title: 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 1 min on the 1.7 microm Acquity UPLC BEH HILIC column by using isocratic elution with a mobile phase consisting of 10 mmol L(-1) ammonium acetate in acetonitrile-water (95:5, v/v) at a flow rate of 0.5 mL min(-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: 0.25 g of feed sample, 0.5 g of octadecylsilica as solid sorbent and 10 mL 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.
authors.affiliation: Department of Analytical and Environmental Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius, Lithuania.
authors.forename: Giedre
authors.initials: G
authors.lastname: Kesiūnaite
authors.forename: Evaldas
authors.initials: E
authors.lastname: Naujalis
authors.forename: Audrius
authors.initials: A
authors.lastname: Padarauskas
mesh_terms: D002218:Carbadox / Q000032:analysis* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D011810:Quinoxalines / Q000032:analysis* / Q000302:isolation & purification; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*
chemical_list: D011810:Quinoxalines; C013168:olaquindox; D002218:Carbadox