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An evaluation of M2+ interference correction approaches associated with As and Se in ICP-MS using a multi-day dataset along with ICP-MS/MS/HR-ICP-MS based analysis and hierarchical modeling as a means of assessing bias in fortified drinking waters and single component matrices
Citation:
Smith, S., R. Martin, N. Hanks, P. Creed, K. Kovalcik, R. Wilson, K. Kubachka, J. Brisbin, J. Landero Figueroa, AND John Creed. An evaluation of M2+ interference correction approaches associated with As and Se in ICP-MS using a multi-day dataset along with ICP-MS/MS/HR-ICP-MS based analysis and hierarchical modeling as a means of assessing bias in fortified drinking waters and single component matrices. JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY. Royal Society of Chemistry, Cambridge, Uk, 37(4):898-909, (2022). https://doi.org/10.1039/D1JA00407G
Impact/Purpose:
The journal article looks at various M2+ correction approaches and were evaluated with the overall goal of finding M2+ correction approaches that perform well in a variety of sample matrices, over multiple analysis days, and are applicable to different instrument tunes. Most of these approaches utilize an internal standard to track the M2+ correction factors drift during an analysis batch. The authors see the use of internal standards to track M2+ correction as novel within the ICP-MS literature, while accepting that good correlations across sample type, analysis day and instrument tune likely only generate a robust correction approach for instruments with similar sampling interfaces, ion optic, and collision cell designs.
Description:
Three ½ mass oriented REE M2+ correction approaches (fixed factor, a dual internal standard, and an in-sample) are evaluated for use in an ICP-MS environment method update. The multi-variant-based evaluation includes analyzing the same 19 REE-fortified matrices on eight different days over a two-month period using two instrument tunes. These REE-fortified matrices were also analyzed using HR-ICP-MS and ICP-QQQ to estimate the true value for use in the PCA and hierarchical modeling evaluation. A fixed factor is unable to compensate for matrix and mass dependent drift and because of this generated the largest across matrix, tune, and day 95th percent confidence bounds for the REE corrections on both As (1.1ppb) and Se (23ppb) using samples fortified with 100ppb Nd, Sm & Gd. The PCA analysis indicated that M2+ ions cluster together across matrix, tune and day better than M1+ and these tighter correlations are reflected in reduced 95th percentile confidence bounds for dual M2+ internal standards (M2+; As = 0.3ppb; Se = 5.4ppb; n=704) relative to M1+ internal standards (M1+; As = 0.6ppb; Se = 12.0ppb; n=1056). The use of an in-sample M2+ correction produced comparable 95th percent confidence bounds (As = 0.2ppb; Se = 3.4ppb; n=352) relative to the M2+ internal standard approaches. Finally, the hierarchical modeling indicated M2+ ions as internal standards tend to minimize the across day variability induced by cone changes and the daily reoccurring matrix shifts in the M2+/M1+ ratio associated with 250ppm matrices of Na, Ca, and Mg.
URLs/Downloads:
DOI: An evaluation of M2+ interference correction approaches associated with As and Se in ICP-MS using a multi-day dataset along with ICP-MS/MS/HR-ICP-MS based analysis and hierarchical modeling as a means of assessing bias in fortified drinking waters and single component matrices
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