罗丹明6G共振散射光谱法测定痕量铜(Ⅱ)

Determination of Trace Copper(Ⅱ)by Resonance Scattering Spectrometry with Rhodamine 6G

在盐酸溶液中,铜离子催化过硫酸钾氧化过量碘化钾生成I_(3)^(-),I_(3)^(-)与带正电荷的罗丹明6G形成缔合物微粒而产生共振散射效应,据此建立了检测痕量铜的共振散射光谱法。用单变量变换法优化测定条件,选择盐酸的浓度为3.33 mmol·L^(-1)、碘化钾浓度为1.5 mmol·L^(-1)、罗丹明6G浓度为6.33μmol·L^(-1)、过硫酸钾浓度为0.867 mmol·L^(-1),在30℃条件下反应15 min。在选定条件下,Cu^(2+)质量浓度在1.667×10^(-3)~0.020μg·mL^(-1)范围内,随着Cu^(2+)质量浓度的增大,体系在316 nm处的共振散射强度线性增强,其线性方程为ΔI=138.15+119524ρ,线性相关系数R^(2)为0.9889,检出限为7.53×10^(-4)μg·mL^(-1)。方法用于人发样和自来水中铜含量检测,检测结果的RSD为3.0%~4.1%,回收率为94.6%~97.3%。

In hydrochloric acid solution,copper ion catalyzes the oxidation of excess potassium iodide by potassium persulfate to produce I_(3)^(-),and I_(3)^(-) forms association particles with positively charged of rhodamine 6G to produce resonance scattering effect.Based on this,the detection of trace copper is established by resonance scattering spectroscopy.The measurement conditions were optimized by the univariate transformation method:the concentration of hydrochloric acid was 3.33 mmol·L^(-1),the concentration of potassium iodide was 1.5 mmol·L^(-1),the concentration of rhodamine 6G was 6.33μmol·L^(-1),and the concentration of potassium persulfate was 0.867 mmol·L^(-1),react for 15 min at 30℃.Under the selected conditions,the mass concentration of Cu^(2+)is in the range of 1.667×10^(-3)~0.020μg·mL^(-1).As the mass concentration of Cu^(2+)increases,the resonance scattering intensity of the system at 316 nm increases linearly,and the linear equation isΔI=138.15+119524ρ,the linear correlation coefficient R^(2) is 0.9889,and the detection limit is 7.53×10^(-4)μg·mL^(-1).The method was used to detect copper content in human hair samples and tap water.The RSD of the test results was 3.0%~4.1%,and the recovery rate was 94.6%~97.3%.