Determination of organic acids change in the process of Tianjin Duliu ageing vinegar with HPLC

An effective method with HPLC, which is adapt to detect organic acids in complex matrix on the basis of laboratory, was developed and improved. By the use of Aminex HPX-87H ion-exclusion column, the optimum separation conditions are as follows: 0.005 mol/L H2SO4 as mobile phase, flow rate at 0.6 ml/min, column temperature at 30℃, UV detector at 215 nm, and sample volume as 20 μl. The RSD is 0.04～3.42%, and the recovery rate is 81.8～90.3%. The method is used to detect the changes of organic acids in different years Duliu aging vinegar. The content of malic acid and latic acid are high in all samples, malic acid and lactic acid increase progressively with aging time, however, acetic acid reduces. Contents of oxalic acid and tartaric acid are low. And no changes of oxalic acid and tartaric acid occurred in aging time.