{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,27]],"date-time":"2026-09-27T07:57:42Z","timestamp":1790495862087,"version":"4.1.0"},"reference-count":22,"publisher":"SAGE Publications","license":[{"start":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T00:00:00Z","timestamp":1784678400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T00:00:00Z","timestamp":1784678400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Appl Spectrosc"],"abstract":"<jats:p>Laser\u2013induced Fluorescence (LIF) is widely employed in combustion research for various diagnostic applications, including the simultaneous visualisation of liquid and vapour phase as well as temperature and concentration measurements. For quantitative LIF diagnostics, liquid fuels are often doped with fluorescent tracers whose spectroscopic properties must be carefully characterised. While numerous dyes have been investigated in polar solvents like water or ethanol, data for nonpolar fluids like common combustion fuels remain scarce. However, solvent polarity is known to significantly affect solubility, their optical response, spectral shape as well as influencing shifts in absorption and emission maxima. This study provides a systematic comparison of the fluorescent dyes Coumarin 152, Fluoranthene, DCM, and Pyrromethene 567 with respect to their suitability for quantitative two-colour LIF thermometry in combustion diagnostics and single\u2013droplet evaporation experiments. Measurements are conducted in three nonpolar fuels: a fossil (B0) diesel and two synthetic alternatives, gas\u2013to\u2013liquid (GtL) and power\u2013to\u2013liquid (PtL) diesel. A systematic comparison of dye performance is presented, including solubility limits as well as temperature\u2013dependent LIF response under 355 and 532\u2005nm excitation. Despite its comparatively lower solubility, Pyrromethene 567 exhibits high signal intensities and a pronounced temperature\u2013dependent response, qualifying it as suitable tracer for 2\u2013colour LIF (2c\u2013LIF) measurements in these fuels. The results support an informed selection of tracer\u2013fuel combinations and contribute to improved reliability of LIF\u2013based temperature and concentration measurements in nonpolar mixtures and real fuel application.<\/jats:p>","DOI":"10.1177\/00037028261474247","type":"journal-article","created":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T18:47:08Z","timestamp":1784746028000},"update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":0,"title":["Absorption and Fluorescence Properties of Tracer Dyes in Complex Nonpolar Hydrocarbon Mixtures"],"prefix":"10.1177","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-2414-8595","authenticated-orcid":false,"given":"Mirko","family":"Geiger","sequence":"first","affiliation":[{"name":"Chair of Engineering Thermodynamics and Transport Processes, University of Bayreuth, Universit\u00e4tsstra\u00dfe 30, 95440 Bayreuth, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dieter","family":"Br\u00fcggemann","sequence":"additional","affiliation":[{"name":"Chair of Engineering Thermodynamics and Transport Processes, University of Bayreuth, Universit\u00e4tsstra\u00dfe 30, 95440 Bayreuth, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2026,7,22]]},"reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.3390\/en16062834"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.3390\/en17050981"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1021\/acsomega.5c05513"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.fuel.2018.08.031"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1366\/0003702001949744"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.pecs.2004.08.002"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.3390\/s24030724"},{"key":"e_1_3_2_9_2","unstructured":"D\u00fcwel I.. Spray combustion diagnostics with tracer-based laser-induced fluorescence imaging. Heidelberg University Library 2007."},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.1364\/AO.419684"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1021\/jp021543t"},{"key":"e_1_3_2_12_2","doi-asserted-by":"crossref","unstructured":"Mueller T. Wigger S. Fuesser H.-J. Kaiser S.. \u201cDevelopment of a LIF-Imaging System for Simultaneous High-Speed Visualization of Liquid Fuel and Oil Films in an Optically Accessible DISI Engine\u201d. In: WCX World Congress Experience. SAE International 2018.","DOI":"10.4271\/2018-01-0634"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/0584-8539(93)80117-S"},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.copbio.2023.102919"},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00348-020-2909-9"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1364\/AO.54.007013"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.3390\/molecules28031136"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.1088\/2040-8986\/acf5fc"},{"key":"e_1_3_2_19_2","volume-title":"Analysis of internal diesel injector deposit formation by separation science and mass spectrometry","author":"Patel Krina","year":"2016","unstructured":"Patel Krina. Analysis of internal diesel injector deposit formation by separation science and mass spectrometry. University of Southampton, 2016."},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1007\/978-0-387-46312-4"},{"key":"e_1_3_2_21_2","doi-asserted-by":"publisher","DOI":"10.1063\/1.452460"},{"key":"e_1_3_2_22_2","article-title":"Optical and Laser-based in situ Diagnostics in Lab-scale and Pilot-scale Spray Flames for Nanoparticle Synthesis","author":"Prenting Markus Michael","year":"2024","unstructured":"Prenting Markus Michael. Optical and Laser-based in situ Diagnostics in Lab-scale and Pilot-scale Spray Flames for Nanoparticle Synthesis. Duisburg, 2024.","journal-title":"Duisburg"},{"key":"e_1_3_2_23_2","doi-asserted-by":"publisher","DOI":"10.1016\/1010-6030(90)87021-3"}],"container-title":["Applied Spectroscopy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/00037028261474247","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/00037028261474247","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/00037028261474247","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,27]],"date-time":"2026-09-27T07:19:14Z","timestamp":1790493554000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/00037028261474247"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,22]]},"references-count":22,"alternative-id":["10.1177\/00037028261474247"],"URL":"https:\/\/doi.org\/10.1177\/00037028261474247","relation":{},"ISSN":["0003-7028","1943-3530"],"issn-type":[{"value":"0003-7028","type":"print"},{"value":"1943-3530","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,22]]},"article-number":"00037028261474247"}}