Immunoaffinity chromatography purification and ultra-high-performance liquid chromatography-tandem mass spectrometry determination of four β-agonists in beef

A highly selective and sensitive method was developed for the simultaneous determination of four β-agonists (clenbuterol, salbutamol, ractopamine and terbutaline) in beef by immunoaffinity chromatography purification coupled to ultra-high-performance LC-MS/MS. The MS/MS conditions, ultra-high-performance LC mobile phase, injection solution, sample purification process and matrix effect were studied to optimise the operation conditions. The limits of detection (LODs) of the instrument for the studied β-agonists ranged from 0.20 to 0.25 µg l(-1), and the LODs of the method for the studied β-agonists ranged from 0.20 to 3.00 µg kg(-1) for beef. Calibration curves were constructed using a standard solution diluted with blank beef matrix. The linear ranges of the calibration curves ranged from 5 to 100 µg kg(-1) and the coefficients of determination were >0.9942 (n = 10) for all four β-agonists. Samples spiked at 5, 10 and 50 µg kg(-1) showed recoveries >72% and RSDs <6.6%. The method is suitable for the simultaneous detection of four β-agonists at trace levels in beef.