{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T16:26:25Z","timestamp":1792772785787,"version":"4.5.0"},"reference-count":31,"publisher":"Oxford University Press (OUP)","issue":"9","funder":[{"DOI":"10.13039\/100005289","name":"National Institute of Justice","doi-asserted-by":"publisher","award":["15PNIJ-23-GG-01426-RESS"],"award-info":[{"award-number":["15PNIJ-23-GG-01426-RESS"]}],"id":[{"id":"10.13039\/100005289","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,26]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Xylazine, a popular compound found independently and in polydrug mixtures throughout the United States, is intended for use in veterinary medicine and not for human consumption. When xylazine is ingested by humans, life-threatening central nervous system depression responses could potentially occur. With its increase in prevalence, several methods of detection were developed within forensic toxicology. Since xylazine is not approved for human clinical use, little is known about its behavior, such as its stability in stored biological matrices. Knowledge of drug stability in biological matrices can provide critical insight into the limitations surrounding specimen storage conditions, which is of great importance in forensic toxicology. This study assessed the stability of xylazine in preserved antemortem and postmortem blood under three storage conditions (23, 2\u20138, and \u221220\u00b0C) at two concentrations (3 and 160\u2009ng\/mL). Once prepared, samples were extracted using a validated protein precipitation procedure and analyzed by liquid chromatography-tandem mass spectrometry. Xylazine was considered stable if the deviation in calculated concentration was within \u00b120% of the Day 0 concentration. When the results of each individual pool prepared were averaged for reporting, the following results were obtained. When stored at 23\u2009\u00b0C in both matrices, xylazine was unstable by Day 7 at 3\u2009ng\/mL and unstable by Day 10 at 160\u2009ng\/mL. When stored between 2 and 8\u00b0C in antemortem blood, xylazine was unstable by Day 10 at 3\u2009ng\/mL and unstable by Day 24 at 160\u2009ng\/mL. When stored between 2 and 8\u00b0C in postmortem blood, xylazine was unstable by Day 29 at both 3 and 160\u2009ng\/mL. When stored at \u221220\u00b0C in antemortem blood, xylazine was unstable by Day 3 at both 3 and 160\u2009ng\/mL. When stored at \u221220\u00b0C in postmortem blood, xylazine was unstable by Day 21 at 3\u2009ng\/mL and unstable by Day 10 at 160\u2009ng\/mL.<\/jats:p>","DOI":"10.1093\/jat\/bkag081","type":"journal-article","created":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T19:17:37Z","timestamp":1789672657000},"source":"Crossref","is-referenced-by-count":0,"title":["Xylazine: evaluation of antemortem and postmortem specimen storage conditions"],"prefix":"10.1093","volume":"50","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-8861-0748","authenticated-orcid":false,"given":"Paige","family":"Riley-Carrier","sequence":"first","affiliation":[{"name":"Virginia Department of Forensic Science Division of Technical Services, , 8850 Times Dispatch Blvd , Mechanicsville, VA 23116,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rebecca","family":"Wagner","sequence":"additional","affiliation":[{"name":"Virginia Department of Forensic Science Division of Technical Services, , 8850 Times Dispatch Blvd , Mechanicsville, VA 23116,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,9,18]]},"reference":[{"key":"2026102309424081800_bkag081-B1","author":"Drug Enforcement Administration","year":"2025"},{"key":"2026102309424081800_bkag081-B2","author":"US Food and Drug Administration","year":"2022"},{"key":"2026102309424081800_bkag081-B3","author":"Drug Enforcement Administration","year":"2022"},{"key":"2026102309424081800_bkag081-B4","author":"National Institute on Drug Abuse","year":"2024"},{"key":"2026102309424081800_bkag081-B5","author":"US Centers for Disease Control and Prevention","year":"2024"},{"key":"2026102309424081800_bkag081-B6","doi-asserted-by":"publisher","first-page":"257","DOI":"10.1007\/BF00539619","article-title":"On the pharmacology of 2-(2,6-dimethylphenylamino)-4H-5,6-dihydro-1,3-thiazine (Bayer 1470), a substance inhibitory for adrenergic and cholinergic neurons","volume":"256","author":"Kroneberg","year":"1967","journal-title":"Naunyn-Schmiedeberg\u2019s Arch Pharmacol"},{"key":"2026102309424081800_bkag081-B7","author":"Office of National Drug Control Policy","year":"2023"},{"key":"2026102309424081800_bkag081-B8","author":"Office of National Drug Control Policy","year":"2023"},{"key":"2026102309424081800_bkag081-B9","author":"Office of National Drug Control Policy","year":"2024"},{"key":"2026102309424081800_bkag081-B10","author":"Code of Virginia-Drug Control Act"},{"key":"2026102309424081800_bkag081-B11","author":"Virginia Criminal Sentencing Commission","year":"2024"},{"key":"2026102309424081800_bkag081-B12","author":"Library of Congress","year":"2025"},{"key":"2026102309424081800_bkag081-B13","author":"Virginia Department of Forensic Science","year":"2025"},{"key":"2026102309424081800_bkag081-B14","doi-asserted-by":"publisher","first-page":"245","DOI":"10.1093\/jat\/25.4.245","article-title":"Severe intoxication with the veterinary tranquilizer xylazine in humans","volume":"25","author":"Hoffmann","year":"2001","journal-title":"J Anal Toxicol"},{"key":"2026102309424081800_bkag081-B15","doi-asserted-by":"publisher","first-page":"482","DOI":"10.1093\/jat\/bkae055","article-title":"Qualitative and quantitative determination of xylazine in oral fluid","volume":"48","author":"Levitas","year":"2024","journal-title":"J Anal Toxicol"},{"key":"2026102309424081800_bkag081-B16","doi-asserted-by":"publisher","first-page":"726","DOI":"10.1016\/j.electacta.2018.10.120","article-title":"Forensic electrochemistry: electrochemical study and quantification of xylazine in pharmaceutical and urine samples","volume":"295","author":"Mendes","year":"2019","journal-title":"Electrochim. Acta"},{"key":"2026102309424081800_bkag081-B17","doi-asserted-by":"publisher","first-page":"9779","DOI":"10.1007\/s00216-013-7419-7","article-title":"Qualitative metabolism assessment and toxicological detection of xylazine, a veterinary tranquilizer and drug of abuse, in rat and human urine using GC\u2013MS, LC\u2013MSn, and LC\u2013HR-MSn","volume":"405","author":"Meyer","year":"2013","journal-title":"Anal Bioanal Chem"},{"key":"2026102309424081800_bkag081-B18","doi-asserted-by":"publisher","first-page":"1325","DOI":"10.1111\/1556-4029.13684","article-title":"Use of xylazine in drug-facilitated crimes","volume":"63","author":"Krongvorakul","year":"2018","journal-title":"J Forensic Sci"},{"key":"2026102309424081800_bkag081-B19","doi-asserted-by":"publisher","first-page":"165","DOI":"10.1093\/jat\/31.3.165","article-title":"Solid-phase extraction and gas chromatographic mass spectrometric determination of the veterinary drug xylazine in human blood","volume":"31","author":"Barroso","year":"2007","journal-title":"J Anal Toxicol"},{"key":"2026102309424081800_bkag081-B20","doi-asserted-by":"publisher","first-page":"544","DOI":"10.1093\/jat\/29.6.544","article-title":"Determination of acepromazine, ketamine, medetomidine, and xylazine in serum: multi-residue screening by liquid chromatography-mass spectrometry","volume":"29","author":"Miksa","year":"2005","journal-title":"J Anal Toxicol"},{"key":"2026102309424081800_bkag081-B21","doi-asserted-by":"publisher","first-page":"T955","DOI":"10.1111\/1750-3841.12144","article-title":"Determination of xylazine and 2,6-xylidine in animal tissues by liquid chromatography\u2014tandem mass spectrometry","volume":"78","author":"Zheng","year":"2013","journal-title":"J Food Sci"},{"key":"2026102309424081800_bkag081-B22","doi-asserted-by":"publisher","first-page":"150","DOI":"10.1093\/jat\/bkae009","article-title":"Analysis of over 250 novel synthetic opioids and xylazine by LC\u2013MS-MS in blood and urine","volume":"48","author":"Diekhans","year":"2024","journal-title":"J Anal Toxicol"},{"key":"2026102309424081800_bkag081-B23","doi-asserted-by":"publisher","first-page":"319","DOI":"10.1093\/jat\/bks02422","article-title":"Simultaneous determination of xylazine, free morphine, codeine, 6-acetylmorphine, cocaine and benzoylecgonine in postmortem blood by UPLC\u2013MS-MS","volume":"36","author":"Ruiz-Colon","year":"2012","journal-title":"J Anal Toxicol"},{"key":"2026102309424081800_bkag081-B24","doi-asserted-by":"publisher","first-page":"295","DOI":"10.1002\/rcm.8041","article-title":"Analysis of ketamine and xylazine in complex matrices using two-dimensional liquid chromatography\/tandem mass spectrometry","volume":"32","author":"Mella","year":"2018","journal-title":"Rapid Commun Mass Spectrom"},{"key":"2026102309424081800_bkag081-B25","author":"United Chemical Technologies","year":"2023"},{"key":"2026102309424081800_bkag081-B26","author":"Reyes","year":"2024"},{"key":"2026102309424081800_bkag081-B27","doi-asserted-by":"publisher","first-page":"124059","DOI":"10.1016\/j.jchromb.2024.124059","article-title":"A quantitative LC-MS\/MS analysis of xylazine, p-fluorofentanyl, fentanyl and fentanyl-related compounds in postmortem blood","volume":"1237","author":"Truver","year":"2024","journal-title":"J Chromatogr B Analyt Technol Biomed Life Sci"},{"key":"2026102309424081800_bkag081-B28","author":"Reyes","year":"2023"},{"key":"2026102309424081800_bkag081-B29","doi-asserted-by":"publisher","first-page":"444","DOI":"10.1093\/jat\/bkv040","article-title":"Simultaneous determination of xylazine and 2,6-xylidine in blood and urine by auto solid-phase extraction and ultra high-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry","volume":"39","author":"Gao","year":"2015","journal-title":"J Anal Toxicol"},{"key":"2026102309424081800_bkag081-B30","doi-asserted-by":"publisher","first-page":"619","DOI":"10.1093\/jat\/bkab094","article-title":"Qualitative LC\u2013Q-TOF analysis of umbilical cord tissue via data-dependent acquisition as an indicator of in utero exposure to toxic adulterating substances","volume":"46","author":"Nelson","year":"2022","journal-title":"J Anal Toxicol"},{"key":"2026102309424081800_bkag081-B31","doi-asserted-by":"publisher","first-page":"87","DOI":"10.1111\/j.1365-2885.1981.tb00715.x","article-title":"The pharmacokinetics of xylazine hydrochloride: an interspecific study","volume":"4","author":"Garcia-Villar","year":"1981","journal-title":"J Vet Pharmacol Ther"}],"container-title":["Journal of Analytical Toxicology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/jat\/advance-article-pdf\/doi\/10.1093\/jat\/bkag081\/71225644\/bkag081.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jat\/article-pdf\/50\/9\/bkag081\/71225644\/bkag081.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jat\/article-pdf\/50\/9\/bkag081\/71225644\/bkag081.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T13:42:49Z","timestamp":1792762969000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/jat\/article\/doi\/10.1093\/jat\/bkag081\/8817217"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9]]},"references-count":31,"journal-issue":{"issue":"9","published-print":{"date-parts":[[2026,9,26]]}},"URL":"https:\/\/doi.org\/10.1093\/jat\/bkag081","relation":{},"ISSN":["1945-2403"],"issn-type":[{"value":"1945-2403","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,9]]},"published":{"date-parts":[[2026,9]]},"article-number":"bkag081"}}