UHPLC-MS/MS Determination of Enrofloxacin and Ciprofloxacin in Bean Sprouts

The bean sprout sample blended with homogenizer was extracted ultrasonically with phosphate buffer. The extract was purified with HLB solid phase extraction column, and then eluted with methanol. UHPLC-MS/MS was applied to the determination of enrofloxacin and ciprofloxacin. Agilent Eclipse Plus C₁₈ RRHD chromatographic column was used as stationary phase, and the mixture of methanol and 0.1% (φ) formic acid-2 mmol·L^-1 ammonium acetate solution mixed in different ratios was used as mobile phase in gradient elution. ESI⁺ and multi-reactions monitor mode were adopted in MS/MS. Isotope was used as internal standard. Linearity ranges of enrofloxacin and ciprofloxacin were both found between 0.5 μg·L^-1 and 50.0 μg·L^-1, with detection limit (3S/N) of 0.025 μg·kg^-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 89.2%-101%, with RSDs (n=6) of determined values in the range of 3.3%-9.2%.