Rapid extraction of clenbuterol from human and calf urine using Empore C8 extraction disks

In the present paper, disk extraction was evaluated for the rapid isolation of clenbuterol from human and calf urine, followed by high-performance liquid chromatography analysis with UV detection. A method was developed for the extraction with standard density C8 disks. The disks could be washed with 25% methanol in 0.01M sodium hydroxide without significant losses of clenbuterol. The recovery of clenbuterol was about 85%, and the extracts were clean. The detection limit was about 10 ng/mL. The main advantages of these disks were the saving of time and the reduced amounts of organic solvents needed.