Development and Optimization of a Simple and Sensitive Method for the Determination of Virginiamycin M1 Antibiotic in Aqueous Media by Capillary Electrophoresis

Abstract Virginiamycin antibiotic is used in Mexico for animal growth promotion, but has been banned in Europe due to risk of resistance development. Giving that monitoring of antibiotics is critical, the objective of this work was to develop an analytical method based on capillary electrophoresis and liquid-liquid extraction, to quantify virginiamycin antibiotic in livestock wastes. Linearity, precision, bias and extraction parameters were evaluated following ISO/IEC 17025 procedures. Method and extraction validation was satisfactorily, with average values of absolute recovery AR = 86%, extraction efficiency EE = 87%, and matrix effects ME = -14%, RSD <15 for concentrations as low as 50 µg/L.