Separator column structural technical properties

Table 6-2. Structural-technical properties of the OmniPac separator columns.

Polyvinyl-based anion exchange resins have been available since 1984 from Interaction Chemicals (Mountain View, CA, USA) under the trade names ION-100 and ION-110 , respectively [24], According to the manufacturer, these macroreticular resins are stable at pH values between 0 and 14, thus allowing the use of a great number of eluents. In comparison to TSK Gel IC-PW, this stationary phase exhibits a much lower chromatographic efficiency [25], As an example, the separation of simple inorganic anions on ION-110 with salicylate as the eluent is shown in Fig. 3-10. The characteristic structural and technical properties of theses columns are summarized in Table 3-3. 

Silica-based anion exchangers are offered by manufacturers such as Wescan (Santa Clara, CA, USA), Separation Group (Hesperia, CA, USA), Toyo Soda (Tokyo, Japan), and Macherey Nagel (Diiren, Germany). Table 3-6 summarizes the characteristic structural and technical properties of the most important column packings available today. 

Applications of Ion Chromatography on Mixed-Mode Stationary Phases 643 Table 6.2 Structural and technical properties of the OmniPac separator columns. 

As shown in Fig. 4-12, a significantly better resolution between sodium, ammonium, and monoethanolamine is achieved when a crown ether is added to the mobile phase. A more elegant way to separate those cations is by functionalization of the ion-exchange polymer with crown ethers, implemented in the development of the lonPac CS15 [12]. The primary structural and technical properties of this separator column are identical to those of the lonPac CS12A. 

Whereas the 1,1,3,3-tetramethylbutyl side chain structure in t-octylphenol derived from diisobutene is usually the sole contributor, that in t-nonylphenol comprises a complex but nevetheless extremely useful mixture. Recent work on the separation of the isomers present on a cross-linked methylsilcone column by capillary GLC (ref. 47) could be useful in indicating the connection between structure and the properties in this valuable technical product. 

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