催化动力学分光光度法测定痕量铕

Catalytic Kinetic Spectrophotometic Determination of Trace Europium

摘要:

利用过氧化氢氧化丽春红褪色，以Eu3+为催化剂，建立一种新的测定铕的动力学分光光度法。在6.0×10-2 mol/L的盐酸介质中，Eu3+-H2O2-丽春红体系的最大吸收峰位于450 nm，Eu3+量在0~22 μg/25 mL范围内与吸光度差值△A呈良好的线性关系，其回归方程为△A = 0.0221 C + 0.0241 (C=μg/25 mL)，相关系数r = 0.9968，方法检出限为2.42 μg/L。本方法用于水样中铕的测定，13次测定相对标准偏差为0.49%~1.76%，加标回收率为95.20%~101.3%。

Abstract:

A new method for the determination of europium by kinetic spectrophotometry was established based on the catalytic effect of europium (III) on the fading reaction of ponceau with hydrogen peroxide. The maximum absorption peak of Eu3+- H2O2-Ponceau system is located at 450 nm in a 6.0×10-2 mol/L HCl medium. The absorbance difference (△A) is linearly related with the concentration of europium (III) in the range of 0-22 μg/25 mL, fitting the equation △A = 0.0221C+0.0241 (C = μg/25 mL ), with a regression coefficient of 0.9968. Detection limit of the method is 2.42 μg/L. The method was used to determine europium in environmental water samples. The relative standard deviation was 0.49%-1.76% for 13 replicated determinations. The recovery of the standard addition of the method was 95.20%-101.3%.