荷移光度法测定山药尿囊素的含量

Spectrophotometric Determination of Allantoin in Rhizoma Dioscoreae Based on Charge-Transfer Reaction with Tetrachlorobenzoquinone

采用四氯对苯醌与尿囊素进行荷移反应测定尿囊素。建立了荷移光度法测定方法的条件是四氯对苯醌与尿囊素在硼酸钠与氢氧化钠为酸度调节液中，温度30℃反应15—100min后可获得1：2稳定的荷移络合物，其可见光区的λmax=558nm，尿囊素的线性方程为A=7．185×10^5c-0．0003（r=0．998），表观摩尔吸光系数ε=7．856×10^5L／（mol·cm），最低检测限为1．6μg／mL，尿囊素的浓度在0～4．0×10^-4mol／L范围内遵从比尔定律。通过对市售的几种山药实样的测定，其结果与用薄层层析-紫外可见分光光度法的测定结果一致，回收率为98．8％～104％，RSD为1．3％～2．0％。结果表明此方法操作简便，灵敏度高，结果较为满意。

A new spectmphotometric method for determination of allantoin was developed based on a 1：2 charge transfer complex of tetrachlorobenzoquinone in borax buffer solution with the apparent molar absorptivity of 7. 856 × 10^5 L/ （mol·cm） and the minimum detectability of 1.6μg/mL at 558 um. Beer＇s law is obeyed in the range of 0-4.0× 10^-4 mol/L with the relative standard deviation of 1.3 % -2.0% and the recovery of 98.8% - 104%. This method was successftdly applied to the determination of allantoin content in Rhizoma Dioscoreae, Results show that this method is simple, fast and accurate; it is applicable for the detection of allantoin in Rhizoma Dioscoreae.