Simultaneous determination of seven fluoroquinolones in royal jelly by ultrasonic-assisted extraction and liquid chromatography with fluorescence detection

摘要

A method for the quantitative determination of seven fluoroquinolone antibacterial agents (FQs) used in beekeeping, viz. ciprofloxacin, norfloxacin, ofloxacin, pefloxa_cin, danofloxacin, enrofloxacin, and difloxacin, in royal jelly samples was developed on the basis of high performance liquid chromatography with fluorescence detec_tion. Sample preparation included deproteination, ultrasonic-assisted extraction with a mixed inorganic solution of monopotassium phosphate (KH_2PO_4) and ethyl_enediaminetetraacetic acid disodium salt (Na_2EDTA), and clean-up on a solid-phase extraction cartridge. The extraction procedure was optimized with regard to the amount of inorganic solvent and the duration of sonication for royal jelly as a com_plicated matrix. Overall recoveries for FQs ranged from 85.9 to 99.1% for royal jelly with standard deviations between 2.79 and 6.27%. Limits of quantification were 2_40 ng/g for seven FQs in royal jelly. A total of 57 real royal jelly samples collected from beekeepers and supermarkets were analyzed. The three most abundant honey_bee-use FQs, i. e. ofloxacin, ciprofloxacin, and norfloxacin, were determined in some royal jelly samples in concentrations ranging from 11.9 to 55.6 ng/g. Unexpectedly, however, difloxacin was found at concentrations of about 46.8 ng/g in one sample although it is rarely used in beekeeping. The presented method was successfully applied to quantify FQs in real royal jelly samples.