A new screening method for flunitrazepam in vodka and tequila by fluorescence spectroscopy

Eu-MOF-based highly sensitive and selective luminescence probe for trace, in situ and visual detection of flunitrazepam

Flunitrazepam, as an emerging new psychoactive substance classified as a third-generation drug that is more harmful and camouflaged, is gradually proliferating globally. Maliciously used as a criminal tool in homicide and rape cases, it has already caused serious harm to public safety and social stability. Owing to its special molecular structure, low concentration level and rapid metabolic process in the human body, accurate detection of flunitrazepam remains a major challenge, especially for real sample and on-site detection. In this paper, a lanthanide MOF (Eu-MOF) based on bi-ligand was constructed as a luminescence probe and used for the first time to detect trace amounts of flunitrazepam. The 'antenna effect' promotes strong luminescence of Eu-MOF, while the lower LUMO orbital energy level of flunitrazepam allows it to accept electrons from the electron donor leading to quenching of Eu-MOF luminescence. The probe has a high sensitivity and can detect flunitrazepam in the range of 0-800 μM with a detection limit as low as 73 nM. Moreover, flunitrazepam was detected in urine from real samples as well as in a variety of beverages to further validate its accuracy and practicality. The reported Eu-MOF represents one of the pioneering luminescence probes for the detection of flunitrazepam, which offers great promise for the on-site or on-line analysis of flunitrazepam.

A critical review on the assessment of the quality and authenticity of Tequila by different analytical techniques: Recent advances and perspectives

Currently, the authenticity and traceability of Tequila are determined in an inspection process carried out by the Tequila Regulatory Council. However, in recent years, the authorities have seized illegal alcoholic products that are marketed as Tequila without being so, making it necessary to strengthen the current methods of detecting counterfeiting and/or adulteration. Therefore, it is important to establish a review of the current analytical techniques that have been proposed to solve this problem. In this review, emphasis is placed on the analysis of the analytical techniques that have been used to consolidate a profile of authenticity and quality in Tequila, thus highlighting new auxiliary analytical techniques to the current verification process, establishing future validation opportunities in terms of international quality control. The use of isotopic ratios stands out as the most robust technique because it establishes the type of sugar source used and the maturation time of the manufacturing process.

Lab-on-a-screen-printed electrochemical cell for drop-volume voltammetric screening of flunitrazepam in untreated, undiluted alcoholic and soft drinks

Flunitrazepam, also known as "Rohypnol" or "Rophy" among other trade and street names, is an extremely potent benzodiazepine that is prescribed to treat severe insomnia. Due to these attributes, flunitrazepam, when is surreptitiously administered to an alcoholic or soft drink, is associated with "drug-facilitated sexual assault". We report here for the first time, a low cost lab-on-a-screen-printed electrochemical cell (SPC) based on iron-sparked graphite working electrode modified with glucose oxidase (GOx) and glucose hydrogel droplets (GluHD) for the detection of flunitrazepam. Iron-spark modification increases the response of the sensor by ca. 3-fold compared with that of the plain electrode, while an in situ deoxygenation process, based on GOx-glucose enzyme reaction, depletes dissolved oxygen. As a result, the method enables interference free voltammetric measurements of the electro reduction of the nitro group of flunitrazepam at ca. -0.71 to -0.78 V vs. Ag printed pseudo reference electrode depending on the sample's matrix, and the detection of the drug at the sub-millimolar level. GOx/GluHD-FeSPC was directly applied to the drop-volume (∼60 μL) detection of flunitrazepam to a wide range of untreated and undiluted spiked samples (Pepsi cola®, Vodka, Whisky, Tequila, Gin, and Rum) of different acidity (pH 2.3-8.4), and alcohol content up to 40% v/v. Data demonstrate the excellent performance of the sensor for point-of-need screening of flunitrazepam and suggest that GOx/GluHD-FeSPC holds promise as an effective analytical tool to prevent phenomena of covert drug administration.