@article { , title = {Novel reductive-reductive mode electrochemical detection of Rohypnol following liquid chromatography and its determination in coffee}, abstract = {© 2014 Elsevier B.V. Rohypnol (flunitrazepam) has been successfully determined in coffee by high performance liquid chromatography dual electrode detection (LC-DED) in the dual reductive mode. Initial studies were performed to optimise the chromatographic conditions and these were found to be 50\% acetonitrile, 50\% 50mM pH 2.0 phosphate buffer at a flow rate of 0.75mLmin-1, employing a Hypersil C18, 5μm, 250mm×4.6mm column. Cyclic voltammetric studies were made to ascertain the redox behaviour of Rohypnol at a glassy carbon electrode over the pH range 2-12. Hydrodynamic voltammetry was used to optimise the applied potential at the generator and detector cells; these were identified to be -2.4V and +0.8V for the redox mode and -2.4V and -0.1V for the dual reductive mode respectively. A linear range of 0.5-100μgmL-1, with a detection limit of 20ngmL-1 was obtained for the dual reductive mode. Further studies were then performed to identify the optimum conditions required for the LC-DED determination of Rohypnol in beverage samples. A convenient and rapid method for the determination of Rohypnol in beverage samples was developed using a simple sample pre-treatment procedure. A recovery of 95.5\% was achieved for a sample of white coffee fortified at 9.6μgmL-1 Rohypnol.}, doi = {10.1016/j.aca.2014.09.033}, eissn = {1873-4324}, issn = {0003-2670}, journal = {Analytica Chimica Acta}, pages = {222-227}, publicationstatus = {Published}, publisher = {Elsevier}, url = {https://uwe-repository.worktribe.com/output/839714}, volume = {853}, keyword = {Centre for Research in Biosciences, liquid chromatography dual electrode detection, drug facilitated assault, cyclic voltammetry, beverages, Rohypnol}, year = {2015}, author = {Honeychurch, Kevin C. and Davidson, Gwen M. and Brown, Emma and Hart, John P.} }