Optimization of Headspace Solid Phase Microextraction Conditions for G-C-MS Analysis of Aromatic Constituents in White Liquor
Headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled with mass spectrometry (GC-MS) were used for the qualitative determination of volatile compounds in white liquor samples. HS-SPME experimental conditions, such as sample volume in headspace glass vial, ionic strength, equilibrium temperature and time, desorption time were optimized The best extraction performance was achieved under the following conditions: 40% sample volume is headspace glass vial with addition of 0.2 g/mL NaCl, 30 min equilibrium time at 50 ℃ with stirring speed of 200 r/min, 30 min headspace adsorption time, and 15 min desorption time in the GC inlet at 250 ℃. As a result, 42 aroma compounds were extracted out of the tested liquor sample (from Songhe Liquor Industry Co. Ltd.), including 26 esters, 6 fatty acids, 5 higher alcohols, 2 aldehydes, 2 ethers and 1 anhydride.