Matrix solid-phase dispersion extraction of carbadox and olaquindox in feed followed by hydrophilic interaction ultra-high-pressure liquid chromatographic analysis

Abstract

A new method involving matrix solid-phase dispersion (MSPD) extraction and hydrophilic interaction ultra-high-pressure liquid chromatography (HILIC-UHPLC) with photodiode array detection was developed for the determination of carbadox and olaquindox in feed. Separation of carbadox and olaquindox was achieved within 1min on the 1.7μm Acquity UPLC BEH HILIC column by using isocratic elution with a mobile phase consisting of 10mmolL−1 ammonium acetate in acetonitrile–water (95:5, v/v) at a flow rate of 0.5mLmin−1. Optimization of MSPD extraction parameters, such as type of solid sorbent and elution solvent were carried out. Optimal conditions selected for MSPD extraction were: 0.25g of feed sample, 0.5g of octadecylsilica as solid sorbent and 10mL of acetonitrile–methanol (8:2, v/v) as eluting solvent. Both analytes provided average recoveries from spiked feed samples ranging from 89.1 to 98.4% with relative standard deviations less than 10%. Obtained performance characteristics are comparable to those achieved by liquid–liquid extraction-HPLC with the advantages of being simpler and significantly faster.