{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,7]],"date-time":"2026-02-07T20:24:45Z","timestamp":1770495885093,"version":"3.49.0"},"reference-count":66,"publisher":"PeerJ","license":[{"start":{"date-parts":[[2025,10,8]],"date-time":"2025-10-08T00:00:00Z","timestamp":1759881600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000038","name":"Natural Sciences and Engineering Research Council of Canada","doi-asserted-by":"crossref","award":["2020-04740"],"award-info":[{"award-number":["2020-04740"]}],"id":[{"id":"10.13039\/501100000038","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001804","name":"Canada Research Chairs Program","doi-asserted-by":"crossref","award":["950-231012"],"award-info":[{"award-number":["950-231012"]}],"id":[{"id":"10.13039\/501100001804","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:p>Stable isotope analysis of skin collagen is useful for detecting short-term or seasonal diet. Preparation of skin for stable isotope analysis varies across laboratories, and this may impact the comparability of data. It is important to understand the effects of different preparatory protocols on the stable isotopic and elemental compositions of skin samples. Using a Eurovector 3,300 elemental analyzer coupled to a Nu Horizon isotope ratio mass spectrometer, we tested the impact of three treatment variants (refluxing at three temperatures to remove non-collagenous proteins, treatment with sodium hydroxide (NaOH), and chemical lipid extraction using 2:1 chloroform:methanol) on the stable isotope (<jats:italic>\u03b4<\/jats:italic><jats:sup>13<\/jats:sup>carbon (C) and <jats:italic>\u03b4<\/jats:italic><jats:sup>15<\/jats:sup>nitrogen (N)) and elemental (wt% C, and wt% N) composition of pig (<jats:italic>Sus scrofa domesticus<\/jats:italic>) skin. The refluxing step produced pig skin with higher <jats:italic>\u03b4<\/jats:italic><jats:sup>13<\/jats:sup>C values, lower C:N<jats:sub>Atomic<\/jats:sub> ratios, less variable C:N<jats:sub>Atomic<\/jats:sub> ratios, wt% C, and wt% N. The chemical lipid extraction also produced higher, more reliable <jats:italic>\u03b4<\/jats:italic><jats:sup>13<\/jats:sup>C values and lower, less variable C:N<jats:sub>Atomic<\/jats:sub> ratios. The isotopic data in the lipid-extracted and refluxed samples were more consistent in the refluxed samples than the non-refluxed and non-lipid-extracted samples, as determined by the elemental compositions.<\/jats:p>","DOI":"10.7717\/peerj.20152","type":"journal-article","created":{"date-parts":[[2025,10,8]],"date-time":"2025-10-08T08:38:38Z","timestamp":1759912718000},"page":"e20152","source":"Crossref","is-referenced-by-count":1,"title":["Solubilization of skin collagen improves the accuracy and reliability of stable isotope measurements"],"prefix":"10.7717","volume":"13","author":[{"given":"Alexandra A.Y.","family":"Derian","sequence":"first","affiliation":[{"name":"Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ryan","family":"Pawlowski","sequence":"additional","affiliation":[{"name":"Anthropology, Trent University, Peterborough, Ontario, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Paul","family":"Szpak","sequence":"additional","affiliation":[{"name":"Anthropology, Trent University, Peterborough, Ontario, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"4443","published-online":{"date-parts":[[2025,10,8]]},"reference":[{"issue":"12","key":"10.7717\/peerj.20152\/ref-1","doi-asserted-by":"publisher","first-page":"3543","DOI":"10.1002\/ar.24908","article-title":"Comparison of vertebrate skin structure at class level: a review","volume":"305","author":"Akat","year":"2022","journal-title":"The Anatomical Record"},{"issue":"Pt 15","key":"10.7717\/peerj.20152\/ref-2","doi-asserted-by":"publisher","first-page":"2349","DOI":"10.1242\/jeb.027565","article-title":"Carbon and nitrogen stable isotope turnover rates and diet-tissue discrimination in Florida manatees (Trichechus manatus latirostris)","volume":"212","author":"Alves-Stanley","year":"2009","journal-title":"The Journal of Experimental Biology"},{"issue":"4","key":"10.7717\/peerj.20152\/ref-3","doi-asserted-by":"publisher","first-page":"431","DOI":"10.1016\/0305-4403(90)90007-r","article-title":"Preparation and characterization of bone and tooth collagen for isotopic analysis","volume":"17","author":"Ambrose","year":"1990","journal-title":"The Journal of Archaeological Science"},{"issue":"18","key":"10.7717\/peerj.20152\/ref-4","doi-asserted-by":"publisher","first-page":"1551","DOI":"10.1002\/rcm.7936","article-title":"Isotopic homogeneity throughout the skin in small cetaceans","volume":"31","author":"Arregui","year":"2017","journal-title":"Rapid Communications in Mass Spectrometry"},{"key":"10.7717\/peerj.20152\/ref-5","doi-asserted-by":"publisher","first-page":"59","DOI":"10.1016\/j.seares.2018.07.011","article-title":"An evaluation of whale skin differences and its suitability as a tissue for stable isotope analysis","volume":"140","author":"Borrell","year":"2018","journal-title":"Journal of Sea Research"},{"issue":"358","key":"10.7717\/peerj.20152\/ref-6","doi-asserted-by":"publisher","first-page":"853","DOI":"10.15184\/aqy.2017.98","article-title":"A stable relationship: isotopes and bioarchaeology are in it for the long haul","volume":"91","author":"Britton","year":"2017","journal-title":"Antiquity"},{"issue":"2","key":"10.7717\/peerj.20152\/ref-7","doi-asserted-by":"publisher","first-page":"353","DOI":"10.1017\/s0033822200057477","article-title":"Radiocarbon dating of historical parchments","volume":"55","author":"Brock","year":"2013","journal-title":"Radiocarbon"},{"issue":"2","key":"10.7717\/peerj.20152\/ref-8","doi-asserted-by":"publisher","first-page":"171","DOI":"10.1017\/s0033822200044118","article-title":"Improved collagen extraction by modified Longin method","volume":"30","author":"Brown","year":"1988","journal-title":"Radiocarbon"},{"issue":"8","key":"10.7717\/peerj.20152\/ref-9","doi-asserted-by":"publisher","first-page":"e8686","DOI":"10.1002\/rcm.8686","article-title":"An ideal solution? 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