Quick analysis of β-agonists in urine by solid phase microextraction with headspace derivatization and gas chromatography-mass spectrometry

Clenbuterol in urine was extracted by solid-phase microextraction, and headspace denivatized by N, O-bis ( trimethylsilyl) trifluoroacetamide ( BSTFA), then analyzed by selected ion monitor of gas chromatography-mass speedtrometry (GC-MS). An 85 mum polyacrylate fiber can adsorb clenbuterol well. Extraction and derivatization conditions such as extraction time, temperature, pH, derivatization time, temperature, and the amount of derivatizing reagent have been optimized. The linear range for the analysis is 1 similar to 500 mug/L, with detection limits of 0.5 mug/L. The method has the advantages of quick operation and high sensitivity with the recovery of 82.0% similar to 87.7% and relative standard deviation of 3.9% - 6.8%.