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<front>
<journal-meta>
<journal-id journal-id-type="publisher">EGUsphere</journal-id>
<journal-title-group>
<journal-title>EGUsphere</journal-title>
<abbrev-journal-title abbrev-type="publisher">EGUsphere</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">EGUsphere</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub"></issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/egusphere-2026-2188</article-id>
<title-group>
<article-title>Comparison of Modified Bligh-Dyer and Ultrasonic Organic Solvent Methods for GDGT Extraction from Surface Sediments of Lakes with Different Salinities</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Miao</surname>
<given-names>Rui</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Shi</surname>
<given-names>Ning</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zhao</surname>
<given-names>Zenghao</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Liu</surname>
<given-names>Hu</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Li</surname>
<given-names>Xiangzhong</given-names>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Wang</surname>
<given-names>Huanye</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi&apos;an 710061, China</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>University of Chinese Academy of Sciences, Beijing 100049, China</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>School of Water and Environment, Chang&apos;an University, Xi&apos;an 710064, China</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of the Ministry of Education, Chang&apos;an University, Xi&apos;an 710064, China</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Yunnan Key Laboratory of Earth System Science, School of Earth Science, Yunnan University, Kunming 650500, China</addr-line>
</aff>
<pub-date pub-type="epub">
<day>28</day>
<month>04</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>28</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Rui Miao et al.</copyright-statement>
<copyright-year>2026</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-2188/">This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-2188/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-2188/egusphere-2026-2188.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-2188/egusphere-2026-2188.pdf</self-uri>
<abstract>
<p>Accurately quantifying core lipid (CL) and intact polar lipid (IPL) GDGTs is essential for investigating the sources of GDGTs and their responses to climatic and environmental changes in lacustrine systems. However, systematic comparisons of the performance of different methods for extracting GDGTs (both abundance and distribution) from lake sediments remain limited. In this study, we compared two ultrasonic organic solvent extraction methods, including a stepwise gradient extraction with dichloromethane/methanol (DCM/MeOH) solvent mixtures of different polarities and a single solvent extraction with DCM&lt;span&gt;&amp;thinsp;&lt;/span&gt;:&lt;span&gt;&amp;thinsp;&lt;/span&gt;MeOH (9&lt;span&gt;&amp;thinsp;&lt;/span&gt;:&lt;span&gt;&amp;thinsp;&lt;/span&gt;1, v&lt;span&gt;&amp;thinsp;&lt;/span&gt;:&lt;span&gt;&amp;thinsp;&lt;/span&gt;v), and two modified Bligh-Dyer (BD) methods (phosphate buffer; trichloroacetic acid) for extracting CL-GDGTs and IPL-GDGTs from saline and freshwater lake sediments. The results showed that, for CL-GDGTs, stepwise gradient extraction yielded the highest recovery, whereas no significant differences were observed in the CL-derived GDGTs proxies among the different extraction methods. For IPL-GDGTs, the BD (phosphate buffer) method achieved the highest recovery for isoprenoid GDGTs (isoGDGTs), while stepwise gradient extraction was most effective for extracting branched GDGTs (brGDGTs) and archaeol from saline lake sediments. Moreover, the consistently lower relative abundance of crenarchaeol to other isoGDGTs in CLs than in IPLs for all methods suggests that crenarchaeol is primarily produced in the lake water column, whereas other isoGDGTs have a relatively greater autochthonous production within the sediments or at the water-sediment interface. In saline lake sediments, we also observed higher relatively abundance of &amp;ge;&lt;span&gt;&amp;thinsp;&lt;/span&gt;7-methyl brGDGTs and tetramethylated brGDGTs in IPLs than in CLs, indicating that their source bacteria are active at the water-sediment interface or in the sediments of saline lakes. These findings will provide insights for the quantitative analysis of GDGTs in lake sediments and for the study of their sources in lacustrine environments.</p>
</abstract>
<counts><page-count count="28"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>National Natural Science Foundation of China</funding-source>
<award-id>42273030</award-id>
</award-group>
<award-group id="gs2">
<funding-source>National Key Research and Development Program of China</funding-source>
<award-id>2023YFF0804300</award-id>
</award-group>
</funding-group>
</article-meta>
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