Analysis of Volatile Microconstituents in Daqu by HS-SPME and GC-MS

The volatile microconstituents in Daqu were studied by headspace solid phase microextraction(HS-SPME) coupled with GC-MS.The effects of sample concentration,ultrasonic extraction time,and different extracting solvent on the extraction of volatile microconstituents were also investigated.The results showed that the best extraction conditions were as follows: 0.2 g Daqu powder was dissolved in 5 mL deionized water,and then it was extracted by ultrasonic at 50 ℃ for 30 min,and finally the sample was detected by HS-SPME.Total of 112 volatile microconstituents were detected by GC-MS including 3 alkane,3 sulfide compounds,9 furans,6 aldehydes,8 esters,7 ketones,12 alcohols,21 aromatic compounds,23 pyrazines,11 acids,4 phenols,and 5 other heterocyclic compounds.The content of isopentanoic acid were highest and the second one was 2-phenylethanol.