ANALYSIS OF GEOLOGICAL SAMPLES: COMPARISON OF SOLUTION ICP-MS AND FUSED GLASSES LA-ICP-MS TECHNIQUES

Abstract

The relevance of the study is caused by the need to develop new efficient sample preparation technique suitable for routine multielement ICP-MS analysis of geological samples which decreases time consumption and allows determining a wide number of elements in the range of single measurement using laser ablation (LA-ICP-MS). The main aim of the study is to compare metrological characteristics of two ICP-MS techniques, based on different sample preparation of silicate rocks – sample dissolution after melting with lithium metaborate and using prepared fused glasses for laser ablation. Objects: the international and Russian reference materials of natural rocks: basalts – BHVO-1, BHVO-2, BCR-2, granites – SG-1а, SG-3, gabbro SGD-1а, trap ST-1а. Methods: inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Results of the study showed that the developed multielement ICP-MS and LA-ICP-MS techniques allow determining a wide number of elements in geological samples in the range of single measurement using low, medium and high resolution. Internal and matrix-matched external standards for decreasing/correction of matrix effects and instrumental drift are used. Comparison of the obtained results with values of six reference geological materials verified the accuracy of the techniques. The LA-ICP-MS technique is faster due to the lack of sample preparation, but has higher uncertainty and detection limits in comparison to the ICP-MS technique.

Keywords

• inductively coupled plasma mass spectrometry (icp-ms)
• laser ablation (la)
• sample preparation
• geological reference materials
• major and trace elements
• rare earth elements