Development of new gas chromatography/mass spectrometry procedure for the determination of hexahydrophthalic anhydride in unsaturated polyester resins

This paper reports the first contribution to the determination of the hexahydrophthalic anhydride in unsaturated polyester resins by automated head space/solid-phase micro extraction and gas chromatography/mass spectrometry analysis. After a preliminary reaction of the acid anhydride with water to form carboxylic acids, a rapid on-sample derivatization using trimethyloxonium tetrafluoroborate was used. A new autosampler platform was proposed in this study by using the Multi Fiber Exchange device. The limits of detection for one mg of unsaturated polyester resin were 2.9 pg for the cis-1,2-cyclohexanedicarboxylic acid and 8.0 pg for trans-1,2-cyclohexanedicarboxylic acid, whereas the limits of quantification were 14.5 and 29.7 pg, respectively. The equilibrium and kinetics of this substance vs solid-phase microextraction are theoretically evaluated and discussed.