Exploiting adsorption and desorption at solid-liquid interface for the fluorometric monitoring of glibenclamide in adulterated drinks

Nowadays, the use of a drug to modify a person's behavior with criminal intentions has become a growing public concern. In fact, stealthy drink spiking with certain drugs can cause the incapacitation of a potential victim of assault and in extreme cases can even lead to death. Belonging to the group of drugs used to commit drug-facilitated crimes is glibenclamide, which not only exhibits high sedation secondary effects but when subject to an overdose intake can lead to intense hypoglycemic episodes that could end with death. Suicide attempts and homicides through overdose with glibenclamide have already been reported. In this work and for the first time, it was developed a new methodology for detection of glibenclamide in spiked liquid samples (teas) by fluorometry (lambda(ex) = 300 nm: lambda(em) = 404 nm). The novel methodology was also implemented in a miniaturized and portable automatic flow system based in the concept of multipumping with an in-line pre-separation unit. The separation of the drug from the liquid samples was achieved through adsorption of the drug into activated charcoal packed within a mini column followed by elution with a solution composed by ethanol, hydrochloric acid and the surfactant CTAB (70%, 1.0 mol L-1, 0.01 mol L-1, respectively). The results allowed to obtain a linear working range for glibenclamide concentrations of up to 50 mg L-1 (r = 0.9999) and the detection limit was about 0.81 mg L-1 of glibenclamide. (C) 2012 Elsevier B.V. All rights reserved.