Development of immunoaffinity sample-purification for GC-MS analysis of ractopamine in swine tissue

A method combining immunoaffinity chromatography with gas chromatography-mass spectrometry (GC-MS) has been established for determination of ractopamine residues in swine liver and urine. After clean-up on an immunoaffinity chromatography column, GC-MS analysis revealed recovery from blank swine liver and urine fortified at 2.5-20 ng g(-1) (ng mL(-1) for urine), respectively, was 68.2-78.6 and 76.2-83.1%. The limits of detection and quantification were 0.5 ng g(-1) (or ng mL(-1)) and 2.0 ng g(-1) (or ng mL(-1)), respectively. The procedure was used for analysis of ractopamine residues in samples of swine liver and urine in which the levels were unknown. The amounts detected were 9-216 ng g(-1) (ng mL(-1)).