催化荧光光度法测定痕量铜

荧光素（HFin）可发射强而稳定的荧光，Cu^2＋能氧化HFin而导致HFin的荧光信号猝灭．Cu（Bipy）^2＋（Bipy为α，a’-联吡啶）与4．0-D-Cu（4．0-D为4代聚酰胺-胺树枝状分子）能催化Cu^2＋氧化HFin的反应，使HFin荧光信号剧烈猝灭，且Cu^2＋的含量与AF值呈线性关系．基此实验事实，建立了Cu（Bipy）2＋和4．0-D—Cu（4．0代树枝状铜配合物）催化HFin荧光光度法测定痕量铜的新方法．该方法的线性范围为0．040～28（Pg mL^-1），工作曲线的回归方程AF=209．5＋14．39Ccu^2＋（Pg mL^-1），n=7，相关系数r=0．9991，检出限为1．0×10^-14g mL^-1．分别对0．040和28（Pg mL^-1）Cu^2＋重复测定8次，RSD依次为3．1％和4．2％．本方法快速、准确、灵敏、重现性好，并成功用于人发与茶叶中痕量铜的测定．同时探讨了Cu（Bipy）^2＋和4．0-D—Cu催化荧光光度法测定痕量铜的反应机理．

Catalytic Fluorescence Spectrophotometry for Determination of Trace Copper

Fluorescein can emit strong anti stable fluorescence, Cu^2＋ can oxdize fluorescein, which causes the fluorescence signal to diminish. Cu（Bipy）^2＋ （Bipy refers to α,α-dipyridyl） and 4.0-D-Cu （4.0-D refers to 4.0-generations polyamidoamine dendrimers） can both catalyze Cu^2＋ to oxdize fluorescein, which causes the lluorescence signal to diminish sharply. The AF is directly proportional to the content of copper. Thns, a new catalytic fluorescence spectrophotometry for the determination of trace copper using Cu（Bipy）^2＋ anti 4.0-D-Cu was established. The linear range of this method is 0.040-28 pg mL^-1. The regression equation for working curve is AF = 209.5 ＋ 14.39 C cu^2＋ （pg mL^-1）, n = 7, correlation coefficient is 0.9991. The detection limit of this method is 1.0 × 10^-14 g mL-I. For the systems containing 0.040 and 28 pg mL^-1 Cn^2＋ of the working solution, it was determined repeatedly for 6 times, respectively. The RSDs are 3.1% and 4.2%, respectively. This method is rapid and precise with high sensitivity and good repeatability. It has been applied to the determination of trace copper in tea and hnman hair with satisfactory results. Meanwhile, the mechanism for the determination of trace copper by catalytic fluorescence spectrophotometry using Cu（Bipy）^2＋ and 4.0-D-Cu was also discussed.