Electrochemical study and quantification of anesthetic xylazine in urine and pharmaceutical formulations

Xylazine is marketed as a veterinary drug and used to sedative and analgesic purposes; being not approved to human use due several side effects [1]. Over the recent years, xylazine has emerged as a drug of abuse and associated as drug-facilitated sexual assaults [1]. Herein, we describe, for the first time, the electrochemical study and quantification method for xylazine using glassy carbon electrode. Xylazine exhibits at least two well-defined and pH-dependent oxidation processes and one reduction peak in the range of pH from 2.0 to 12.0. The simple and accurate quantification method was performed using Differential Pulse Voltammetry and under the optimized experimental conditions, a linear analytical curve was obtained for xylazine concentrations ranging from 0.5 to 256 μmol L–1, with an estimated detection limit of 200 nmol L–1. The proposed method was applied to determination of xylazine in pharmaceutical formulation, and for forensic scenario, a standard addition protocol in urine samples exhibits excellent recovery values in the range of 93 – 103%, demonstrating the potentiality for clinical analysis of xylazine intoxication. We also show the potential use of portable analytical device fabricated on paper platform coupled with graphite leads as an inexpensive electrode material for on-site analysis.