{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,27]],"date-time":"2026-05-27T03:03:16Z","timestamp":1779850996887,"version":"3.53.1"},"reference-count":12,"publisher":"Oxford University Press (OUP)","issue":"5","license":[{"start":{"date-parts":[[2026,3,21]],"date-time":"2026-03-21T00:00:00Z","timestamp":1774051200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,5,26]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Specific absorbance (A\u00a6) is a unitless value defined as the absorbance of a 1% (w\/v) solution measured at a 1 cm path length. Establishing reliable specific absorbance values allows forensic toxicology laboratories to verify the concentration of analytical stock solutions. Designer benzodiazepines have appeared with increasing frequency in forensic casework but often lack validated reference values. This study determined specific absorbance values for bromazolam, etizolam, flualprazolam, and flubromazepam using ultraviolet-visible spectroscopy in an aqueous acidic solution. Measurements were collected in duplicate at three concentrations across three days at the wavelength of maximum absorbance for each compound. Inter-run and intra-run variability were evaluated using the coefficient of variation, and the reliability of the values was classified according to Clarke\u2019s Analysis of Drugs and Poisons criteria. The experimentally derived values reported here provide reference information that may assist laboratories in verifying analytical standards for emerging benzodiazepines.<\/jats:p>","DOI":"10.1093\/jat\/bkag019","type":"journal-article","created":{"date-parts":[[2026,3,21]],"date-time":"2026-03-21T10:24:06Z","timestamp":1774088646000},"source":"Crossref","is-referenced-by-count":0,"title":["Determination of specific absorbance (A\u00a6) for four designer benzodiazepines"],"prefix":"10.1093","volume":"50","author":[{"given":"Bryan Shou-Chung","family":"Ku","sequence":"first","affiliation":[{"name":"School of Criminal Justice and Criminalistics, California State University Los Angeles , Los Angeles, CA 90032,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-6184-7945","authenticated-orcid":false,"given":"Jay R","family":"Vargas","sequence":"additional","affiliation":[{"name":"School of Criminal Justice and Criminalistics, California State University Los Angeles , Los Angeles, CA 90032,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,3,21]]},"reference":[{"key":"2026052622270235300_bkag019-B1","doi-asserted-by":"publisher","first-page":"648","DOI":"10.3390\/neurolint14030053","article-title":"Novel designer benzodiazepines: comprehensive review of evolving clinical and adverse effects","volume":"14","author":"Edinoff","year":"2022","journal-title":"Neurol Int"},{"key":"2026052622270235300_bkag019-B2","doi-asserted-by":"publisher","first-page":"668","DOI":"10.1093\/jat\/bkad036","article-title":"Increasing prevalence of designer benzodiazepines in impaired driving: a 5-year analysis from 2017 to 2021","volume":"47","author":"Papsun","year":"2023","journal-title":"J Anal Toxicol"},{"key":"2026052622270235300_bkag019-B3","author":"Drug Enforcement Agency, Department of Justice","year":"2023"},{"key":"2026052622270235300_bkag019-B4","doi-asserted-by":"publisher","first-page":"2019","DOI":"10.1542\/peds.2019-2953","article-title":"Flualprazolam: report of an outbreak of a new psychoactive substance in adolescents","volume":"146","author":"Blumenberg","year":"2020","journal-title":"Pediatrics"},{"key":"2026052622270235300_bkag019-B5","doi-asserted-by":"publisher","first-page":"111777","DOI":"10.1016\/j.forsciint.2023.111777","article-title":"Fentanyl concentrations in ligated femoral blood in the presence and absence of NPS benzodiazepine drugs. A review of over 1250 benzo-dope\/fentanyl toxicity cases in Alberta, Canada","volume":"350","author":"Chatterton","year":"2023","journal-title":"Forensic Sci Int"},{"key":"2026052622270235300_bkag019-B6","doi-asserted-by":"publisher","first-page":"e4","DOI":"10.1093\/jat\/bkaa146","article-title":"A case series of etizolam in opioid-related deaths","volume":"45","author":"Gevorkyan","year":"2021","journal-title":"J Anal Toxicol"},{"key":"2026052622270235300_bkag019-B7","doi-asserted-by":"publisher","first-page":"1487","DOI":"10.1111\/add.16520","article-title":"The surge of bromazolam-related fatalities replacing other novel designer benzodiazepines-related fatalities in San Francisco","volume":"119","author":"Rodda","year":"2024","journal-title":"Addiction"},{"key":"2026052622270235300_bkag019-B8","doi-asserted-by":"publisher","first-page":"43","DOI":"10.1093\/jat\/bkae079","article-title":"The rise of bromazolam in postmortem cases from Travis County, TX, and surrounding areas: 2021 to 2023","volume":"49","author":"Ellefsen","year":"2025","journal-title":"J Anal Toxicol"},{"key":"2026052622270235300_bkag019-B9","author":"Drug Enforcement Agency, Department of Justice","year":"2025"},{"key":"2026052622270235300_bkag019-B10","doi-asserted-by":"publisher","first-page":"478","DOI":"10.1093\/jat\/33.8.478","article-title":"Determination of specific absorbance (A|) for Zaleplon (Sonata) by spectrophotometry","volume":"33","author":"Anderson","year":"2009","journal-title":"J Anal Toxicol"},{"key":"2026052622270235300_bkag019-B11","volume-title":"Clark\u2019s Analysis of Drugs and Poisons","author":"Moffat","year":"2011","edition":"4th"},{"key":"2026052622270235300_bkag019-B12","doi-asserted-by":"publisher","first-page":"531","DOI":"10.1093\/jat\/bkz091","article-title":"Determination of specific absorbance (A|) for six psychoactive drugs encountered in forensic toxicology","volume":"44","author":"Tran","year":"2020","journal-title":"J Anal Toxicol"}],"container-title":["Journal of Analytical Toxicology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/jat\/advance-article-pdf\/doi\/10.1093\/jat\/bkag019\/67457934\/bkag019.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jat\/article-pdf\/50\/5\/bkag019\/67457934\/bkag019.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jat\/article-pdf\/50\/5\/bkag019\/67457934\/bkag019.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,27]],"date-time":"2026-05-27T02:27:07Z","timestamp":1779848827000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/jat\/article\/doi\/10.1093\/jat\/bkag019\/8533543"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,21]]},"references-count":12,"journal-issue":{"issue":"5","published-print":{"date-parts":[[2026,5,26]]}},"URL":"https:\/\/doi.org\/10.1093\/jat\/bkag019","relation":{},"ISSN":["1945-2403"],"issn-type":[{"value":"1945-2403","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,5]]},"published":{"date-parts":[[2026,3,21]]},"article-number":"bkag019"}}