Investigating the Influence of Non‐Spectral Matrix Effects in the Determination of Twenty‐Two Trace Elements in Rock Samples by ICP‐QMS

Abstract

The influence of non‐spectral matrix effects on the determination of twenty‐two trace elements (Rb, Sr, Y, Cs, Ba, lanthanides, Pb, Th and U) in rock samples using ICP‐MS was investigated. Three types of multi‐element solutions were synthesised containing the twenty‐two trace elements, In, Tl and ten major rock‐forming elements with varying mass fractions mimicking the compositions of basalt, peridotite and dolomite. The synthetic solutions were conditioned to have dilution factors (DF) of 1000–10000. The extent of sensitivity suppression relative to the DF = 10000 solution became more significant for smaller DF solutions, which was not constant across different elements in a single solution but displayed general dependence on m/z. This indicates that at least two internal standards (e.g., In and Tl) are required for the correction of sensitivity variation. On the basis of the results, a new isotope dilution‐internal standardisation method for the determination of twenty‐two trace elements with ICP‐MS was developed, in which the sensitivity variation was corrected by monitoring two enriched isotopes, 113In and 203Tl. This method, coupled with the quantitative correction of interference from oxides and hydroxides, achieved precise determination of twenty‐two trace elements in some rock reference materials with reproducibilities of ±2% for basaltic to andesitic samples.

A Pragmatic Approach to Coping with Matrix Effects during ICP-MS Analysis of Trace Elements in Silicate Rocks and Calibration of REE Interferences

“…Olesik and Jiao (2017) comment that with a single internal standard "recoveries were within 10% -20% for most analytes, regardless of mass". This seems to us to be an uncomfortably large fluctuation which is not simply related to mass or FIP but these values are in line with the precision quoted by Lin et al (2000) and Yokoyama et al (2016). We conclude that there is a tendency for ICP-MS data to be associated with an intrinsic, relative error of up to ±5% which it is difficult to attribute to a particular matrix-effect mechanism; this value is at the upper end of the predicted overall precision experienced for ICP-MS analyses (e.g., 2% -5%, Linge & Jarvis, 1997); 2% -4% for REE using medium resolution MS and isotope dilution standardisation (Robinson et al, 2006); an average of ±5% for 86 rock standards, Dulski (2001); and mainly ±2% -3% for isotope dilution standardisation with a few values up to ~6% -8%, Willbold et al (2003).…”

“…We conclude that the average peak suppression (matrix effect) is close to 10% and that our analytical results do not demonstrate a mass dependence for this sample at least. The count rate suppression of ~10% is similar to that reported as occurring for basalt rock digests of DF = 1000 (Yokoyama et al, 2016).…”

“…Lin et al 2000developed a "simple method" using rock digests with DF = 2000 and concluded that overcoming matrix-effects was best managed by using more dilute solutions. Yokoyama et al (2016) reported the results for key experiments carried out to quantify the optimum DF used and to assess the suitability of internal standard species, mainly using enriched isotopes and isotope dilution standardisation methods. They showed that synthetic basalt solutions having DF values > 2000 showed no decrease in sensitivity.…”

Geochemistry and Sm‐Nd chronology of a Stannern‐group eucrite, Northwest Africa 7188

“…The concentrations of major and trace elements, excluding HFSEs, were determined by the calibration curve method coupled with the internal standardization using 113 In and 113 In‐ 203 Tl, respectively (Yokoyama et al. ). We used a rock reference material, JB‐3 (basalt, Geological Survey, Japan), as the standard in the determination of major and trace elements, excluding HFSEs.…”

Magma Plumbing System at Izu-Oshima Volcano, Japan: Constraints From Petrological and Geochemical Analyses

“…The composition of the Geological Survey of Japan reference material JB-3 was measured during the course of this study; the measured and reference values (Imai et al, 1995) and the analytical errors are listed in Table 1 of Kuritani et al (2013) for the data obtained at Osaka City University and Supplementary Table S1 for the data obtained at Hokkaido University. Additional trace elements were analyzed by inductively coupled plasma mass spectrometry (ICP-MS), using a Thermo Fisher Scientific X-series II at the Graduate School of Science and Technology, Tokyo Institute of Technology, and a Thermo Fisher Scientific X-series instrument at the Graduate School of Science, Hokkaido University, using the methods described in Yokoyama et al (2016) and Lu et al (2007). The trace element concentrations for JB-3 measured during this study and its reference values are listed in Supplementary Table S1.…”