Recent advances in MC-ICP-MS applications in Earth and environmental sciences: Challenges and solutions

Abstract

• History, instrumentation of MC-ICP-MS and its up-to-date developments. • Introduction of various sampling methods including femtosecond laser ablation. • Role of CRMs in obtaining precise isotope ratios and elemental concentrations. • Technique with high potential for applications in Earth sciences and environment. The development of multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) in 1992 opened up new opportunities for geochemical, mineral exploration, and environmental studies. Recent developments in MC-ICP-MS and its hyphenation to techniques such as laser ablation including femtosecond laser sampling, advances in detection system and several other developments made MC-ICP-MS, one of the most versatile analytical techniques for the determination of isotopic compositions in several types of earth and environmental materials. Different studies in recent times indicated that MC-ICP-MS can routinely produce isotopic data that is similar in precision to those obtainable by secondary ion mass spectrometry (SIMS), sensitive high resolution ion microprobe (SHRIMP), and thermal ionization mass spectrometry (TIMS), with striking advantages such as relatively higher throughputs, ease of analysis as the source operates at atmospheric pressure, and possibility of sample introduction by other means such as laser ablation and chromatographic techniques. Recent studies demonstrate the decisive benefits of MC-ICP-MS analysis (both solution and laser ablation modes) not only isotopic ratio determinations, but also absolute element concentration determinations of several elements in the periodic table in different types of geological and environmental materials in terms of versatility, accuracy, precision and for improved spatial resolution. Laser ablation split stream (LASS) technique with ability to do dating, and capability to obtain isotopic and elemental information simultaneously in rocks and minerals on a single sampling event, when coupled to a second ICP-MS system (typically a quadrupole ICP-MS or a high resolution-ICP-MS) demonstrated its potential to become an important analytical tool in solving important problems, especially in geochemistry. The performance characteristics of MC-ICP-MS are compared with those of other similar analytical techniques such as TIMS, SHRIMP, and SIMS with recent examples. This review contains detailed descriptions of the development of MC-ICP-MS instrumentation, analytical procedures, reference materials, and focused applications in the area of geochemistry, mineral exploration, and environmental areas.