Ionic Liquids as Advantageous Solvents for Headspace Gas Chromatography of Compounds with Low Vapor Pressure

The potential of ionic liquids as solvents for headspace
gas chromatography was investigated. Three compounds
with boiling points above 200 °C were selected to demonstrate the feasibility of the concept described. 2-Ethylhexanoic acid, formamide, and tri-n-butylamine as examples of acidic, neutral, and basic analytes were dissolved
in acidic 1-n-butyl-3-methylimidazolium hydrogen sulfate
(1), neutral 1-n-butyl-2,3-dimethylimidazolium dicyanamide (2), and 2 containing 1,8-diazabicyclo[5.4.0]undec-7-ene to adjust basic conditions. All analytes could be
determined with limits of detection and limits of quantification in the low-ppm concentration range.