直接电位滴定法测定葡萄糖氧化酶活度OACSTPCD

A new method for the potentiometric titration determination of glucose oxidase activity in flour additives was established.Glucose oxidase catalyzes the oxidation of glucose to produce H2O2,Cerium(IV)ion(Ce4+)undergone a 2∶1 quantitative reaction with H2O2,where when titrating H2O2 with a standard Ce4+solution,the amount of H2O2 generated directly reflected the glucose oxidase activity.The titration conditions were investigated,and the accuracy and precision of the method were systematically analyzed.The results showed that the glucose oxidase activity in the range of 0.00 to 3.40 U/mL was linearly related to the titration volume of the standard Ce4+solution:∆V(Ce4+)=6.061X(U/mL)-0.0223,with a correlation coefficient of 0.9988.The method's limit of detection was 4.94×10-3 U/mL.Using a self-prepared glucose oxidase working solution as the test solution,six parallel measurements were conducted with a relative standard deviation(RSD)of less than 5%.