基于铍试剂Ⅲ二阶导数极谱法测定壳聚糖含量

Based on Beryllon Ⅲ Second Derivative Polarographic Determination of Content of Chitosan

在pH 3.5的六次甲基四胺-盐酸缓冲溶液中,铍试剂Ⅲ在峰电位-0.318V(vs.SCE)处能产生一灵敏尖锐的二阶导数极谱波,当在体系中加入一定量的壳聚糖时,该二阶导数极谱波峰电流会降低,在选定的最佳条件下,其峰电流的降低值与加入的壳聚糖的质量浓度在0.5～6mg/L的范围内呈线性关系,线性回归方程为Δip=-4.06+84.89c,相关系数r=0.997 1,检出限0.4mg/L。

Beryllon Ⅲ can react with chitosan to produce an electrochemically inactive complex of Beryllon Ⅲ-chitosan in the buffer solution of (CH2)6N4(pH=3.5).Beryllon Ⅲ has a well-defined second derivative polarographic wave at peak potential-0.318 V(vs.SCE).Adding chitosan into the Beryllon Ⅲ solution would result in the decrease of peak current without the change of peak potential.The decrease of peak current is proportional to the concentration of chitosan from 0.5 to 6 mg/L(r=0.997 1)and the linear regression equation is Δip=-4.06+84.89 c.The detection limit is 0.4 mg/L.