水中痕量铜的中性红-曙红Y同步荧光猝灭法检测

Determination of copper by synchronous fluorescence quenching method using eosine Y-neutral red

在pH8.5的Tris-HCl缓冲液中,曙红Y-中性红和Cu(Ⅱ)相互作用,在538nm处随着Cu(Ⅱ)浓度的增加,体系同步荧光强度逐渐降低,同步荧光强度降低值和Cu(Ⅱ)含量在一定范围内有相关关系。据此应用中性红-曙红Y同步荧光猝灭法建立一种测定铜的新方法。在优化的实验条件下,体系在538nm处的荧光强度降低值与铜的摩尔浓度在7.61×10-8-3.60×10-6 mol·L-1范围内线性关系良好,其线性回归方程为:△F=-0.414+314.89c(×10-6 mol·L-1),相关系数r=0.998,检出限为2.48×10-8 mol·L-1,相对标准偏差是0.26%,加标回收率是101.12%。本方法操作简便、灵敏、选择性好,可用于实际样品中铜的测定。

In the Tris‐HCl buffer solution of pH8.5 ,the system synchronous fluorescence intensity was obviously decreased with the increace of the concentration of Cu（Ⅱ ） at 538nm due to the interaction between the eosine Y‐neutral red complex and Cu（Ⅱ） ,and the decreased synchronous fluorescence inten‐sity was proportional to the concentration of Cu（Ⅱ） .Based on this phenomenon ,a novel method for the determination of copper was developed .Under the optimal experimental conditions ,there was a linear re‐lationship between the decreased synchronous fluorescence intensity and the concentration of the Copper at 538nm in the range of 7.61 ＆#215; 10-8‐3.60 ＆#215; 10-6 mol ＆#183; L -1 ,The linear regression equation was △ F= -0.414＋314.89c （ ＆#215; 10-6 mol ＆#183; L -1 ） with a correlation coefficient 0.998 ,and the detection limit was 2.48 ＆#215; 10-8 mol ＆#183; L -1 .The relative standard deviation was 0.26% ,and the average recovery was 101.12% . This method is simple ,sensitive and selective ,and has been used successfully in the determination of cop‐per in w ater samples .