Determination of Thallium Isotope Ratios in Ten Geological Reference Materials, and of Thallium Isotopic Fractionation Effects Related to Sample Digestion by Dry Ashing

• DOI: 10.1111/ggr.12599
• Publication Date: 2025-02-18T02:55:21Z
• Authors: Feiyu Dong; Zhaoyang Wang; Lu Yin; Jie Li
• Keywords: Thallium; Ashing

We report for the first time Tl isotope ratios ten geological reference materials (RMs), namely SGR‐1b (from USGS), and GBW07302, GBW07303a, GBW07401a, GBW03104, GBW07103, GBW07109, GBW07110, GBW07111 GBW07113 China). The principal matrix characteristics of these range from sediments to igneous rocks, including stream sediment, soil, shale, granite, nepheline syenite, trachyte, granodiorite rhyolite. Analytically, procedure we developed includes a sample digestion step, simplified single‐stage anion exchange separation step measurements by MC‐ICP‐MS. For compared dry ashing‐based process with an acid method under high‐pressure conditions. observed that RMs high organic content (e.g., = ~ 25%) showed very values loss on ignition (LOI) (~ 40%) during ashing. Moreover, isotopic measurement results were heavier after ashing than application bomb method. infer combustion conditions in case large amounts matter are probably cause fractionation effects (preferential evaporation 203 Tl). thus recommend step. validated our entire applying it well‐documented RMs, GSP‐2 (granodiorite), Nod‐A‐1 (Marine sediment), Nod‐P‐1 sediment) SCo‐1 (shale). Our agreement literature values.