Determination of Lactic Acid in Fermentation Broth of Rhizopus Oryzae by Reversed-Phase High Performance Liquid Chromatography (RP-HPLC)
反相高效液相色谱法测定米根霉乳酸发酵液中的乳酸

A method for determining lactic acid in fermentation broth of Rhizopus oryzae by RP-HPLC is described. The operating conditions were Wakosil-II 5 C18 RS column(4.6 mm i.d. x 150 mm, 5 microns) at room temperature, 0.01 mol/L phosphoric acid solution (pH 2.5) as mobile phase with a flow rate of 1.0 mL/min and UV detection at 210 nm. The retention time of lactic acid was 3.820 min. This method is simple, rapid and accurate. The results will not be affected by other components in the broth. The relative standard deviation was 0.22% (n = 5), and the recovery was over 99%.