Abstract: Totally nine volatile trace components in 20 samples of different kinds of Chinese Baijiu were analyzed by liquid-liquid extraction (LLE) combined with gas chromatography-mass spectrometry-selective ion monitoring (GC-MS-SIM). The average recoveries of the developed method were in the range of 81.80%–109.30%, with a precision (relative standard deviation, RSD) of less than 6.00%. Excellent linearity was observed in the tested concentration range (R2 > 0.999 0). The limit of detection (LOD) and the limit of quantification (LOQ) were 0.17–0.91 and 0.58–3.04 μg/L, respectively. The results showed that among the nine functional compounds, three terpenes had higher concentrations in Nongxiangxing Baijiu, and their concentrations in the Baijiu samples from a producer in Chengde, Hebei were higher than those in other samples examined. Four phenolic compounds had the highest concentrations in Zhima-flavor Baijiu, and the total amount of phenolics was 4 301.61 μg/L in sample W09. The concentration of tetramethylpyrazine in Jiang-flavor Baijiu was 2 379.65–2 985.09 μg/L, much higher than that in Zhima-flavor Baijiu (1 116.80–1 309.66 μg/L) and Nongxiangxing Baijiu (245.40–555.76 μg/L). The concentration of linoleic acid ethyl ester significantly varied in the range of 1 951.96–7 183.35 μg/L among different samples expect for W17, W19 and W20.

Key words: Chinese Baijiu; trace functional compounds; liquid-liquid extraction; gas chromatography-mass spectrometry-selective ion monitoring