Michael Naylor Hudgins, Todd K Knobbe, Julia Hubbard, Andrew Steele, Justin G Park, Morgan F Schaller
{"title":"利用共焦拉曼光谱对方解石流体包裹体中的碳酸盐物种浓度、pH 值和 pCO2 进行原位定量。","authors":"Michael Naylor Hudgins, Todd K Knobbe, Julia Hubbard, Andrew Steele, Justin G Park, Morgan F Schaller","doi":"10.1177/00037028241275192","DOIUrl":null,"url":null,"abstract":"<p><p>Carbonate minerals are globally distributed on the modern and ancient Earth and are abundant in terrestrial and marine depositional environments. Fluid inclusions hosted by calcite retain primary signatures of the source fluid geochemistry at the time of mineral formation (i.e., pCO<sub>2</sub>) and can be used to reconstruct paleoenvironments. Confocal laser Raman spectroscopy provides a quick, nondestructive approach to measuring the constituents of fluid inclusions in carbonates and is a reliable method for qualitatively determining composition in both the aqueous and gas phases. Here, we demonstrate a method for accurately quantifying bicarbonate and carbonate ion concentrations (down to 20 mM) and pH (7-11) from calcite fluid inclusions using confocal Raman spectroscopy. Instrument calibrations for carbonate (CO<sub>3</sub><sup>2-</sup>) and bicarbonate (HCO<sub>3</sub><sup>-</sup>) concentrations and pH were performed using stock solutions. We show that the calcite host mineral does not affect the accurate quantification of carbonate solution concentrations and that these parameters can be used to estimate the pH and pCO<sub>2</sub> of a solution entrapped within a fluid inclusion. We apply the technique to Icelandic spar calcite and find a [CO<sub>3</sub><sup>2-</sup>] = 0.11, [HCO<sub>3</sub><sup>-</sup>] = 0.17, pH = 10.1, and CO<sub>2</sub> parts per million = 2217. The presence of gaseous Raman bands for CO<sub>2</sub>, CH<sub>4</sub>, and H<sub>2</sub>S suggests that the mineral precipitated in a reducing environment.</p>","PeriodicalId":8253,"journal":{"name":"Applied Spectroscopy","volume":null,"pages":null},"PeriodicalIF":2.2000,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"In Situ Quantification of Carbonate Species Concentrations, pH, and pCO<sub>2</sub> in Calcite Fluid Inclusions Using Confocal Raman Spectroscopy.\",\"authors\":\"Michael Naylor Hudgins, Todd K Knobbe, Julia Hubbard, Andrew Steele, Justin G Park, Morgan F Schaller\",\"doi\":\"10.1177/00037028241275192\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Carbonate minerals are globally distributed on the modern and ancient Earth and are abundant in terrestrial and marine depositional environments. Fluid inclusions hosted by calcite retain primary signatures of the source fluid geochemistry at the time of mineral formation (i.e., pCO<sub>2</sub>) and can be used to reconstruct paleoenvironments. Confocal laser Raman spectroscopy provides a quick, nondestructive approach to measuring the constituents of fluid inclusions in carbonates and is a reliable method for qualitatively determining composition in both the aqueous and gas phases. Here, we demonstrate a method for accurately quantifying bicarbonate and carbonate ion concentrations (down to 20 mM) and pH (7-11) from calcite fluid inclusions using confocal Raman spectroscopy. Instrument calibrations for carbonate (CO<sub>3</sub><sup>2-</sup>) and bicarbonate (HCO<sub>3</sub><sup>-</sup>) concentrations and pH were performed using stock solutions. We show that the calcite host mineral does not affect the accurate quantification of carbonate solution concentrations and that these parameters can be used to estimate the pH and pCO<sub>2</sub> of a solution entrapped within a fluid inclusion. We apply the technique to Icelandic spar calcite and find a [CO<sub>3</sub><sup>2-</sup>] = 0.11, [HCO<sub>3</sub><sup>-</sup>] = 0.17, pH = 10.1, and CO<sub>2</sub> parts per million = 2217. The presence of gaseous Raman bands for CO<sub>2</sub>, CH<sub>4</sub>, and H<sub>2</sub>S suggests that the mineral precipitated in a reducing environment.</p>\",\"PeriodicalId\":8253,\"journal\":{\"name\":\"Applied Spectroscopy\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.2000,\"publicationDate\":\"2024-10-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Applied Spectroscopy\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://doi.org/10.1177/00037028241275192\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2024/9/5 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q2\",\"JCRName\":\"INSTRUMENTS & INSTRUMENTATION\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Spectroscopy","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1177/00037028241275192","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/9/5 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"INSTRUMENTS & INSTRUMENTATION","Score":null,"Total":0}
In Situ Quantification of Carbonate Species Concentrations, pH, and pCO2 in Calcite Fluid Inclusions Using Confocal Raman Spectroscopy.
Carbonate minerals are globally distributed on the modern and ancient Earth and are abundant in terrestrial and marine depositional environments. Fluid inclusions hosted by calcite retain primary signatures of the source fluid geochemistry at the time of mineral formation (i.e., pCO2) and can be used to reconstruct paleoenvironments. Confocal laser Raman spectroscopy provides a quick, nondestructive approach to measuring the constituents of fluid inclusions in carbonates and is a reliable method for qualitatively determining composition in both the aqueous and gas phases. Here, we demonstrate a method for accurately quantifying bicarbonate and carbonate ion concentrations (down to 20 mM) and pH (7-11) from calcite fluid inclusions using confocal Raman spectroscopy. Instrument calibrations for carbonate (CO32-) and bicarbonate (HCO3-) concentrations and pH were performed using stock solutions. We show that the calcite host mineral does not affect the accurate quantification of carbonate solution concentrations and that these parameters can be used to estimate the pH and pCO2 of a solution entrapped within a fluid inclusion. We apply the technique to Icelandic spar calcite and find a [CO32-] = 0.11, [HCO3-] = 0.17, pH = 10.1, and CO2 parts per million = 2217. The presence of gaseous Raman bands for CO2, CH4, and H2S suggests that the mineral precipitated in a reducing environment.
期刊介绍:
Applied Spectroscopy is one of the world''s leading spectroscopy journals, publishing high-quality peer-reviewed articles, both fundamental and applied, covering all aspects of spectroscopy. Established in 1951, the journal is owned by the Society for Applied Spectroscopy and is published monthly. The journal is dedicated to fulfilling the mission of the Society to “…advance and disseminate knowledge and information concerning the art and science of spectroscopy and other allied sciences.”