Preparation & Applyings Of A High Performance Electrodialytic Membrane Suppressor For Ion Chromatography And Preparation Of PCD-1 Ion Chromatography Instrument

Ion chromatography (IC), which has rapidly grown in recent twenty years, is a useful new technique for analysis of ion. With it's some advantages such as selectivity, sensitivity, speediness, accuracy, IC has become the first choice for analysis of anion.Suppressor is the key part for IC instrument, and developing a high performance suppressor for IC instrument is quite important to gradient ion chromatography, to analysis of some ions which have strong affinities with the functional groups located on the surface of the pellicular ion exchange column packing.This dissertation consists of four chapters:(1) foreword (2)the preparation of high performance electrodialytic membrane suppressor for ion chromatography (3)the applying of the high performance electrodialytic membrane suppressor for ion chromatography (4) the introduction to the preparation of PCD-1 ion chromatography instrument.The first chapter includes the review the history of IC and the suppressor for IC, compare the characteristics of different kinds of suppressor, and the advance of the suppressor for IC.In the second chapter, we analyze the factors which maybe determine the capacity of the electrodialytic membrane suppressor for ion chromatography and reach that the limited polarized current of ion-exchange membrane and the efficiency of the direct current are the key factors to improve the capacity of the electrodialytic membrane suppressor. According the key factors we find, we bring forward a new conception: multilevel suppressor and design a new high performance suppressorwhose ion-exchange membrane has bigger areas and using three electrodes including one cathode(anode) and two anodes(cathode), at the same time we fill the suppression compartment with one kind of ion exchange resin which has moderate exchange capacity. According to our experiment's results, we find the new type suppressor has quite high working current efficiency and suppressing capacity. In most cases, the suppressor's current efficiency is over 90%; the suppressor can transform the NaOH (concentration:200mmol/L,flow rate: I .OmL/min,conductance: over 10000 i-i S cm') to pure water(conductance :8.9 it S cmIn chapter 3, the high performance suppressor is applied in determination some trace-amounts ions in plating solution, sewage .In this chapter, we also have a research on the gradient ion chromatography. All experiment results are satisfied.In chapter 4, we design a new conductivity detector for ion chromatography. The square wave is used as stimulating signal and the sampling is triggered by synchronization pulse at suitable time. By using these measures, the effects of doublelayer capacitance and polarization on the measurement are eliminated and the accuracy is improved. With the high performance suppressor, we try designing a new IC instrment.