Improved gas chromatography-mass spectrometry method for the determination of clenbuterol and salbutamol in animal urine

An improved gas chromatography-mass spectrometry method, prepared for the confirmatory purposes, included solid phase extraction, derivatization, and analysis of clenbuterol and salbutamol derivatives. The whole procedure was validated in terms of linearity, decision limit detection capability precision, recovery, and uncertainty. The results of validation indicate that the prepared procedure is suitable for the confirmatory purposes. The decision limit for clenbuterol and salbutamol was established at the level of 0.022 ng/ml and 0.024 ng/ml, respectively, and the recoveries were about 70%.