Microextraction by packed sorbent (MEPS)-UHPLC-UV: A simple and efficient method for the determination of five benzodiazepines in an alcoholic beverage.

This article describes a nano-scale method for the determination and quantification of five benzodiazepines (BDZ) in an alcoholic grappa drink (chlordiazepoxide; lorazepam; diazepam; oxazepam; medazepam). BDZ are typically used in drug-facilitated crimes (DFC) for their accessibility and synergistic effects with alcohol. Specimens collected on the crime scene must be rapidly analyzed to prove the crime, though, in most cases, a very small amount is available. Off-line MEPS extraction of diluted grappa samples proved to be an efficient and reliable method for the recovery of the selected compounds. Requiring a very small amount of extraction solvents, MEPS is an environment-friendly technique. LC separation with UV detection was used as the analytical technique because it is simple, robust, relatively economic and easy-to-find in most laboratories. The method was validated in terms of precision, accuracy and recovery. Limits of detection and quantitation were in the range of 0.5-2ng/μL. Linearity (R(2)) spanned from 0.9994 and 1.0000. Intra- and inter-day repeatabilities were lower than 12% at any concentration. Recovery percentages of an equivalent-to-real sample at three different concentrations were between 70.7 and 74.1%.