Philip Staudigel , Miguel Bernecker , Allison Curley , Niels Meijer , Lkhamsuren Bayarjargal , Martin Dietzel , Jens Fiebig
{"title":"碳酸盐样品中CO2的同位素重置:对氧和团块同位素分析的影响","authors":"Philip Staudigel , Miguel Bernecker , Allison Curley , Niels Meijer , Lkhamsuren Bayarjargal , Martin Dietzel , Jens Fiebig","doi":"10.1016/j.chemgeo.2025.123012","DOIUrl":null,"url":null,"abstract":"<div><div>Exchange between CO<sub>2</sub> and water-containing phases is a consistent problem during oxygen and clumped isotope analysis of carbonate-derived CO<sub>2</sub>. Here, we have identified numerous natural and synthetic carbonates and carbonate-bearing materials that consistently reset the δ<sup>18</sup>O, ∆<sub>47</sub> and ∆<sub>48</sub> values of analyte CO<sub>2</sub> during acidification in a common acid bath and, thereby, contribute to preparation noise. From a mass-balance perspective, this resembles the isotopic exchange between CO<sub>2</sub> and a small water contaminant: indicating that certain samples cannot be effectively dried, even after several months in a vacuum drier. This effect can be replicated in off-line experiments, allowing for problematic samples to be unambiguously identified without endangering day-to-day lab operations. We further describe laboratory best-practices wherein the risk of this effect is effectively minimized, allowing for rapid identification of problematic samples: for example, the use of carbonate standards with extremely low ∆<sub>47</sub> values (e.g. ETH-1 and ETH-2) before an analytical sequence allows such issues to be rapidly identified. This highlights the importance of analyzing both carbonate and equilibrated CO<sub>2</sub> standard materials, as these effects could not otherwise be easily identified and eliminated. We present this report in expectation that it will assist other laboratories to improve data quality, as well as to start a conversation about the potential necessity for additional carbonate standards with “exotic” bulk and clumped isotope compositions.</div></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"694 ","pages":"Article 123012"},"PeriodicalIF":3.6000,"publicationDate":"2025-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Isotopic resetting of CO2 in the presence of carbonate samples: Implications for oxygen- and clumped-isotope analyses\",\"authors\":\"Philip Staudigel , Miguel Bernecker , Allison Curley , Niels Meijer , Lkhamsuren Bayarjargal , Martin Dietzel , Jens Fiebig\",\"doi\":\"10.1016/j.chemgeo.2025.123012\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Exchange between CO<sub>2</sub> and water-containing phases is a consistent problem during oxygen and clumped isotope analysis of carbonate-derived CO<sub>2</sub>. Here, we have identified numerous natural and synthetic carbonates and carbonate-bearing materials that consistently reset the δ<sup>18</sup>O, ∆<sub>47</sub> and ∆<sub>48</sub> values of analyte CO<sub>2</sub> during acidification in a common acid bath and, thereby, contribute to preparation noise. From a mass-balance perspective, this resembles the isotopic exchange between CO<sub>2</sub> and a small water contaminant: indicating that certain samples cannot be effectively dried, even after several months in a vacuum drier. This effect can be replicated in off-line experiments, allowing for problematic samples to be unambiguously identified without endangering day-to-day lab operations. We further describe laboratory best-practices wherein the risk of this effect is effectively minimized, allowing for rapid identification of problematic samples: for example, the use of carbonate standards with extremely low ∆<sub>47</sub> values (e.g. ETH-1 and ETH-2) before an analytical sequence allows such issues to be rapidly identified. This highlights the importance of analyzing both carbonate and equilibrated CO<sub>2</sub> standard materials, as these effects could not otherwise be easily identified and eliminated. We present this report in expectation that it will assist other laboratories to improve data quality, as well as to start a conversation about the potential necessity for additional carbonate standards with “exotic” bulk and clumped isotope compositions.</div></div>\",\"PeriodicalId\":9847,\"journal\":{\"name\":\"Chemical Geology\",\"volume\":\"694 \",\"pages\":\"Article 123012\"},\"PeriodicalIF\":3.6000,\"publicationDate\":\"2025-08-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Chemical Geology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0009254125004024\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Geology","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0009254125004024","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
Isotopic resetting of CO2 in the presence of carbonate samples: Implications for oxygen- and clumped-isotope analyses
Exchange between CO2 and water-containing phases is a consistent problem during oxygen and clumped isotope analysis of carbonate-derived CO2. Here, we have identified numerous natural and synthetic carbonates and carbonate-bearing materials that consistently reset the δ18O, ∆47 and ∆48 values of analyte CO2 during acidification in a common acid bath and, thereby, contribute to preparation noise. From a mass-balance perspective, this resembles the isotopic exchange between CO2 and a small water contaminant: indicating that certain samples cannot be effectively dried, even after several months in a vacuum drier. This effect can be replicated in off-line experiments, allowing for problematic samples to be unambiguously identified without endangering day-to-day lab operations. We further describe laboratory best-practices wherein the risk of this effect is effectively minimized, allowing for rapid identification of problematic samples: for example, the use of carbonate standards with extremely low ∆47 values (e.g. ETH-1 and ETH-2) before an analytical sequence allows such issues to be rapidly identified. This highlights the importance of analyzing both carbonate and equilibrated CO2 standard materials, as these effects could not otherwise be easily identified and eliminated. We present this report in expectation that it will assist other laboratories to improve data quality, as well as to start a conversation about the potential necessity for additional carbonate standards with “exotic” bulk and clumped isotope compositions.
期刊介绍:
Chemical Geology is an international journal that publishes original research papers on isotopic and elemental geochemistry, geochronology and cosmochemistry.
The Journal focuses on chemical processes in igneous, metamorphic, and sedimentary petrology, low- and high-temperature aqueous solutions, biogeochemistry, the environment and cosmochemistry.
Papers that are field, experimentally, or computationally based are appropriate if they are of broad international interest. The Journal generally does not publish papers that are primarily of regional or local interest, or which are primarily focused on remediation and applied geochemistry.
The Journal also welcomes innovative papers dealing with significant analytical advances that are of wide interest in the community and extend significantly beyond the scope of what would be included in the methods section of a standard research paper.