Abstract: Tetramethylpyrazine, 4-methyl guaiacol and 4-ethyl guaiacol in 67 Chinese Baijiu samples were detected by vortex assisted liquid-liquid microextration (VALLME) combined with gas chromatography-mass spectrometry (GC-MS). The analytes were extracted with CH2Cl2, using a vortex agitator for 1?min, and then centrifuged at 6 000?r/min for 5?min. After that, the CH2Cl2 phase was directly injected into GC-MS for analysis. The results indicated that the calibration curves for the three analytes displayed a good linearity (R2 > 0.99) in the ranges of 0.5–2 500, 1.0–2 500, and 1.0–2 500?μg/L, respectively. The limits of detection (LODs) for tetramethylpyrazine, 4-methylguaiacol and 4-ethyl guaiacol were 0.25, 0.5 and 0.5?μg/L, respectively. The recoveries were in the range of 80.1%–88.0%. The method was successfully employed to detect the analytes in 67? Chinese Baijiu samples and the results showed that all the samples contained 1.5–2 434.3?μg/L tetramethylpyrazine, of which 51 contained 2.8–1 709.0?μg/L 4-methylguaiacol, and 53 contained 1.3–1 167.5?μg/L 4-ethyl guaiacol. The differences in the contents of the health-beneficial ingredients in Chinese Baijiu may be related to the raw materials and manufacturing process.

Key words: Baijiu, tetramethylpyrazine, 4-methyl guaiacol, 4-ethyl guaiacol, vortex assisted liquid-liquid microextration (VALLME)