title: Formation of benzoylecgonine isopropyl ester following solid-phase extraction.
abstract: In forensic toxicology general alkaline drug screens typically utilize liquid liquid [LLE] or solid phase extraction [SPE] sample preparation techniques. It is expected that different drugs will be detected when a laboratory changes techniques. In this study, when the authors switched from LLE to SPE they were able to detect benzoylecgonine [BE]. Benzoylecgonine isopropyl ester [BEIE] was also detected. Further investigation demonstrated that the BEIE was formed during sample elution with methylene chloride/isopropanol/ammonium hydroxide. BEIE was not detected if methanol/ammonium hydroxide was used as the elution solvent. Analysts should be aware that BEIE is formed in the presence of BE if elution solvents comprise isopropanol and a strong base. Therefore, use of BEIE as an internal standard in such assays will result in inaccurate quantitation of BE.
authors.affiliation: UMass Memorial, Department of Hospital Labs, Forensic Toxicology, Worcester, MA 01605, USA. Matthew.Juhascik@umassmemorial.org
authors.forename: Matthew
authors.initials: M
authors.lastname: Juhascik
authors.forename: Jessica
authors.initials: J
authors.lastname: Gleba
authors.forename: Amanda
authors.initials: A
authors.lastname: Jenkins
mesh_terms: D064753:Ammonium Hydroxide; D003042:Cocaine / Q000031:analogs & derivatives* / Q000097:blood / Q000302:isolation & purification; D053593:Forensic Toxicology / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006878:Hydroxides / Q000737:chemistry; D059625:Liquid-Liquid Extraction / Q000379:methods*; D000432:Methanol / Q000737:chemistry; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*; D012997:Solvents / Q000737:chemistry
chemical_list: D006878:Hydroxides; D012997:Solvents; D064753:Ammonium Hydroxide; C005618:benzoylecgonine; C572870:benzoylecgonine isopropyl ester; D003042:Cocaine; D000432:Methanol