Development of novel catalytic methods of analysis for trace characterization

为了获得有关环境中痕量元素的数量、存在状态、分布和循环的信息，仍然需要灵敏和选择性的分析方法。基于催化反应的动力学分析方法因其极高的灵敏度、低的检测限和选择性而被用于各种元素的痕量分析。用催化动力学分析方法，可以很容易地测定低至10^&lt；-9&gt；-10^&lt；-11&gt；M的金属离子。将流动注射分析(FIA)与催化方法相结合，具有精密度高、样品处理速度快等优点。为此，我们建立了流动注射分析铁(II、III)、钴(II)、铜(II)、钒(IV、V)和亚硝酸根离子的动力学催化方法。本工作中使用的指示反应如下：a)3-甲基-2-苯并噻唑肼(MBTH)与N，N-二甲基苯胺(DMA)的氧化偶联反应和/或对Fe(II，III)和/或Co(II)的Trin der试剂的修饰；b)N-苯基-对苯二胺与DMA对铜(II)和/或间苯二胺的氧化偶联反应；(C)3，3‘，5，5’-四甲基联苯胺(TMBZ)的过氧化氢氧化生成Fe(II，III)；d)N-3-磺丙基-TMBZ的溴酸盐氧化生成V(TV，V)；e)MBTH的过氧化氢氧化生成Fe(II，III)；f)在phen存在下，Fe(III)与半胱氨酸发生氧化还原反应。进一步提高动力学催化法灵敏度的可能性之一是使用活化剂。对Fe(II，III)，V(IV，V)和Co(IJ)的催化作用，邻菲咯啉、磺基硫氰酸盐和TIron分别是有效的活化剂。这些方法已成功地用于天然水样和标准物质的测定。

In order to obtain the information on the amount, existing state, distribution, and circulation of trace elements in environment, the sensitive and selective methods of analysis are still desired. Kinetic methods of analysis based on catalytic reactions have been utilized to trace analysis for various elements because of their extremely high sensitivity, low limit of detection and selectivity. By using the catalytic-kinetic methods of analysis, as little as 10^<-9> - 10^<-11> M of metal ions can easily be determined. The adaptation of flow injection analysis (FIA) to catalytic methods can lead to many advantages such as higher precision and rapid sample throughput. We thus developed the kinetic-catalytic methods of analysis for iron(II, III), cobalt(II), copper(II), vanadium(IV, V) and nitrite ions by FIA methods. Indicator reactions used in this work are as follows : a) Oxitative coupling reaction of 3-methyl-2-benzothiazolinone hydrazone (MBTH) with N,N-dimethylaniline (DMA) and/or modifies Trinder's reagent for Fe(II,III) and/or for Co(II), b) Oxidative coupling reaction of N-phenyl-p-phenylenediamine with DMA for Cu(II) and/or m-phenylenediamine for NO_<2->, c) Hydrogen peroxide oxidation of 3,3', 5,5'-tetramethylbenzidine (TMBZ) for Fe(II, III), d) Bromate oxidation of N-3-sulfopropyl-TMBZ for V(TV, V), e) Hydrogen peroxide oxidation of MBTH for Fe(II,III) and f) Redox reaction of iron(III) with cysteine in the presence of phen for Cu(ll). One of the possibilites for further increasing the sensitivity of the kinetic-catalytic methods is the application of activators. Phen, sulfosulycylate and Tiron acted as effective activators for the catalysis of Fe(II, III), V(IV,V) and Co(IJ), respectively. These methods have been successfully applied to the determination of natural water samples and reference materials.