- Acknowledgements: The authors gratefully acknowledge the financial support of the Andalusian Government (Junta de Andalucía) for supporting this work (Excellence Project Ref: P12-AGR-1647). CTC thanks to the Excellence Project Ref: P12-AGR-1647 for a predoctoral fellowship. DMG acknowledges MINECO for his Juan de la Cierva postdoctoral research contract (ref. JCI-2014–19573). FJL is grateful for personal funding through the Special Research Program of the University of Granada.
- Authors: C. Tejada-Casado, D. Moreno-González, M. del Olmo-Iruela, A.M. García-Campaña, F.J. Lara
- Reference: Talanta 175 (2017) 542-549.
A new method based on micellar electrokinetic chromatography-tandem mass spectrometry (MEKC-MS/MS) has been developed for the identification and simultaneous quantification of thirteen benzimidazoles in animal urine. In order to obtain an appropriate separation with the highest sensitivity, different electrophoretic parameters were evaluated. Under optimum conditions, the separation was performed using ammonium perfluorooctanoate as volatile surfactant and electrophoretic buffer (50 mM, pH 9). To increase the sensitivity, a stacking mode named sweeping was applied, using water as injection solvent at 50 mbar for 75 s, obtaining sensitivity enhancement factors from 50 to 181. The method was applied to different animal urine samples, including sheep, cow and goat. The sample treatment consisted of a 1:10 (v/v) dilution with water. Calibration using sheep urine samples can be used for both goat and cow urine samples with a relative bias below 25% and relative standard deviations lower than 8%. The limits of detection were below 70 µg L−1. As a result, the applicability of this rapid, simple, sensitive, and environmentally friendly method for therapeutic drug monitoring of benzimidazoles based on the analysis of animal urine has been demonstrated.
