spectrometry (LA-ICP-IDMS) with a special laser ablation system with high ablation rates (LINA-Spark-Atomiser), which was constructed for bulk analyses of solid samples, are compared with those obtained by one of the commonly used LA systems (UP213). Using different reference materials for validation it was demonstrated that the accuracy of LA-ICP-IDMS determinations of elements like Fe, Cu, Pb, and Zn by both systems is comparable in the concentration range of 10⁻²–10⁻⁶ g g⁻¹, but the LINA-Spark-Atomiser also provides accurate results in the sub-μg g⁻¹ range. IDMS enables accurate calibration of LA-ICP-MS determinations on a routine basis in contrast to results by non-matrix-matched calibration. The much higher ablation rate of the LINA-Spark-Atomiser also results in a higher sensitivity compared with the UP213 system, which differ by about two orders of magnitude, and also causes better precisions, which makes this system suitable for precise analyses of less homogeneous samples.