【摘要】 在0.4mmol·L-1 B-R缓冲介质(pH 4.1)中,丁基罗丹明B(BRMB)被Fe(Ⅱ)与H2O2反应所产生的羟自由基迅速氧化而导致其产生的荧光强度明显减弱。当有己烯雌酚(DES)存在时,由于其对羟自由基有清除作用,而使上述反应体系的荧光减弱程度降低,即对BRMBFe(Ⅱ)-H2O2反应体系有抑制作用,而且反应体系的ΔF值(F-F0)与DES的质量浓度在0.1~50μg·L-1范围内呈线性关系。据此提出了测定DES的荧光光度法。反应体系的最佳条件如下:①BRMB的质量浓度:2.0mg·L-1;②硫酸亚铁的浓度:0.05mmol·L-1;③过氧化氢浓度:(φ)0.000 3%及④反应时间:6min。方法的检出限(3s/k)为0.045μg·L-1。以水样作基体,做加标回收试验,测得回收率在91.0%~106%之间,测定值的相对标准偏差(n=5)均小于5%。更多还原

【Abstract】 In 0.4 mmol·L-1 B-R buffer medium of pH 4.1,butyl-rhodamine B(BRMB)was rapidly oxidized by hydroxyl free radical produced by the reaction between Fe(Ⅱ)and H2O2,leading to significant decrease of fluorescence intensity of BRMB.When diethylstilbestrol(DES)was present in the above reaction system,due to the elimination action of DES toward OH free radical,the magnitude of decrease of fluorescence intensity was decreased,and values of fluorescence difference(ΔF=F-F0)were found to keep linear relationship with mass concentration of DES in the range of 0.1-50μg·L-1.Based on these facts,a method of fluorophotometric determination of DES was proposed.Optimum conditions for this reaction were found as follows:① mass concn.of BRMB:2.0mg·L-1;②concn.of FeSO4:0.05mmol·L-1;③concn.of H2O2:(φ)0.000 3%and④time of reaction:6min.Detection limit(3s/k)of the method was found to be 0.045μg·L-1.Test for recovery was made by standard addition method,giving results in the range of 91.0%-106%,with values of RSD′s(n=5)less than5%.更多还原