Cindy De Jonge, Francien Peterse, Klaas G. J. Nierop, Thomas M. Blattmann, Marcelo Alexandre, Salome Ansanay-Alex, Thomas Austin, Mathieu Babin, Edouard Bard, Thorsten Bauersachs, Jerome Blewett, Brenna Boehman, Isla S. Castañeda, Junhui Chen, Martina L. G. Conti, Sergio Contreras, Julia Cordes, Nina Davtian, Bart van Dongen, Bella Duncan, Felix J. Elling, Valier Galy, Shaopeng Gao, Jens Hefter, Kai-Uwe Hinrichs, Mitchell R. Helling, Mariska Hoorweg, Ellen Hopmans, Juzhi Hou, Yongsong Huang, Arnaud Huguet, Guodong Jia, Cornelia Karger, Brendan J. Keely, Stephanie Kusch, Hui Li, Jie Liang, Julius S. Lipp, Weiguo Liu, Hongxuan Lu, Kai Mangelsdorf, Hayley Manners, Alfredo Martinez Garcia, Guillemette Menot, Gesine Mollenhauer, B. David A. Naafs, Sebastian Naeher, Lauren K. O'Connor, Ethan M. Pearce, Ann Pearson, Zhiguo Rao, Marta Rodrigo-Gámiz, Chris Rosendahl, Frauke Rostek, Rui Bao, Prasanta Sanyal, Florence Schubotz, Wesley Scott, Rahul Sen, Appy Sluijs, Rienk Smittenberg, Ioana Stefanescu, Jia Sun, Paul Sutton, Jess Tierney, Eduardo Tejos, Joan Villanueva, Huanye Wang, Josef Werne, Masanobu Yamamoto, Huan Yang, Aifeng Zhou
{"title":"Interlaboratory Comparison of Branched GDGT Temperature and pH Proxies Using Soils and Lipid Extracts","authors":"Cindy De Jonge, Francien Peterse, Klaas G. J. Nierop, Thomas M. Blattmann, Marcelo Alexandre, Salome Ansanay-Alex, Thomas Austin, Mathieu Babin, Edouard Bard, Thorsten Bauersachs, Jerome Blewett, Brenna Boehman, Isla S. Castañeda, Junhui Chen, Martina L. G. Conti, Sergio Contreras, Julia Cordes, Nina Davtian, Bart van Dongen, Bella Duncan, Felix J. Elling, Valier Galy, Shaopeng Gao, Jens Hefter, Kai-Uwe Hinrichs, Mitchell R. Helling, Mariska Hoorweg, Ellen Hopmans, Juzhi Hou, Yongsong Huang, Arnaud Huguet, Guodong Jia, Cornelia Karger, Brendan J. Keely, Stephanie Kusch, Hui Li, Jie Liang, Julius S. Lipp, Weiguo Liu, Hongxuan Lu, Kai Mangelsdorf, Hayley Manners, Alfredo Martinez Garcia, Guillemette Menot, Gesine Mollenhauer, B. David A. Naafs, Sebastian Naeher, Lauren K. O'Connor, Ethan M. Pearce, Ann Pearson, Zhiguo Rao, Marta Rodrigo-Gámiz, Chris Rosendahl, Frauke Rostek, Rui Bao, Prasanta Sanyal, Florence Schubotz, Wesley Scott, Rahul Sen, Appy Sluijs, Rienk Smittenberg, Ioana Stefanescu, Jia Sun, Paul Sutton, Jess Tierney, Eduardo Tejos, Joan Villanueva, Huanye Wang, Josef Werne, Masanobu Yamamoto, Huan Yang, Aifeng Zhou","doi":"10.1029/2024GC011583","DOIUrl":null,"url":null,"abstract":"<p>Ratios of glycerol dialkyl glycerol tetraethers (GDGT), which are membrane lipids of bacteria and archaea, are at the base of several paleoenvironmental proxies. They are frequently applied to soils as well as lake- and marine sediments to generate records of past temperature and soil pH. To derive meaningful environmental information from these reconstructions, high analytical reproducibility is required. Based on submitted results by 39 laboratories from across the world, which employ a diverse range of analytical and quantification methods, we explored the reproducibility of brGDGT-based proxies (MBT′<sub>5ME</sub>, IR, and #rings<sub>tetra</sub>) measured on four soil samples and four soil lipid extracts. Correct identification and integration of 5- and 6-methyl brGDGTs is a prerequisite for the robust calculation of proxy values, but this can be challenging as indicated by the large inter-interlaboratory variation. The exclusion of statistical outliers improves the reproducibility, where the remaining uncertainty translates into a temperature offset from median proxy values of 0.3–0.9°C and a pH offset of 0.05–0.3. There is no apparent systematic impact of the extraction method and sample preparation steps on the brGDGT ratios. Although reported GDGT concentrations are generally consistent within laboratories, they vary greatly between laboratories. This large variability in brGDGT quantification may relate to variations in ionization efficiency or specific mass spectrometer settings possibly impacting the response of brGDGTs masses relative to that of the internal standard used. While ratio values of GDGT are generally comparable, quantities can currently not be compared between laboratories.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":null,"pages":null},"PeriodicalIF":2.9000,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GC011583","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geochemistry Geophysics Geosystems","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1029/2024GC011583","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Ratios of glycerol dialkyl glycerol tetraethers (GDGT), which are membrane lipids of bacteria and archaea, are at the base of several paleoenvironmental proxies. They are frequently applied to soils as well as lake- and marine sediments to generate records of past temperature and soil pH. To derive meaningful environmental information from these reconstructions, high analytical reproducibility is required. Based on submitted results by 39 laboratories from across the world, which employ a diverse range of analytical and quantification methods, we explored the reproducibility of brGDGT-based proxies (MBT′5ME, IR, and #ringstetra) measured on four soil samples and four soil lipid extracts. Correct identification and integration of 5- and 6-methyl brGDGTs is a prerequisite for the robust calculation of proxy values, but this can be challenging as indicated by the large inter-interlaboratory variation. The exclusion of statistical outliers improves the reproducibility, where the remaining uncertainty translates into a temperature offset from median proxy values of 0.3–0.9°C and a pH offset of 0.05–0.3. There is no apparent systematic impact of the extraction method and sample preparation steps on the brGDGT ratios. Although reported GDGT concentrations are generally consistent within laboratories, they vary greatly between laboratories. This large variability in brGDGT quantification may relate to variations in ionization efficiency or specific mass spectrometer settings possibly impacting the response of brGDGTs masses relative to that of the internal standard used. While ratio values of GDGT are generally comparable, quantities can currently not be compared between laboratories.
期刊介绍:
Geochemistry, Geophysics, Geosystems (G3) publishes research papers on Earth and planetary processes with a focus on understanding the Earth as a system. Observational, experimental, and theoretical investigations of the solid Earth, hydrosphere, atmosphere, biosphere, and solar system at all spatial and temporal scales are welcome. Articles should be of broad interest, and interdisciplinary approaches are encouraged.
Areas of interest for this peer-reviewed journal include, but are not limited to:
The physics and chemistry of the Earth, including its structure, composition, physical properties, dynamics, and evolution
Principles and applications of geochemical proxies to studies of Earth history
The physical properties, composition, and temporal evolution of the Earth''s major reservoirs and the coupling between them
The dynamics of geochemical and biogeochemical cycles at all spatial and temporal scales
Physical and cosmochemical constraints on the composition, origin, and evolution of the Earth and other terrestrial planets
The chemistry and physics of solar system materials that are relevant to the formation, evolution, and current state of the Earth and the planets
Advances in modeling, observation, and experimentation that are of widespread interest in the geosciences.