Formation of benzoylecgonine isopropyl ester following solid-phase extraction.

Matthew Juhascik, Jessica Gleba, Amanda Jenkins

UMass Memorial, Department of Hospital Labs, Forensic Toxicology, Worcester, MA 01605, USA. Matthew.Juhascik@umassmemorial.org

Journal of analytical toxicology 2012 Mar

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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.

Citation

Matthew Juhascik, Jessica Gleba, Amanda Jenkins. Formation of benzoylecgonine isopropyl ester following solid-phase extraction. Journal of analytical toxicology. 2012 Mar;36(2):141-3