共振光散射法测定环境水样中镉的研究及应用

The Research and Application of Determination of Cd^(2+) in Environmental Water by Resonance Light Scattering Method

在体积分数1%的OP介质中,Cd2+与S2-反应形成憎液溶胶体系,可使体系共振散射光强度增强.通过实验确定了适宜的反应条件及共振光散射强度与镉浓度之间的关系.在λ=476nm处,共振光散射强度最大,并且共振光散射强度与镉浓度成良好的线性关系,线性范围为0.0～20.0μg/mL,相关系数r=0.9995,检出限为6.33×10-3μg/mL,RSD为1.19%～1.42%,样品加标回收率为98.80%～102.30%.该方法简便、快速,用于实际样品中镉的含量测定,其精密度和灵敏度均优于紫外可见分光光度法,测量结果与原子吸收法相比较,令人满意.

In the presence of OP medium with 1% volume fraction, Cd^(2+) reacts with S^(2-) to form the hydrophobic sol, which makes the resonance light scattering(RLS) intensity of the system increase. The optimum reaction conditions and the quantitative relationships between the intensities of RLS and the concentration of Cd^(2+) are established. A RLS peak at 476 nm is found and its inlensity is directly proportional to the concentration of Cd^(2+) .The linear range is 0.0～20.0 μg/mL with the detection limit of 6.33×10^(-3) μg/mL for the Cd^(2+). The RSD and Recovery are 1.19%～(1.42%,)99.80%～102.30% respectively. The method is simple, rapid and sensitive. It has been applied to the determination of Cd^(2+) in environmental water samples. Its precision and sensibility are all better than that of ultraviolet-visible spectrometry and the results are satisfactory in contrast with atomic absorption method.