Use of Stir Bar Sorptive Extraction and Thermal Desorption for Gas Chromatography-Mass Spectrometry Characterization of Selected Volatile Compounds in Chinese Liquors

Stir bar sorptive extraction and thermal desorption system followed by gas chromatography-mass spectrometry (SBSE-TDS/GC-MS) have been applied to the characterization of selected volatile compounds of Chinese liquors. Calibration curves were achieved for quantification with correlation coefficients ranging from 0.9875 to 0.9996. Limits of detection (LODs) and limits of quantification (LOQs) were obtained ranging from 0.007 to 17.89 μg L−1 and from 0.02 to 69.6 μg L−1, respectively. Repeatability was between 0.2 and 7.0 % while intermediate precision was between 0.1 and 7.5 %. Afterward, five Chinese liquors having different flavor types were investigated using the SBSE-TDS/GC-MS method. A total of 87 volatile compounds, including 40 esters, 12 alcohols, 8 acids, 2 phenols, 8 aldehydes and ketones, 7 acetals, 6 furans, 1 sulfuric compound, and 3 pyrazines, were identified and quantified. The obtained results of GC-MS were then subjected to analysis of variance (one-way ANOVA) followed by partial least squares regression (PLSR). ANOVA results indicated that 52 components (p ≤ 0.05) were useful in characterizing the five liquor aromas. It showed that the ANOVA-PLSR model could well elucidate the correlation between liquors and the identified volatile compounds and could well indicate the possibility to discriminate sauce-flavor and strong-flavor liquors.