二氧化氯-碘化物-吖啶红高灵敏显色反应及其分析应用

Highly Sensitive Chromogenic Reaction of Chlorine Dioxide-Iodide-Acridine Red and Its Analytical Application

在稀磷酸介质中 ,二氧化氯 ( Cl O2 )氧化 I- 形成 I3- ,I3- 进一步与吖啶红( ADR)阳离子形成离子缔合物 [ADR][I3]。在聚乙烯醇存在下 ,以试剂空白作参比 ,该离子缔合物的吸收波峰和波谷分别位于 5 82 nm和 5 2 6nm处 ,除波峰和波谷处吸光度与 Cl O2 的浓度有线性关系外 ,波峰和波谷的吸光度绝对值叠加也与 Cl O2 的吸光度呈直线关系。常规方法测定时 ,ε582 =1 .3× 1 0 5L· mol- 1· cm- 1;双波长法测定时 ,ε582 +52 6 =2 .9× 1 0 5L· mol- 1· cm- 1,对 Cl O2 的检出限分别为 0 .8μg/L和 0 .5μg/L。方法已成功地用于自来水中 Cl O2

A highly sensitive spectrophotometric method has been developed for the determination of trace amounts of ClO 2, based on the oxidation of I - to I 3 -by ClO 2 and the further reaction of I - 3 with acridine red to form the ion association complex in dilute phosphoric acid solution. In the presence of polyvinyl alcohol, the solution was transparent and a distinct color change occurred. λ max and λ min of the absorption spectrum were at 582 nm and 526 nm against reagent blank, respectively. It was found that besides the absorbances at λ max and λ min , the sums of the absolute values of λ max and λ min were also proportional to the ClO 2 concentration. The molar absorptivities were 1.3×10 5 L·mol -1 ·cm -1 for normal measurement at 582 nm and 2.9×10 5 L·mol -1 ·cm -1 for the dual wavelength measurement at 582 nm and 526 nm.In each case, the detection limits for ClO 2 were 0.8 μg/L and 0.5 μg/L. The method was successfully used for the determination of ClO 2 in tap water samples.