RESUMO
An analytical method was developed to simultaneously determine the residues of four ß2-agonists in animal foods by high performance liquid chromatography/electrospray-tandem mass spectrometry (HPLC-MS/MS). Samples were extracted with 5% (mass fraction) trichloracetic acid, and then cleaned up by two solid phase extraction cartridges (HLB and ProElut PXC). Quantification of the four ß2-agonists was achieved by HPLC-MS/MS in multiple reaction monitoring (MRM) using internal standard method. The limits of detection (S/N=3) of clenbuterol, salbutamol, ractopamine and terbutaline were 0. 05, 0. 05, 0. 05 and 0. 2 µg/kg, and the limits of quantification (S/N= 10) were 0. 25, 0. 25, 0. 1 and 0. 5 µg/kg, respectively. The average recoveries of the four ß2-agonists spiked in blank samples at the spiked levels of 2. 5, 5 and 10 µg/kg were 90. 3%-120. 5% with the relative standard deviation (RSD) range of 1. 60%-9. 33%. The method is reliable, sensitive, good recovery and repeatability. It is suitable for the determination of the residues of the four ß2-agonists in animal foods.
