Multiresidue analysis of nine β-agonists in animal muscles by LC-MS/MS based on a new polymer cartridge for sample cleanup.

A novel, sensitive, and reliable LC-MS/MS method for multiresidue analysis of nine β-agonists (salbutamol, terbutaline, cimaterol, fenoterol, clorprenaline, ractopamine, tulobuterol, clenbuterol, and penbuterol) in four farm animal muscles was developed. Muscle matrix was extracted with acetonitrile-10% sodium carbonate solution, and then was subjected to cleanup using a SPE cartridge packed with new polymer synthesized in acetone. Chromatographic separation of the components was performed on a Luna C18 column using 0.1% of formic acid in water and acetonitrile. The mass spectrometer was operated in the positive electrospray mode. Good precision and accuracy were obtained for all analytes (except for fenoterol) at the spiked three levels of 1.0, 10, and 50 μg/kg. The decision limit and detection capability of nine β-agonists ranged from 0.04 to 0.18 and 0.15 to 0.69 μg/kg, respectively. The method developed was successfully applied to the monitoring of nine β-agonists in pork, beef, mutton, and chicken from Chinese markets.