Adsorptive Cathodic Stripping Voltammetry for Quantification of Alprazolam

A simple and highly sensitive electrochemical sensor was developed for adsorptive cathodic stripping voltammetry of alprazolam. Based on an electrochemically pretreated glassy carbon electrode, the sensor demonstrated good adsorption and electrochemical reduction of alprazolam. The morphology of the glassy carbon electrode and the electrochemically pretreated glassy carbon electrode were characterized by scanning electron microscopy/energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The electrochemical behaviors of alprazolam were determined by cyclic voltammetry, and the analytical measurements were studied by adsorptive cathodic stripping voltammetry. Optimized operational conditions included the concentration and deposition time of sulfuric acid in the electrochemical pretreatment, preconcentration potential, and preconcentration time. Under optimal conditions, the developed alprazolam sensor displayed a quantification limit of 0.1 mg L-1, a detection limit of 0.03 mg L-1, a sensitivity of 67 mu A mg(-1) L cm(-2) and two linear ranges: 0.1 to 4 and 4 to 20 mg L-1. Sensor selectivity was excellent, and repeatability (%RSD < 4.24%) and recovery (82.0 +/- 0.2 to 109.0 +/- 0.3%) were good. The results of determining alprazolam in beverages with the developed system were in good agreement with results from the gas chromatography-mass spectrometric method.

Automated summary

A simple and highly sensitive electrochemical sensor was developed for alprazolam, showcasing good selectivity, repeatability, and recovery. The sensor operated under optimized conditions and displayed excellent analytical performance in detecting alprazolam in beverages.