Study On Electrodialysis Pretreatment Technique Used For Sample Neutralization, Oxidation, Extraction And Its Application In Ion Chromatography

As ion chromatography has good sensitivity for the common anions and cations, the sample preparation technique is always of weakness for ion chromatography. The purpose of sample pretreatment is to eliminate sample matrix interferences, decrease matrix concentrations, neutralize the alkaline/acidic samples, condense and enrichment the analytes and so on, so that the samples after pretreatment can be analyzed by ion chromatography. Among all the sample preparation techniques for ion chromatography, electrodialysis pretreatment has a good advantage and is of importance in the analysis.In this dissertation, several types of electrochemical pretreatment devices for the analysis by ion chromatography were designed and developed, based on the electrochemistry principle. In addition, the devices were applied to the determination in the real samples of tobacco, urine, chemical and so on.There are four parts in this dissertation:Chapter 1, some theories on the sample preparation technique for ion chromatography and applications by electrodialysis pretreatment were reviewed. Additionally, the technical scheme and innovation of this dissertation were introduced.Chapter 2, several kinds of electrochemical neutralization devices were designed and compared. The device with good performance was chosen to neutralize the acidic sample solution and applied to the determination of the analytes of potassium, magnesium and calcium in tobacco samples by ion chromatography.Chapter 3, a new method for the simultaneous determination of fluorine and iodine in urine by ion chromatography with electrochemical pretreatment has been developed. The pretreatment was performed in a novel electrochemical oxidation-neutralization device, in which iodide of the sample was oxidized to iodate and the alkaline digestion sample solution was neutralized.Chapter 4, a novel electrochemical extraction-neutralization device was designed to eliminate sample matrix interferences and enrichment the analytes. It was successfully applied to the determination of the trace anionic impurities in hydrogen peroxide by ion chromatography.