Ion exchange chromatography techniques

Ion-exchange chromatography techniques that provide cationic surfactant residues suitable for a conductivity analysis are also developed [47,48]. They usually employ strong cation exchange columns and a mobile-phase based on an organic solvent (acetonitrile or... 

Ion exchange experimental techniques have been described in monographs [1-6] and reviews [7-14]. Information on high-speed ion exchange chromatography techniques can be found in books [21-26] and assays [27,29,32,34,57,73-75]. For instrumentation of LC see also chapters 4.1-4.4 of this volume. 

The free oil can be determined by an ion exchange HPLC technique. A solution of the sample in ethyl alcohol is analysed by high-performance ion exchange chromatography using a specially prepared ion exchange resin stationary phase, ethanol mobile phase, and differential refractive index detection. 

Hence, once a B ion is freed from the resin, it is immediately complexed and there is much less tendency for it to be resorbed lower down the column as would happen with a stable cationic species. This is an illustration of separation by elution analysis. Its most important application is in the separation of rare earths. When used on a laboratory scale in chemical analysis, this separation technique is known as ion-exchange chromatography. 

The chromatographic pumps and flow path used in IEC must be resistant to corrosion. For this reason, polymers such as poly(etheretherketone) (PEEK , ICI Americas Wilmington, DE) have entered into widespread usage in ion chromatography. Electrochemical detectors may also be subject to corrosion by certain ions. This chapter will review the chromatographic materials, detectors, and applications of ion exchange chromatography. For some classes of compounds, where reversed phase or normal phase alternatives may have been developed, alternative separation techniques will be presented. 

Kirkland, J. J., Techniques for high-performance liquid-liquid and ion exchange chromatography with controlled surface porosity column packings, ]. Chromatogr. Sci., 7, 361, 1969. 

Ionic solutes can be separated by ion-exchange chromatography using microparticulate resins or bonded ion-exchangers based on microparticulate silica. Such separations are often achieved more easily by ion-suppression or ion-pairing techniques, which use bonded phase columns in the reverse phase mode. 

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