Quantitative determination of trimetoquinol in plasma as its mixed pentafluoropropionyl-trimethylsilyl derivative by gas chromatography mass spectrometry.

A method is described for the determination of the bronchodilator trimetoquinol in plasma, based on selected ion monitoring gas chromatography mass spectrometry employing a deuterated trimetoquinol as internal standard. N-methyl-(trimethylsilyl)pentafluoropropionamide and N-methyl-bis-pentafluoropropionamide were prepared for derivatization of trimetoquinol into a mixed O-TMS-N-PFP derivative, which was found to be the most suitable form in terms of sensitivity, specificity and efficiency. The calibration curve was linear in the range of 2-50 ng ml-1, and the lower limit of detection was 0.1 ng ml-1 of rat plasma.