Rapid determination of Ba isotope compositions for barites using a H₂O-extraction method and MC-ICP-MS

Abstract

This study presents a rapid and simple method of high precision Ba isotope measurement for barite using H2O extraction.

High-precision double-spike Sn isotope analysis of geological materials by MC-ICP-MS

“…To correct for potential deviations from the exponential law and shi of the gains for Faraday collectors during the measurements, 42,44 a bracketing standard was used to normalize isotopic values aer a double spike inversion of each sample. 44,[72][73][74][75][76][77] Therefore, all the data are reported as the deviation of d 122/118 Sn of a sample relative to the average d 122/118 Sn of two bracketing spiked NIST 3161a, similar to Wang et al 44 The geometrical method was also used for comparison using MATLAB @ , and consistent results were found, for which the details are provided in the ESI A. †…”

Accurate determination of Ba isotope ratios in barite samples by LA-MC-ICP-MS

“…23 Tian et al established a H 2 O extraction method with a long-term reproducibility of 0.05& (d 138/134 Ba, 2SD). 24 These studies used the doublespike method to correct Ba isotope fractionation during ion exchange chromatography and instrument measurement. Because of the low solubility of barite in water or acid solution, its sample pretreatment process (e.g., chelate digestion, 25 HI acid digestion, 26 Na 2 CO 3 solution exchange, 2,10,21,27 and H 2 Oextraction method 24 ) is oen complicated and tedious.…”

“…24 These studies used the doublespike method to correct Ba isotope fractionation during ion exchange chromatography and instrument measurement. Because of the low solubility of barite in water or acid solution, its sample pretreatment process (e.g., chelate digestion, 25 HI acid digestion, 26 Na 2 CO 3 solution exchange, 2,10,21,27 and H 2 Oextraction method 24 ) is oen complicated and tedious. In addition, the spatial resolution information of the Ba isotope ratio in barite is lost when using bulk analysis methods.…”

Determining 88Sr/86Sr of barite using the Na2CO3 exchange method

“…Five methods have been applied to measure the 87 Sr/ 86 Sr of barite, which may provide useful means for 88 Sr/ 86 Sr analyses. (1) The leaching method 5,28–30 uses acid or water to leach and dissolve a small amount of barite, but the extracted Sr may not be enough for isotope measurements if the Sr content in barite is low. (2) The reduction method 31 uses HI to digest SO 4 2− based on the reaction BaSO 4 + 8HI + 2H + → Ba 2+ + 4H 2 O + H 2 S + I 2 , which produces toxic H 2 S. (3) The chelation method 20,32 is time-consuming because it takes ten days for cation exchange resins to react with barite at 90 °C.…”