Gas chromatography-mass spectrometric analysis of clenbuterol from urine.

Clenbuterol which is mostly used as an anabolic agent. It is also used for treatment of asthma. Clenbuterol was analysed from urine by using gas chromatography-mass spectrometry. GC-MS parameters were determined. Timolol was used as an internal standard. Extraction and derivatisation procedure of clenbuterol from urine were developed. Clenbuterol was extracted by using diethylether/ter-butanol (4:1; v:v) and pH 12 K2CO3/KHCO3 (3:2; w:w) buffer. MSTFA/NH4I (1 ml/10 mg) mixture was used for derivatization of clenbuterol. Selected ions of clenbuterol-bis-TMS were m/z: 405, 337, 336, 335, 300, and 227. Extraction yield and minimum detection limit of clenbuterol from urine were identified. Extraction yield was 94.30% and minimum detection was found 0.02 ng ml(-1) urine. It has been concluded that the GC-MS method is sensitive, accurate, precise, and reproducible for analysing of clenbuterol from urine.