Inter-laboratory comparison of the analyses of sulphur hexafluoride (SF6) and three chlorofluorocarbons (CFC-11, -12 and -113) in groundwater and an air standard.
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| Title: | Inter-laboratory comparison of the analyses of sulphur hexafluoride (SF6) and three chlorofluorocarbons (CFC-11, -12 and -113) in groundwater and an air standard. |
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| Authors: | Labasque, T.1 thierry.labasque@univ-rennes1.fr, Aquilina, L.1, Vergnaud, V.1, Barbecot, F.2 |
| Source: | Applied Geochemistry. Nov2014, Vol. 50, p118-129. 12p. |
| Subjects: | Sulfur hexafluoride, Chlorofluorocarbons, Groundwater recharge, Aquifers, Tracers (Chemistry), Analytical chemistry, Geochemistry |
| Abstract: | An inter-laboratory comparison exercise involving the environmental tracers used for groundwater dating was organized in 2012 in France. This paper focuses on SF 6 and CFC tracers. Sampling and analytical protocols were compared in three different exercises using: (1) groundwater from a homogeneous aquifer, (2) groundwater from a fractured heterogeneous aquifer and (3) an air standard. The results show good agreement between laboratories (except some outliers) for the aquifers and air standard. Variation in the SF 6 results on the air standard was low (RSD = 2%) compared to CFCs (RSD 3–7%), even though its concentration was two orders of magnitude lower. Results obtained on recent groundwater (recharged post 1980) show that the inter-laboratory uncertainty for groundwater dating with SF 6 is 3–4 years. This large uncertainty is mainly due to sampling and/or analytical problems. For CFCs, the uncertainties obtained from all laboratories were less than 2 years for groundwater recharged between 1965 and 1996. A higher RSD was observed for CFCs with the air standard analysis, as compared to groundwater measurement, which could indicate an additional uncertainty due to inadequate standardization. Different sampling protocols were used by the laboratories (glass bottles, steel cylinders, etc.) but no systematic effect on measurement uncertainty could be attributed to any of these protocols for either CFCs or SF 6 . The better precisions obtained through these exercises indicate that, except for CFC-11 and SF 6 , the corresponding uncertainty in recharge date determination on recent groundwater (1993 – present) is higher than the commonly assumed 1–2 years (i.e., 7 years for CFC-12 and 4 years for CFC-113). These results confirm the need for regular inter-laboratory comparison exercises to improve the analytical and sampling procedures used in groundwater dating. [ABSTRACT FROM AUTHOR] |
| Copyright of Applied Geochemistry is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 99230572 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Inter-laboratory comparison of the analyses of sulphur hexafluoride (SF6) and three chlorofluorocarbons (CFC-11, -12 and -113) in groundwater and an air standard. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Labasque%2C+T%2E%22">Labasque, T.</searchLink><relatesTo>1</relatesTo><i> thierry.labasque@univ-rennes1.fr</i><br /><searchLink fieldCode="AR" term="%22Aquilina%2C+L%2E%22">Aquilina, L.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Vergnaud%2C+V%2E%22">Vergnaud, V.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Barbecot%2C+F%2E%22">Barbecot, F.</searchLink><relatesTo>2</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Applied+Geochemistry%22">Applied Geochemistry</searchLink>. Nov2014, Vol. 50, p118-129. 12p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Sulfur+hexafluoride%22">Sulfur hexafluoride</searchLink><br /><searchLink fieldCode="DE" term="%22Chlorofluorocarbons%22">Chlorofluorocarbons</searchLink><br /><searchLink fieldCode="DE" term="%22Groundwater+recharge%22">Groundwater recharge</searchLink><br /><searchLink fieldCode="DE" term="%22Aquifers%22">Aquifers</searchLink><br /><searchLink fieldCode="DE" term="%22Tracers+%28Chemistry%29%22">Tracers (Chemistry)</searchLink><br /><searchLink fieldCode="DE" term="%22Analytical+chemistry%22">Analytical chemistry</searchLink><br /><searchLink fieldCode="DE" term="%22Geochemistry%22">Geochemistry</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: An inter-laboratory comparison exercise involving the environmental tracers used for groundwater dating was organized in 2012 in France. This paper focuses on SF 6 and CFC tracers. Sampling and analytical protocols were compared in three different exercises using: (1) groundwater from a homogeneous aquifer, (2) groundwater from a fractured heterogeneous aquifer and (3) an air standard. The results show good agreement between laboratories (except some outliers) for the aquifers and air standard. Variation in the SF 6 results on the air standard was low (RSD = 2%) compared to CFCs (RSD 3–7%), even though its concentration was two orders of magnitude lower. Results obtained on recent groundwater (recharged post 1980) show that the inter-laboratory uncertainty for groundwater dating with SF 6 is 3–4 years. This large uncertainty is mainly due to sampling and/or analytical problems. For CFCs, the uncertainties obtained from all laboratories were less than 2 years for groundwater recharged between 1965 and 1996. A higher RSD was observed for CFCs with the air standard analysis, as compared to groundwater measurement, which could indicate an additional uncertainty due to inadequate standardization. Different sampling protocols were used by the laboratories (glass bottles, steel cylinders, etc.) but no systematic effect on measurement uncertainty could be attributed to any of these protocols for either CFCs or SF 6 . The better precisions obtained through these exercises indicate that, except for CFC-11 and SF 6 , the corresponding uncertainty in recharge date determination on recent groundwater (1993 – present) is higher than the commonly assumed 1–2 years (i.e., 7 years for CFC-12 and 4 years for CFC-113). These results confirm the need for regular inter-laboratory comparison exercises to improve the analytical and sampling procedures used in groundwater dating. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Applied Geochemistry is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.apgeochem.2014.03.009 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 12 StartPage: 118 Subjects: – SubjectFull: Sulfur hexafluoride Type: general – SubjectFull: Chlorofluorocarbons Type: general – SubjectFull: Groundwater recharge Type: general – SubjectFull: Aquifers Type: general – SubjectFull: Tracers (Chemistry) Type: general – SubjectFull: Analytical chemistry Type: general – SubjectFull: Geochemistry Type: general Titles: – TitleFull: Inter-laboratory comparison of the analyses of sulphur hexafluoride (SF6) and three chlorofluorocarbons (CFC-11, -12 and -113) in groundwater and an air standard. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Labasque, T. – PersonEntity: Name: NameFull: Aquilina, L. – PersonEntity: Name: NameFull: Vergnaud, V. – PersonEntity: Name: NameFull: Barbecot, F. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 11 Text: Nov2014 Type: published Y: 2014 Identifiers: – Type: issn-print Value: 08832927 Numbering: – Type: volume Value: 50 Titles: – TitleFull: Applied Geochemistry Type: main |
| ResultId | 1 |
