基于Fe(III) 和邻苯二胺显色反应快速检测硫化物

Rapid detection of sulfide based on the chromogenic reaction of iron (III) ion and o-phenylenediamine

摘要:

比较了不同金属离子（Fe²⁺、Fe³⁺、Cu²⁺、Zn²⁺、Al³⁺、Na⁺、Ca²⁺、Mg²⁺、K⁺、Ag⁺、Cr³⁺）对邻苯二胺（OPD）的氧化能力，基于 Fe³⁺能直接氧化 OPD 产生黄色发荧光的产物而构建了 Fe³⁺-OPD 显色体系。结合硫化物的还原性以及对金属离子较强的亲和性，开发了一种通过比色法选择性检测硫化物的方法。结果表明，在 pH 4.0NaAc-HAc 缓冲液中，Fe³⁺-OPD 显色体系的吸光度和荧光强度与 NaHS 的浓度分别在 10~200 μmol/L 和5~150 μmol/L 范围内呈线性关系，荧光法的检出限可达 0.1 μmol/L，体系内其他还原性物质及硫醇对 NaHS 的检测无干扰。将 Fe³⁺-OPD 显色体系结合纸芯片构建的纸基比色体系蓝色分析色道值（B 值）与 NaHS 的浓度在20~150 μmol/L 范围内呈线性关系，检出限为 2 μmol/L，并可用于定量检测加标自来水和胎牛血清中的硫化物。关键词：Fe( Ⅲ )；邻苯二胺；硫化物；硫化氢；纸基比色法；功能材料

Abstract:

A Fe³⁺-OPD chromogenic system was developed based on the formation of yellow and fluorescent product from direct oxidation of OPD via Fe³⁺, which was selected from investigation on the oxidation ability of different metal ions (Fe²⁺, Fe³⁺, Cu²⁺, Zn²⁺, Al³⁺, Na⁺, Ca²⁺, Mg²⁺, K⁺, Ag⁺, Cr³⁺) towards o-phenylenediamine (OPD). A colorimetric method for selective detection of sulfide was then developed combining the reducibility of sulfide and its strong affinity towards metal ions. The results showed that, in NaAc-HAc buffer solution at pH 4.0, the absorbance and fluorescence intensity of Fe³⁺-OPD chromogenic system showed a good linear relationship with NaHS concentration ranging 10~ 200 μmol/L and 5~150 μmol/L, respectively. The fluorescence method exhibited a detection limit of 0.1 μmol/L with no observed interference from other reducing substances and thiols. The paper-based colorimetric system, constructed from Fe³⁺-OPD chromogenic system in combination with test paper, displayed a good linear relationship between blue color value (B value) and the concentration of NaHS in the range of 20~150 μmol/L, and a detection limit of 2 μmol/L. The paper-based colorimetric system was further applied for sulfide quantification in spiked tap water and fetal calf serum.