Abstract:

A high performance liquid chromatographic (HPLC) method was established for the simultaneous determination
of organic acids in Yongchuan douchi, a Chinese traditional fermented soybean product. The optimal chromatographic
conditions were determined. An Agilent ZORBAX SB-Aq (4.6 mm × 250 mm, 5 μm) column was used to separate the
organic acids. The mobile phase was a mixture of 0.01 mol/L (NH4)2HPO4 (pH 2.5) and methanol solution at a flow rate of
0.6 mL/min. The column temperature and UV detection wavelength were set as 30 ℃ and 220 nm, respectively. The six
organic acids were successfully separated and determined under the chosen experimental conditions. The calibration curves
for all these organic acids displayed a good linear relationship with correlation coefficients above 0.999 9 and precision
relative standard deviations (RSDs) of 0.07%–0.36% (n = 5) and repeatability RSD of 0.97%–3.04% (n = 5). The recovery
rates of the six organic acids were in the range of 94.89%–104.28%. The method is convenient, rapid, accurate, reproducible
and applicable to determine organic acids in Yongchuan douchi.

Key words: Yongchuan douchi, high performance liquid chromatographic (HPLC), organic acid, determination