Capabilities and limitations of Se isotopic analysis using hydride generation coupled to MC-ICP-MS
Abou-Zeid, L.; Wiech, M.; Vanhaecke, F. (2025). Capabilities and limitations of Se isotopic analysis using hydride generation coupled to MC-ICP-MS. J. Anal. At. Spectrom. 40(8): 1964-1976. https://dx.doi.org/10.1039/d5ja00196j
In: Journal of Analytical Atomic Spectrometry. Royal Society of Chemistry: London. ISSN 0267-9477; e-ISSN 1364-5544, more
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| Author keywords |
mass-spectrometry;selenium isotopes;ratios;samples;record |
| Authors | | Top |
- Abou-Zeid, L.
- Wiech, M.
- Vanhaecke, F., more
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| Abstract |
This study presents a comprehensive methodological investigation aimed at optimizing selenium (Se) isotopic analysis using MC-ICP-MS. Fundamental aspects of the plasma were revisited through spatial profiling, enabling detailed characterization of the distribution of Se+ and ArAr+/ArArH+ species within the plasma. Increasing the sampling depth (sampling further upstream in the plasma) proved more effective than the commonly employed methane addition, offering a more effective suppression of the Ar-based species, although at the cost of some loss in the sensitivity for Se. Under these conditions, precision values (expressed as 2SD) of 0.03 parts per thousand and 0.17 parts per thousand were obtained for delta 82/78Se and of 0.08 parts per thousand and 0.38 parts per thousand for delta 82/76Se, at 100 and 25 mu g L-1, respectively. Moreover, the method proved robust, with a long-term reproducibility of 0.07 parts per thousand (2SD, n = 120) and high accuracy, even at up to 30% sample-standard concentration mismatch. However, the method's relatively high hydride formation rate (similar to 7 x 10-3) limits its applicability to samples with As/Se post-isolation ratios <= 0.05, beyond which mathematical corrections lead to biased results. Finally, the method was validated using the SELM-1 reference material, for which the delta 82/78Se and delta 82/76Se values were in excellent agreement with published data, and was subsequently applied to a set of tuna fish organs (liver, spleen, kidney, and intestine). This study demonstrates that the method that was developed, optimized and validated forms a solid basis for further investigating Se metabolic pathways in marine fish and for elucidating its role in Hg detoxification. |
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