科研之友
微信
新浪微博
Facebook
分享链接
摘要
A formula of E-c = k Delta A/Delta t was proposed for determining the activity concentration (E-c) of the enzymes based on a flow. injection spectrophotometric system (FI-SP). In the formula, Delta t was the mean residence time of the sample plug injected in the system and it was in a linear response region of the enzymatic reaction, Delta A was a response peak at the residence time, and k = nV/(Delta vL), in which, V was the total volume of the connecting pipeline from an injected sample point to a entrance of a flow. cell, n was the reaction molar ratio of enzyme substrate and product, epsilon was a molar absorption coefficient of the product, v was an injection volume of enzyme solution, L was optical path length of the flow. cell, and k became a constant when the FI-SP system was defined. On this basis, by introducing the reaction of H2O2/peroxidase (POD)/guaiacol (GA) into the FI. SP system, a new method for rapid and accurate determination of the POD activity was established without the standard curve. The optimized conditions for this method were as follows: the concentration of phosphate buffer used as the carrier was 0.05 mol/L (pH 5.5), the sampling volume was 40 mu L, the reaction coil length was 200 cm, the H2O2 concentration was 1.5 mmol/L, the GA concentration was 3.5 mmol/L, HCl used as a cleaning fluid was 0.4 mol/L, the detection wavelength was 470 nm, and the product. s molar absorption coefficient was 0.0125 L (mol cm)(-1). The RSD of the method was 0.38% (n = 11), the analytical rate was 40 samples/h, the determination range was 450-7260 U/L, the detection limit was 7.0 U/L. Under the optimum conditions and at 60 degrees C, the POD activity in different radishes was determined by this method, and the results obtained here were the same as the results obtained by kinetic curve method.
- 出版日期2015-10
- 单位四川大学
