Microwave-assisted derivatization of volatile carbonyl compounds with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine

A method for the determination of carbonyl compounds, either directly from gaseous phase or following a volatilization from liquid or solid samples after trapping on Tenax TA is presented. Following solvent desorption, the carbonyls are derivatized using O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine. The reaction is accomplished in a microwave oven using closed vessels to minimize reaction time compared to conventional methodology. The solvent for the chemical reaction was selected according to the requirements of microwave energy interaction and solubility. After gas chromatographic separation of the corresponding oximes, they are detected using electron impact mass spectrometry in single ion monitoring mode. Quantification is carried out using internal standardization with 3-fluorobenzaldehyde, resulting in limits of detection in the ppm range following the calibration graph method. The optimized conditions provide for good recoveries and fast reaction rates for the volatile carbonyls studied so far.