镉(Ⅱ)-碘化物-碱性呫吨染料体系的倍频散射和二级散射及其 分析应用

在稀磷酸介质中，当镉(Ⅱ)与过量Ⅰ^-离子形成CdI4]^2-配阴离子并进一步与罗丹明B(RhB)、罗丹明6G(Rh6G)、乙基罗丹明B(ERhB)和丁基罗丹明B(BRhB)等碱性呫吨染料(BXD)形成离子缔合配合物BXD]2CdI4]时，在产生强烈共振瑞利散射(RRS)的同时，也会产生强烈的倍频散射(FDS)和明显的二级散射(SOS)。在一定条件下散射强度与镉的浓度成正比。方法有高灵敏度和较好的选择性，可用于纯锌中痕量镉的测定。文中对于FDS和SOS产生的原因进行了初步的探讨。

Frequency doubling scattering and second-order scattering of cadmium (Ⅱ)-iodide-basic xanthene dye systems and their analytical applications

In dilute phosphoric acid solutions, cadmium (Ⅱ) reacts with excess of Ⅰ^- to form CdI4]^2- anionic complex, which may further react with basic xanthene dyes (BXD) such as rhodamine B(RhB), rhodamine 6G(Rh6G), ethylrhodamine B(ERhB), or butylrhodamine B (RhB) to form an ion-association complex of type BXD]2CdI4]. In this case, a strong frequency-doubling scattering (FDS) and significant second- order scattering (SOS) are produced. Under optimal conditions, the intensities of FDS and SOS are directly proportional to the concentration of cadmium. The method has high sensitivity and fair selectivity and can be applied to direct determination of trace amounts of cadmium in pure zinc. In this paper, the reasons for producing FDS and SOS are preliminarily discussed.