Application Progress of Headspace Gas Chromatography in Analytical Chemistry

This paper briefly expounds the basic principle and classification of headspace gas chromatography,summarizes its application in food analysis,environmental analysis and medical analysis,and forecasts the application prospect of headspace gas chromatography in analytical chemistry in the future.

The analysis of volatile flavor components of Jin Xiang garlic and Tai’an garlic

The volatile flavor compounds of Jin Xiang garlic and Tai’an garlic in chemical composition were detected and analyzed and the contents of them were compared and determinated. The volatile constituents of Jin Xiang garlic and Tai’an garlic were compared and analyzed by automatic static headspace and gas chromatography-mass spectrometry. Qualitative analysis of samples was made through the analysis of gas chromatography-mass spectrometry and NIST mass spectral library computer retrieval, and quantitative analysis was made by using area normalization method. The analysis results show that the slight difference of the volatile flavor compounds was detected in different places of origin garlic and Jin Xiang garlic was detected more total sulfur-containing compounds than Tai’an garlic. Meanwhile, the contents of sulfur compounds of the fresh garlic were more than the stored garlic and there were significant differences between them. The tests results indicated that flavor substances’ types were slightly different between Jin Xiang garlic and Tai’an garlic, and regional differences cannot affect the garlic flavor substances type. Jin Xiang garlic has more obvious flavor substances than Tai’an garlic which play a decisive role in the garlic flavor, such as 1,3-dithiane, and allyl trisulfide and allyl disulfide and diallyl tetrasulphide. The result of this research indicates that Automatic static headspace and gas chromatography-mass spectrometry is a fast, easy, efficient and accurate method to analyze and identify the volatile flavor components of garlic.

Characterization and discrimination of fermented sweet melon juice by different microbial strains via GC-IMS-based volatile profiling and chemometrics

The main purpose of this study was to investigate the effect of different lactic acid bacteria and yeast strains on the volatile composition of fermented sweet melon juice.Headspace gas chromatography-ion mobility spectrometry(HS-GC-IMS)coupled with chemometrics was performed to identify the potential volatiles for the discrimination of different fermented sweet melon juice.In total,70 volatile compounds were found in the fermented sweet melon juices.Of them,45 compounds were annotated according to the GC-IMS database and classified into esters,alcohols,aldehydes,ketones and furans.Results from the multivariate analysis reveal that sweet melon juice fermented by different combinations of microbial strains could be distinctly separated from each other.A total of 15 volatiles with both variable importance in projection value>1 and P<0.05 were determined as potential markers for the discrimination of fermented sweet melon juice.This study confirms the effect of microorganisms on the flavor of the fermented sweet melon juice and shows the potential of HS-GC-IMS combined with chemometrics as a powerful strategy to obtain volatile fingerprints of different fermented sweet melon juice.