Determination of lactic acid and acetic acid content in biological selenium vinegar and vinegar by HPLC method

Determination of lactic acid and acetic acid of biological selenium vinegar and vinegar by using HPLC method were studied.C₁₈ as chromatographic analysis column, detection wavelength was 215 nm, the mobile phase was 2.5% NH4H2PO4 buffer, sample dilution was 30 times, the flow rate was 1.0 min/m L, the column temperature was 29 ℃, the best p H of the biological selenium vinegar was 2.5, while the best p H of the vinegar was 2.7, which could better separation and determination of lactic acid and acetic acid of biological selenium vinegar and vinegar, all testing completed within 4 min.When other analysis conditions were certain, p H was 2.5, the regression equation of acetic acid and lactic acid standard were y = 484.23x-81.373, R²= 0.9992, y = 441.37x-68.321, R²= 0.9979, respectively.When p H was 2.5, the regression equations of acetic acid and lactic acid standard were y = 484.61 x + 72.201, R²= 0.9993, y = 389.82 x + 30.432, R²= 0.9991, respectively. The relative standard deviation of this method was 0.00% ¹.07%, standard addition recoveries of biological selenium vinegar lactic acid and acetic acid standard were 100.00% ¹10.00%, 99.00% ¹00.83% respectively, standard addition recoveries of vinegar lactic acid and acetic acid were 100.00% ~ 101.00%, 100.00% ~ 110.00% respectively. The method has good repeatability, accuracy and precision, short detection time, therefore it could be applied in biological selenium vinegar and vinegar.