Application of a Dual-Mode Detection System for ICP-MS. Part I: Determination of Majors, Minors, and Traces in Geostandards

Abstract

The high-gain pulse-counting detection systems currently used in ICP-MS, although exhibiting excellent characteristics for trace analysis, have only a finite gain. At count rates of the order of 106 cps, gain suppression occurs, thus effectively limiting the upper measurable concentration ranges to a few μg mL−1. It is possible to utilize such detections in an analogue mode, whereby the output signal is a direct function of the applied voltage. In this paper, the applicability of a detection system employing both analogue and pulse-counting detection is evaluated, with particular emphasis on the determination of majors, minors, and traces in geological reference materials. In addition, two sample preparation modes are compared; in the first, a conventional lithium metaborate fusion is utilized, while alternatively, a rapid slurry technique is found to be particularly effective for some more volatile elements.