Application of Iron base mix-valence compounds in Electroanalytical chemistry

• Main Authors: Chen Pei Yan, 陳佩彥
• Other Authors: Zen Jyh-Myng
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/54011293985280295012

博士 === 國立中興大學 === 化學系 === 92 === Mixed-valence compounds especially prussian blue (PB) is one of the oldest complex in the inorganic chemistry. In this work we extensively used the PB and some hybrid PB type analogues for electroanalytical application. In the first part of thesis, we report a new electrochemical method for the selective detection of ultratrace amount of arsenite (AsO2-, AsIII) using a PB-modified screen-printed electrode (designated as PBSPE) by flow injection analysis (FIA). The Prussian yellow/PB redox couple of the PBSPE was found to mediate the AsIII oxidation. This modified electrode showed good resistance to interference from common ions, especially Cl-, which is generally considered as a major interference in the determination of AsIII by ICP-MS. Practical utility of the PBSPE was demonstrated to detect AsIII in “Blackfoot” disease endemic village ground waters from southwestern coast area of Taiwan (Pei-Men). Industrial waste cinder (CFe*) has been utilized as a stable anchoring matrix for the self-assembling of Fe(CN)63- as hybrid Prussian blue units (PB, *Fe3+FeII(CN)6) on a screen-printed carbon electrode for efficient catalytic applications in the second part of work. The waste cinder found to be a composite of calcium and iron silicates similar to glass matrix by XPS study. The hybrid PB formations were demonstrated using powder (using FT-IR) and the SPE modified cinder samples by chemical and electrochemical methods respectively. Most importantly, the free iron (Fe*) ion bound to the non-bridging oxygen terminals of the silicates found to be a key role in the PB formation. In next work we extend this electrode (Fe*-PBSPE) for the H2O2 determination by flow injection analysis (FIA) in presence a cationic surfactant; cetyl-trimethyl-ammonium-bromide (CTAB). In the third part, an amperometric FIA of ultratrace sulfide has been demonstrated on a screen-printed carbon electrode modified with industrially waste cinder/hexacyano cobaltate (CoHc) hybrid (designated as cinder/CoHcSPE). Possible mediated electrocatalytic oxidation is explained in terms of higher oxidation state of Co in the hybrid-bimetallic complex. In the last part, we studied a basic surface feature of a smooth carbon (glassy carbon) by investigation with ascorbic acid (AA) model oxidation reaction in presence of allopurinol quencher. The studies will help to construct a stable PB modified film on rough SPE surface. In further, enzymeless AP detection assays was demonstrated through its inhibitory signal by taking AA in the mobile phase in FIA.