Simultaneous Determination of Melamine and Clenbuterol in Animal Feeds by GC-MS

A simple, sensitive and reliable GC-MS method for the simultaneous determination of clenbuterol and melamine in feeds was developed and validated. Samples were extracted with acetonitrile/50 mM HCl solution (1:1 v/v), then the extract was cleaned by extraction with ethyl acetate and solid phase extraction. The samples were derivatized with bis(trimethylsilyl)trifluoroacetamide. The selected ion mode detection method (197, 285, 327, 342 for melamine derivative, 86, 212, 262, 277 for clenbuterol derivative) was used. Recoveries of 70.8-92.0% were obtained. The detection limits were 0.6 A mu g kg(-1) (melamine) and 2.40 A mu g kg(-1) (clenbuterol) in feeds.