Forensic electrochemistry: the electroanalytical sensing of Rohypnol® (flunitrazepam) using screen-printed graphite electrodes without recourse for electrode or sample pre-treatment

The electroanalytical sensing of Rohypnol (R) (flunitrazepam) is reported for the first time utilising screen-printed graphite electrodes without the requirement for any additional pre-treatment or modification. The methodology is shown to be useful for quantifying low levels (mu g mL(-1)) of Rohypnol (R) in not only buffered solutions but also two internationally favoured drinks: Coca Cola (TM) and the alcopop WKD (TM) without any sample pre-treatment. The current analytical approaches for the sensing of Rohypnol (R) are also summarised within this paper. The niche of this electroanalytical protocol is the lack of the requirement of any pre-treatment of the sample/beverage or electrode modification (cleaning, pretreatment etc.) for the determination of Rohypnol (R) in beverages and offers a potential rapid, cost-effective, yet suitably sensitive and accurate screening solution to the problem posed by coloured drinks to products such as the colour changing 'Smart Cup'.