Abstract:

A GC-MS method was developed for the determination of residues of 6 β -agonists such as clorprenaline, tulobuterol, penbutolol, propranolol, fenoterol, and ractopamine in prepared frozen foods. Minced beef cutlet samples were hydrolyzed by β-glucuronidase in sodium acetate buffer, and the centrifugation supernatant was then subjected to protein precipitation using perchloric acid, extraction using ethyl acetate, and clean up using an MCX column, followed by derivatization with bis (trimethylsilyl)trifluoroacetamide (BSTFA). The analysis was conducted with metoprolol as an internal standard in selected ion monitoring mode. The spiked recoveries of the 6β-agonists ranged 80.1%－94.5%, with a RSD from 4.3% to 11.2%, and their LODs all were 5 μg/kg.

Key words: GC-MS, prepared frozen food, β-agonists