Determination of 4 Tetracyclines Residues in Seafoods by Liquid ChromatographyMass Spectrometry

A method for the determination of 4 tetracyclines (tetracycline， oxytetracycline，doxycycline， chlortetracycline) residues in seafood was developed. Sample was extracted with 2% perchloric acid, purified by a solid-phase extraction procedure. Then the reconstituted sample solution was analyzed by UPLC-MS/MS in ESI position mode using the mobile phase with trifluoroacetic acid（TFA）/water and acetonitritrile. The detection limits of chlortetracycline is 0.008 mg•kg^-1, the others are 0.002 mg•kg^-1. The quantification limit of chlortetracycline is 0.02 mg•kg^-1, the others are 0.006 mg•kg^-1. Range of the calibration curve 4 tetracycline is 0.01-0.1 mg•L^-1, and RSD is more than 0.995. The average recoveries from spiked sample at 3 concentrations of 0.05， 0.08， 0.1 mg•kg^-1 range from 50.2% to 91.2%， and RSD is 4.0%-9.2%。