Clumped Isotope Analysis of Calcite and Dolomite Mixtures Using Selective Acid Extraction

作     者：Sen Li Andrew Schauer Alexis Licht Jie Liang Kate Huntington Kangning Peng Sen Li;Andrew Schauer;Alexis Licht;Jie Liang;Kate Huntington;Kangning Peng

作者机构：Qingdao Institute of Marine GeologyQingdao 266237China Department of Earth and Space SciencesUniversity of WashingtonSeattle 98195USA Centre Européen de Recherche etd􀆳Enseignement des Géosciences del􀆳Environnement(Cerege)UMR 7330Aix-Marseille UniversitéCNRSIRDINRAEAix-en-Provence 13545France Shandong Provincial Territorial Spatial Ecological Restoration CenterJinan 250014China 

出 版 物：《Journal of Earth Science》 (地球科学学刊（英文版）)

年 卷 期：2023年第34卷第3期

页      面：726-734页

核心收录：

学科分类：070902[理学-地球化学] 0709[理学-地质学] 07[理学] 0708[理学-地球物理学] 

基　　金：funded by the fellowship of the China Postdoctoral Science Foundation(No.2020M682134) the National Natural Science Foundation of China(Nos.41872149,42076220) the Shandong Postdoctoral Innovation Research Project。 

主　　题：mixed carbonate samples selective acid extraction acid fractionation correction clumped isotope bulk isotope calcite dolomite 

摘      要：Acid extraction methods have been used in the last half century to selectively extract the CO_(2)produced from different carbonate minerals in mixed samples.However,these methods are often time-consuming and labor intensive.Their application to clumped isotope(Δ47)analysis has not been demonstrated.We propose here an acid extraction method with phosphoric acid for bulk stable and clumped isotope analysis that treats mixtures of calcite and dolomite the same regardless of the proportional composition.CO_(2)evolved from calcite is extracted by allowing a reaction with phosphoric acid to proceed for 10 min at 50℃.We then extract CO_(2)evolved from dolomite by rapid ramping the acid temperature from 50 to 90℃and allowing the reaction to complete.The experimental results show that our method yields accurate calcite and dolomiteΔ_(47)values from mixed samples under different proportional compositions.Our method also displays equal or higher accuracy for calciteδ^(13)C and dolomiteδ^(13)C andδ^(18)O values from mixtures when compared to previous studies.Our approach exhibits higher sample throughput than previous methods,is adequate for clumped isotopic analysis and simplifies the reaction progression from over 24 h to less than 2 h,while maintaining relatively high isotopic obtaining accuracy.It yet poorly resolves calciteδ18O values,as found with previous methods.