ABSTRACT
A method was developed for determining residual narasin in chicken tissues by HPLC with post-column derivatization. The samples were extracted with iso-octane. Further cleanup was performed on LC-si cartridge after centrifugation. Then the eluent was dried by nitrogen and residues were dissolved in methanol, water mixture (90∶ 10 v/v). The samples were analyzed on an Inertsil ODS-3 C18 column with a mixture of methanol-acetic acid-water as the mobile phase and vanillin as the derivatization reagent. The detection wavelength was 520 nm. The samples were quantified with the external standard calibration curve method. The limit of detection and the limit of quantification for narasin in chicken tissues were 6.0 μg/kg and 20 μg/kg, respectively. The average recoveries of narasin in chicken tissues were 76.4 %-93.1 %, the intra-assay relative standard deviations were 2.6 %-8.9% and the inter-assay relative standard deviations were 4.7%-9.7% at spiked levels of 20-1800 μg/kg. There was a good linear correlation (the calibration coefficient is above 0.9993) between the peak areas and concentration of narasin in the range of 70-10000 μg/L.