Determination of scopolamine and butylscopolamine in beverages, urine and Buscopan® tablets samples using electrophoresis microchip with integrated contactless conductivity detection

• Published in: Talanta (Oxford) Vol. 266; no. Pt 1; p. 124960
• Main Authors: Santos, Hellen I., Pinheiro, Kemilly M.P., Richter, Eduardo M., Coltro, Wendell K.T.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2024
• Subjects: Electrochemical detection; Forensic chemistry; Microfluidics; Predatory drugs; Tropane alkaloids; Electrochemical detection; Predatory drugs; Forensic chemistry; Microfluidics; Tropane alkaloids
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2023.124960

The number of cases in which scopolamine (SCO) was used for both recreational and predatory purposes has increased dramatically in recent decades. Linked to this, there is a concern about obtaining SCO through thermal degradation of butylscopolamine (BSCO) – an active ingredient of Buscopan® – a drug sold without a medical prescription. In this study, mixtures containing SCO and BSCO were separated and detected on a microchip electrophoresis (ME) device with integrated capacitively coupled contactless conductivity detection (C4D) using a running buffer composed of 40 mmol L−1 of butyric acid and 25 mmol L−1 of sodium hydroxide (pH 5.0). The separation was performed within ca. 115 s with a resolution of 1.3 and separation efficiency ranging from 1.4 × 105 to 1.5 × 105 theoretical plates m−1. A detection limit of 1.1 μmol L−1 was achieved for both species and the developed method revealed satisfactory repeatability with relative standard deviation (RSD) values for forty-eight injections between 4.8 and 9.4% for peak areas and lower than 3.3% for migration times. Furthermore, inter-day precision was evaluated for sixteen injections (a sequence of four injections performed over four days), and RSD values were less than 6.6% for peak areas and 2.2% for migration times. Satisfactory recovery values (95–114%) were obtained for all evaluated beverage samples (cachaça, vodka, whiskey, beer, Coca-Cola, and grape juice) as well as for artificial urine samples (95–107%). Finally, the conversion of BSCO into SCO was observed after simple heating procedure of Buscopan® sample (not subject to medical prescription), which was successfully confirmed through analysis by capillary electrophoresis coupled to the mass spectrometry (CE-MS). Based on the reported results, the use of ME-C4D devices has demonstrated a huge potential for applications in the forensic chemistry field. [Display omitted] •Scopolamine and butylscopolamine were analyzed using electrophoresis microchips.•The proposed method was applied to beverages, urine and Buscopan® samples.•The conversion of butylscopolamine into scopolamine was investigated and confirmed.•The proposed approach provided fast, portable and low-cost drugs analysis.•Electrophoresis chips are promising tools for forensic and clinical applications.