【作者】 董瑞；

【导师】 胡荣宗；

【作者基本信息】 厦门大学 ， 分析化学， 2007， 硕士

【摘要】 论文依据电化学原理研究了三种用于离子色谱法的前处理方法与相关装置:在采用离子色谱法检测玉米中的钠、铵、钾、镁、钙时采用电解水产生OH-的方法中和了样品消解液的酸度使之适合离子色谱法分析;在采用离子色谱法检测紫菜中的含碘量时采用电化学氧化将样品中的碘全部转化为IO3-,使之可以采用通用、灵敏的抑制电导离子色谱法进行检测;在采用离子色谱法检测面粉中的溴酸根离子时采用电化学方法将被测离子由BrO3-转化为Br-,克服了样品中大量Cl-对测定的干扰。论文中的电化学前处理装置为由离子交换膜及耐蚀电极组成的电渗析槽或电解槽。本论文共分四章。第一章综述了离子色谱法测定样品的各种前处理方法,介绍了电化学前处理器的原理及相关知识。根据传统前处理方法的局限性、离子色谱测定对测定样品的要求以及电化学前处理的优点提出电化学前处理装置应用于离子色谱法的优点。第二章主要研究了电化学酸中和前处理方法及其在检测玉米中钠、铵、钾、钙、镁等5种常见阳离子时的应用。本章主要分为四节:第一节介绍检测玉米中钠、铵、钾、镁、钙的意义和已有检测方法的不足,并提出将电化学中和器应用到离子色谱法前处理中。第二节介绍了消解、电化学中和前处理的具体操作步骤。第三节讨论实验结果和实验条件。讨论了电化学中和的必要性和可行性,电化学中和器的结构和工作流程,以及不同样品、不同检测方法的测定结果。第四节小结。第三章研究了电化学氧化前处理方法及其在检测紫菜中碘时的应用。分为四节:第一节叙述了测定紫菜等食品中碘含量的意义,现有的检测方法及这些方法的不足之处,提出了电化学氧化离子色谱法测定紫菜中碘的新方法。第二节介绍了电化学氧化离子色谱法测定紫菜中碘含量的实验条件和实验步骤。第三节讨论了实验结果和实验条件。讨论了采用电化学氧化的原因,分析了电化学氧化的可能性及所需条件,讨论了电化学还原装置的结构、工作流程,实验条件的选择及同光度法的比较。第四节小结。第四章研究了电化学还原前处理方法并将其应用到检测面粉中的溴。本章分为四节:第一节介绍了面粉中溴酸盐问题的由来,已有的各种检测方法及各种方法的不足之处。第二节介绍了电化学还原离子色谱法测定面粉中溴酸盐的实验条件及具体实验步骤。第三节讨论了实验结果、实验条件。讨论了电化学还原装置的结构、工作流程,分离及电化学还原的条件。第四节小结。更多还原

【Abstract】 In the dissertation ,3 kinds of electrochemical pretreatments and homologous equipment used in ion chromatography(IC) were studied . When determining Na+,NH4+、K+、Mg2+ and Ca2+ in cron, OH- was produced by electrolyzing water to neutrolize the acid in sample,so the sample was suitble for ion chromatography. When determining Iodine in laver ,I- was exchanged to IO3- by electrochemical oxidizer , then Iodine could be determined by suppressed conductance ion chromatography. When determining bromate in flour,BrO3- was exchanged to Br- by electrochemical reductor,then the interference with determination of BrO3- by ion chromatography from Cl- was eleminated. The electrochemical pretreatmentor were electrodialysis cell or electrolytic bath made of anion exchange membrane and electrodes that plated platinum on titanium.There are four chapters in the dissertation.In chapter 1, the pretreatments of ion chromatography,principle and related knowledges of electrochemical pre-processor were introduced. An electrochemical pretreater of IC was proposed .In chapter 2,an electrochemical neutralization and its application to determining Na+,NH4+,K+,Mg2+,Ca2+ in corn were studied. This chapter was divided into four sections:In section 1, the significance of determining Na+,NH4+,K+,Mg2+,Ca2+ in corn ,disadvantages of traditional determinations,introduced . Using electrochemical nutrilization as pretreatment of IC was proposedIn section 2 , the digestion and the electrochemical nutrilization were introduced.In section 3, the experimental result and experimental condition were discussed.In section 4 ,the brief summary was made. In chapter 3,an electrochemical oxidation and its application to determining iodine in laver were studied. This chapter was divided into four sections:In section 1 ,the significance of determining iodine in laver and shortages of the traditional determinations were described,and a new method that use electrochemical oxidation as the pretreatment of determine iodine in laver by IC was Propounded.In section 2 ,the course of the experimentation was introduced .In section 3 ,the result and conditions of the experiment were discussed.In section 4 ,the brief summary was made.In chapter 4 ,an electrochemical reduction and its application to determining bromate in flour were studied. This chapter was divided into four sections:In section 1 ,the origin of bromate problem in flour and shortages of traditional determinations were introduced.In section 2 ,the experimentation was introduced.In section 3, the result and condition of the experiment were discussed. This section still discussed the structure and working process of electrochemical deoxidizer , condition of separation and deoxidization .In section 4, the brief summary was made.更多还原