{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T09:07:51Z","timestamp":1780304871762,"version":"3.54.0"},"reference-count":15,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T00:00:00Z","timestamp":1775606400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T00:00:00Z","timestamp":1775606400000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["analyticalsciencejournals.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Drug Testing and Analysis"],"published-print":{"date-parts":[[2026,6]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>Hair analysis is increasingly used in forensic toxicology; however, result interpretation may be influenced by cosmetic hair treatments. Although the effects of bleaching, dyeing, and thermal straightening have already been evaluated, data on permanent chemical hair straightening are scarce, particularly under in\u00a0vivo conditions. This case report evaluates the impact of an alkaline\u2010based permanent hair straightening procedure on the determination of an endogenous compound, gamma\u2010hydroxybutyrate (GHB), and an exogenous drug, alprazolam, in hair. Hair samples were collected from a 39\u2010year\u2010old woman before and 1\u2009month after undergoing chemical hair straightening based on ammonium thioglycolate. Adjacent hair strands corresponding to identical temporal windows were analyzed. GHB was quantified in 0.5\u2010cm hair segments using a validated liquid chromatography\u2013tandem mass spectrometry (LC\u2010MS\/MS) method, whereas alprazolam was analyzed in 2\u2010cm segments using a validated LC\u2010MS\/MS method for drugs of abuse and psychoactive pharmaceuticals. All analyzed segments were positive for GHB in both samples. After the straightening procedure, endogenous GHB concentrations showed a pronounced increase compared with pretreatment levels, with fold changes ranging from approximately 6 to 43 in corresponding segments. In contrast, alprazolam concentrations in segments corresponding to the reported period of drug intake decreased by approximately 1.7\u2010 to 2\u2010fold following chemical straightening. This case report demonstrates that permanent chemical hair straightening can produce marked and analyte\u2010dependent effects on hair drug concentrations. These findings emphasize the importance of systematic documentation of cosmetic hair treatments and careful interpretation of hair analysis results in forensic casework, particularly when analyte concentrations are low.<\/jats:p>","DOI":"10.1002\/dta.70071","type":"journal-article","created":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T07:43:21Z","timestamp":1775634201000},"page":"771-776","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Chemical Straightening as a Source of Analytical Variability in Hair Testing: A Dual\u2010Analyte Case Report"],"prefix":"10.1002","volume":"18","author":[{"given":"Miriam","family":"Blanco\u2010Ces","sequence":"first","affiliation":[{"name":"Toxicology Service, Institute of Forensic Sciences Universidade de Santiago de Compostela  Santiago de Compostela Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana","family":"de\u2010Castro\u2010R\u00edos","sequence":"additional","affiliation":[{"name":"Toxicology Service, Institute of Forensic Sciences Universidade de Santiago de Compostela  Santiago de Compostela Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3158-6118","authenticated-orcid":false,"given":"Mar\u00eda","family":"Cobo\u2010Golpe","sequence":"additional","affiliation":[{"name":"Toxicology Service, Institute of Forensic Sciences Universidade de Santiago de Compostela  Santiago de Compostela Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u00c1ngela","family":"L\u00f3pez\u2010Rabu\u00f1al","sequence":"additional","affiliation":[{"name":"Toxicology Service, Institute of Forensic Sciences Universidade de Santiago de Compostela  Santiago de Compostela Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Angelines","family":"Cruz","sequence":"additional","affiliation":[{"name":"Toxicology Service, Institute of Forensic Sciences Universidade de Santiago de Compostela  Santiago de Compostela Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3414-0509","authenticated-orcid":false,"given":"Elena","family":"Lendoiro","sequence":"additional","affiliation":[{"name":"Toxicology Service, Institute of Forensic Sciences Universidade de Santiago de Compostela  Santiago de Compostela Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,4,8]]},"reference":[{"key":"e_1_2_8_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0379\u20100738(96)02047\u20106"},{"key":"e_1_2_8_3_1","doi-asserted-by":"publisher","DOI":"10.1007\/s004140050056"},{"key":"e_1_2_8_4_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.forc.2017.02.004"},{"key":"e_1_2_8_5_1","doi-asserted-by":"publisher","DOI":"10.1111\/ics.12093"},{"key":"e_1_2_8_6_1","doi-asserted-by":"publisher","DOI":"10.1002\/dta.3798"},{"key":"e_1_2_8_7_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.forsciint.2011.11.006"},{"key":"e_1_2_8_8_1","doi-asserted-by":"publisher","DOI":"10.1002\/dta.1648"},{"key":"e_1_2_8_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.forsciint.2016.01.002"},{"key":"e_1_2_8_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.forsciint.2019.02.027"},{"key":"e_1_2_8_11_1","doi-asserted-by":"publisher","DOI":"10.1093\/jat\/bku106"},{"key":"e_1_2_8_12_1","unstructured":"K.Nowak P.Szpot andM.Zawadzki \u201cEvaluation of the Influence of Keratin Hair Straightening on the Detection of Xenobiotics Illustrated With Caffeine and Endogenous GHB: Preliminary Study \u201d Oral Communication presented at [61st Annual Meeting of the International Association of Forensic Toxicologists] [Saint Gallen Switzerland] [2024]. (SOHT O\u20106)."},{"key":"e_1_2_8_13_1","doi-asserted-by":"publisher","DOI":"10.1007\/s11419\u2010015\u20100285\u20106"},{"key":"e_1_2_8_14_1","doi-asserted-by":"publisher","DOI":"10.1002\/bdd.720"},{"key":"e_1_2_8_15_1","doi-asserted-by":"publisher","DOI":"10.1080\/15563650.2017.1379603"},{"key":"e_1_2_8_16_1","doi-asserted-by":"publisher","DOI":"10.1007\/s11419\u2010022\u201000619\u20109"}],"container-title":["Drug Testing and Analysis"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/dta.70071","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/dta.70071","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/dta.70071","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T08:36:26Z","timestamp":1780302986000},"score":1,"resource":{"primary":{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/10.1002\/dta.70071"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,8]]},"references-count":15,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2026,6]]}},"alternative-id":["10.1002\/dta.70071"],"URL":"https:\/\/doi.org\/10.1002\/dta.70071","archive":["Portico"],"relation":{},"ISSN":["1942-7603","1942-7611"],"issn-type":[{"value":"1942-7603","type":"print"},{"value":"1942-7611","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,8]]},"assertion":[{"value":"2025-12-23","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-03-24","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-04-08","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}