8-羟基喹啉-5-磺酸共振光散射法测定铅

Resonance light scattering detection of Pb^(2+) using 8-hydroxyquinoline-5-sulphonic acid

在pH 5.0 BR缓冲液及阳离子表面活性剂CTMAB存在下,8-羟基喹啉-5-磺酸与Pb2+相互作用形成配合物,导致体系的共振光散射(RLS)强度增强,且在8.01×10-8～1.2×10-5mol/L范围内,体系ΔI强度与Pb2+的浓度有良好的线性关系,其回归方程为:ΔF=–91.23+61.21c(×10-6mol/L),相关系数r=0.997 6,检出限为2.40×10-8mol/L,相对标准偏差(RSD)在2.15%～4.01%。用于环境中水样的测定,回收率在96.3%～99.6%。该方法简单、快速、灵敏度高。

In the Britton-Robinson buffer solution of pH 5.0,8-hydroxyquinoline-5-sulphonic acid may re- act with Pb2＋ to form a binary complex of HQS-Pb2 ＋ in the presence of cationic surfactant CTMAB, resul- ting in the enhancement of resonance light scattering （RLS） intensity. 2d is directly proportional to the concentration of Pb2＋ in the range of 8.01×10 -s-1.2×10 -5 mol/L. The equation of linear regression is △F = - 91.23 ＋ 61.21c（ ×10-6 mol/L） with a correlation coefficient （r） of 0. 997 6. The detection limit （LOD） is 2.40×10-8 mol/L,the relative standard deviations were 2.15% - 4.01%. And the re- covery was 96.3% -99.6%. The proposed method was simple,rapid and sensitive