Simultaneous determination of terbutaline and salbutamol in plasma by selected ion monitoring.

We describe a method for simultaneous determination of terbutaline and salbutamol in plasma, based on gas chromatography chemical ionization mass spectrometry. Deuterium labelled terbutaline was used as internal standard for both drugs. The method has been used for the analysis of plasma samples obtained from asthmatic patients. The coefficient of variation at 0.3 ng ml-1 was 4.6% for terbutaline and 5.3% for salbutamol with a sample volume of 4 ml. The recovery of both drugs was greater than 80%.