Simultaneous determination of acetoin and tetramethylpyrazine in traditional vinegars by HPLC method

A rapid and selective HPLC method was developed for the simultaneous analysis of acetoin (ACT) and tetramethylpyrazine (TMP). The chromatography was performed on a Zorbax SB-C18 column at 45 °C, with an aqueous mobile phase (1% acetic acid and 0.05% trifluoroacetic acid in water, pH 2.5)–(methanol) (45:55, v/v). The flow rate was 0.8 mL/min and UV detection wavelength was 297 nm. This method permits the simultaneous determination of ACT and TMP in fermentative foods with detection limits of 5.625 and 0.033 μg/mL, respectively. The recovery was 96.03% for ACT and 92.06% for TMP. Correlation coefficients were greater than 0.9999 for the two compounds. The linearity ranges for ACT and TMP were in the range of 0.02–20 mg/L and 0.12–80 μg/mL, respectively. The proposed method could be used for routine quality control of foods, beverages, natural products, or pharmaceuticals. Current data suggest that the content of TMP in vinegars is positively correlated with that of ACT.