New Soil Reference Material Validation for Trace and Rare-Earth Elements by High-Resolution Inductively Coupled Plasma Mass Spectrometry

Inductively coupled plasma mass spectrometry (ICP-MS) has become inevitable for quantitative determination of trace and ultra-trace elements in geological samples. Inferences derived from ICP-MS data sets and other supportive evidence have revolutionized theories on geology/geodynamics. In this scenario, validation through interlaboratory studies plays an important role in assuring the quality of measurements, along with the performance and accreditation programs of the laboratory. The Geological Survey of India (GSI) initiated an interlaboratory testing program on soil and stream sediment testing in which about fifteen laboratories, including our geochemical laboratory participated. Trace and rare-earth elements (REE) determined on the reference material PKS-1 by high-resolution ICP-MS and validated with the certified values for PKS-1 provided by GSI after compilation. The fitness of acquired data for either “pure geochemistry” or “applied geochemistry” was determined based on the Z-scores. The data for most of the analytes fell within the -2 < Z < + 2 range, which included the majority of the trace and REE used in petrogenetic and provenance studies. These results help to review the analytical mismatches observed in the data, optimize necessary aspects and minimize the interference effects caused during analysis.