Ion-transfer stripping voltammetry and its application to trace analysis

利用选择性缔合的有机试剂，通过控制有机-水界面电位，可以将金属离子电化学萃取到有机溶剂中，当萃取溶剂体积很小时，可以限制在薄层内，电化学液/液萃取或简称电萃取，然后用薄层有机凝胶电极进行溶出伏安法，可测定ppb级的金属离子; Hg^2+和Pb^2+与1，4，7，10，13，16-六硫杂环十八烷的反应，Pb^2+、Cd^2+和Zn^2+与5，6-二苯基-3-（2-吡啶基）-1，2，4-三嗪的反应。同时，以Ca^2+为萃取剂，电萃取-溶出伏安法可测定水中10 ppb的烷基聚氧乙烯醚和烷基苯基聚氧乙烯醚表面活性剂，可用于痕量可电离药物的测定。本文详细研究了局部麻醉药普鲁卡因、利多卡因和抗组胺药多沙拉明、非那敏的伏安行为，并发现非挥发性溶剂1，6-二氯己烷可作为伏安法的萃取溶剂。

Metal ion can be extracted electrochemically into orgnic solvent by controlling the organic water interfacial potential with the aid of the organic reagent which selectively associates with the metal ion.When the extracting solvent volume is very small, which can be confined to a thin layer, the electrochemical liquid/liquid extraction or, in short, electroextraction, followed by stripping voltammetric techniques using the thin-layer organic gel electrode allows determination of metal ions at ppb levels; Hg^<2+> and Pb^<2+> ions with 1, 4, 7, 10, 13, 16-hexathiacyclooctadecane, and Pb^<2+>, Cd^<2+>, and Zn^<2+> ions with 5,6-dipenyl-3-(2-pyridyl)-1, 2, 4-triazine. Also, polyoxyethylene alkyl and alkyl phenyl ether surfactants in water at 10 ppb can be determined with Ca^<2+> ion as an extractant by the electroextraction followed by stripping voltammetry.The present voltammetric technique may be applied to the determination of ionizable drugs at trace level. Voltammetric behavior of the local anesthetics such as procaine and lidocaine and the antihistamine drugs such as doxlamine and pheniramine have been investigated in detail.Also, we found that a non-volatile solvent, 1, 6-dichlorohexane, is useful as the extracting solvent in the voltammetric technique.