Determination of three kinds of β-agonists in animal feed by high performance liquid chromatography-tandem mass spectrometry

A high performance liquid chromatography-tandem mass spectrophy(HPLC-MS/MS) was developed for determination of three kinds of β-agonists including clenbuterol,ractomine,salbutemol residues in animal feed.The samples were extracted by 0.2 mol/L H3PO4-methanol(20∶80,V/V),and purified by MCX solid-phase extraction column.Formic acid-acetonitrile and formic acid-ammonium acetate buffer were used as mobile phase by gradient elution.The analysis of target compounds was carried out by HPLC-MS/MS under positive electrospray ionization(ESI+) and multiple reaction monitoring(MRM) mode.A matrix matched external standard was used for quantitative analysis.The calibration curves were in good linearity between the peak area and the concentration of 2~200 ng/mL for three kinds of β-agonists with correlation coefficients not less than 0.995.The spiked recoveries ranged from 86.9% to 93.1% with relative standard deviations of 3.9%~8.1%.The proposed method was simple,rapid,sensetive and accutate,it could meet the requirements of residue analysis.