Abstract
Laser ablation combined with quadrupole- or multiple collector-type ICP-MSs has rapidly become one of the most important tools for in situ analyses of elemental and isotopic compositions of a wide variety of geological materials. This technique features direct solid sampling at high spatial resolution, depth profiling ability, and high data throughput. Newest models of laser ablation system prefer short laser wavelength and short pulse width (e.g. femto-second laser) to minimize ablation induced elemental and isotopic fractionation. Quantitative analysis has usually been carried out by external calibration using NIST synthetic glasses (typically SRM 612 and 610) as reference standards and a naturally-occurring major element with known concentration as internal standard to correct for the ablated mass and instrumental drift. However, recent studies demonstrate that this calibration is affected by matrix effects. Calibration against NIST glasses may cause significant inherent bias because of large difference in major compositions between the NIST glasses and most of geological samples. Using a 193 nm argon fluoride (ArF) excimer laser ablation system, we investigated the validation of NIST SRM 612 and USGS glasses (BHVO-2G and BCR-2G) as calibration standards for determination of incompatible trace elements in MPI-DING reference glasses (Jochum et al 2005) and mineral separates of mantle xenoliths.
