{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T13:12:26Z","timestamp":1790082746755,"version":"4.0.1"},"reference-count":39,"publisher":"American Chemical Society (ACS)","issue":"37","license":[{"start":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T00:00:00Z","timestamp":1788825600000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-029"},{"start":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T00:00:00Z","timestamp":1788825600000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-037"},{"start":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T00:00:00Z","timestamp":1788825600000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-045"}],"funder":[{"DOI":"10.13039\/501100002855","name":"Ministry of Science and Technology of the People's Republic of China","doi-asserted-by":"publisher","award":["2021YFC2800300"],"award-info":[{"award-number":["2021YFC2800300"]}],"id":[{"id":"10.13039\/501100002855","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100010816","name":"Anhui Provincial Department of Science and Technology","doi-asserted-by":"publisher","award":["202304a05020010"],"award-info":[{"award-number":["202304a05020010"]}],"id":[{"id":"10.13039\/501100010816","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["42606243"],"award-info":[{"award-number":["42606243"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,22]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Dissolved methane in deep-sea cold seeps can vary from background levels to highly enriched seep water over short spatial scales, which requires in situ measurements with both high sensitivity and a wide dynamic range. Single-transition laser absorption measurements often face a trade-off: strong absorption lines improve low-concentration detection but can saturate at high methane concentrations, whereas weak lines extend the measurable range but reduce the sensitivity. We developed a dual-wavelength off-axis integrated cavity output spectroscopy analyzer for the continuous in situ measurement of dissolved methane in deep-sea environments. The system uses methane transitions near 1651 and 1658 nm to combine trace-level detection with high-concentration quantification. Gas-phase calibration showed excellent linearity for both channels (R2 &amp;gt; 0.999), with the 1651 nm channel calibrated over 2\u201320 ppm and the 1658 nm channel calibrated over 10\u20132000 ppm. During continuous measurement of a 10.06 ppm of CH4 standard gas, the concentration precision improved from 0.016 ppm at 20 s to 1.95 ppb at 400 s for the 1651 nm channel and from 0.69 ppm to 52 ppb for the 1658 nm channel. A membrane-based gas extraction module was then calibrated to convert optical measurements to dissolved methane concentrations. Field deployment on a manned submersible in the northern South China Sea resolved near-bottom methane enrichment, rapid vertical attenuation, and localized hotspots exceeding 250 ppm. These results show that the dual-wavelength OA-ICOS strategy can support continuous, quantitative methane measurements across strongly heterogeneous deep-sea seepage environments.<\/jats:p>","DOI":"10.1021\/acs.analchem.6c04761","type":"journal-article","created":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T05:01:42Z","timestamp":1788843702000},"page":"27668-27678","source":"Crossref","is-referenced-by-count":0,"title":["Dual-Wavelength\nOA-ICOS for Sensitive and Wide-Range\nIn Situ Measurement of Dissolved Methane in Deep-Sea Cold Seeps"],"prefix":"10.1021","volume":"98","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-5262-9197","authenticated-orcid":true,"given":"Mingsi","family":"Gu","sequence":"first","affiliation":[{"name":"Hefei Institutes of Physical Science, Chinese Academy of Sciences , , ,","place":["Hefei, China, 230031"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jingru","family":"Chen","sequence":"additional","affiliation":[{"name":"Hefei Institutes of Physical Science, Chinese Academy of Sciences , , ,","place":["Hefei, China, 230031"]},{"name":"University of Science and Technology of China , ,","place":["Hefei, China, 230026"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiajin","family":"Chen","sequence":"additional","affiliation":[{"name":"Hefei Institutes of Physical Science, Chinese Academy of Sciences , , ,","place":["Hefei, China, 230031"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiaoxu","family":"Mei","sequence":"additional","affiliation":[{"name":"Hefei Institutes of Physical Science, Chinese Academy of Sciences , , ,","place":["Hefei, China, 230031"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guishi","family":"Wang","sequence":"additional","affiliation":[{"name":"Hefei Institutes of Physical Science, Chinese Academy of Sciences , , ,","place":["Hefei, China, 230031"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tu","family":"Tan","sequence":"additional","affiliation":[{"name":"Hefei Institutes of Physical Science, Chinese Academy of Sciences , , ,","place":["Hefei, China, 230031"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kun","family":"Liu","sequence":"additional","affiliation":[{"name":"Hefei Institutes of Physical Science, Chinese Academy of Sciences , , ,","place":["Hefei, China, 230031"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaoming","family":"Gao","sequence":"additional","affiliation":[{"name":"Hefei Institutes of Physical Science, Chinese Academy of Sciences , , ,","place":["Hefei, China, 230031"]},{"name":"University of Science and Technology of China , ,","place":["Hefei, China, 230026"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,9,8]]},"reference":[{"issue":"2","key":"2026092208084810600_cit1","doi-asserted-by":"publisher","first-page":"486","DOI":"10.1021\/cr050362v","article-title":"Oceanic\nmethane biogeochemistry","volume":"107","author":"Reeburgh","year":"2007","journal-title":"Chem. 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