Study On Synthesis Of New Phenylfluorone Reagents And Their Application In Food Analysis

Microelements have very important function in life science, it influence on our health seriously. Because phenylfluorone reagent can react with many metal ions sensitively and may be widely applied to determine microelement in foods . However, the phenylfluorone reagents in literatures exist a lot of disadvantage and require strongly to synthesize new derivatives of phenylfluorone. In the paper, the synthesis method of new phenylfluorone reagent, color reaction of the reagents with metal ions, the application to determination of microelements in foods and related mechanism problems were studied in detail, respectively. Main text were listed in following:Seven new reagents including trimethoxyphenylfluorone, dihydroxyphenylfluorone, trihydroxy-phenylfluorone, 2' -hydroxyl-3' -methoxyphenylfluorone, 2' -hydroxyl-4' -N,N-diethyphenylfiuorone, p-carboxyphenylfluorone and 3',5'-di-bromo-4'-hydroxyphenyl-4,5-dibromofluorone have been designed and synthesized; Traditional synthesis method were revised, this result in increasingproductivity of the above compounds obviously; The structure and elemental constitution of/ p-carboxyphenylfluorone, trimethoxyphenylfluorone, 2'-hydroxyl-3'-methoxyphenylfluorone anddibromohydroxyphenylfluorone were confirmed by element analysis, ultraviolet spectrum (UV), infrared spectrum (IR), :H-NMR, 13C-NMR and EIS-MS, respectively.The heating stability of the reagents were also studied by DSC analysis. It can be seen clearly a high endothermic peak, which was produced by reagent's melting, the melting point of the reagent obtained by DSC was almost same as that of method using melting point determination instrument; The dissociation constants of the reagents in water were determined and calculated by spectrophotometry and Klygin's formula. Moreover, we also studied on the electronic charge distributing and optimal conformation of reagent molecular by quantum mechanics calculation. Basing on the electronic charge distributing of the reagent we requested a suit dissociation procedure.In the work, optimal reaction conditions and analytical characteristics of corresponding complex which were formed by p-carboxyphenylfluorone, trimethoxyphenylfluorone, 2'-hydroxyl-3'-methoxy-phenylfluorone and dibromohydroxyphenylfluorone with molybdenum(VI),iron(III),uranium(VI), aluminum(III), tin(IV),germanium(IV) and tungsten(VI), respectively. Basing on above reaction, we developed a series of new spectrophotometric or fluorescent methods for determination of various trace elements in food or biological samples. These methods were listed in following. Spectrophotometric determination of trace molybdenum in food and plant samples with new reagent p-carboxyphenylfluorone;Spectrophotometric determination of trace molybdenum in microorganism cytoplasm with p-carboxyphenylfiuorone; Spectrophotometric determination of trace iron in biological samples with p-carboxyphenylfluorone; Spectrophotometric determination of ferbam in commercial samples; Spectrophotometric determination of uranium(VI) in water with p-carboxyphenylfluorone; Spectrophotometric determination of trace germanium in foods with trirnethoxyphenylfluorone; Spectrophotometric determination of aluminum in foods with new 2'-hydroxyl-3'-methoxy- phenylfluorone; Spectrophotometric determination of tin in foods with 2'-hydroxyl-3'-methoxy- phenylfluorone and Fluorescence quenching method for determining combination of blood plasma protein and tungsten(IV) using dibromohydroxyphenylfluorone as an emission reagent. Comparing with previous methods, proposed methods' analytical characteristics have been improved obviously such as sensitivity and selectivity and has been applied to analysis real samples.In this work, a new mechanism model for synthesis of phenylfluorone compounds was developed. We suggested total procedure are including five steps, and the reaction of aromatic aldehyde with H2S04 is most important to total reaction rate; we calculated the electron density of each atom in molecular formula of phenylfluorone reagent by quantum...