Polyacrylate Anion Exchangers

A HEMA-based anion exchanger developed by Alltech has been described as a universal stationary phase for the separation of a wide variety of anions [6,7]. This anion-exchange resin has been compared to agglomerated peUicular anion exchangers for the separation of anions by chemically suppressed 1C. The HEMA-based columns exhibit higher capacities for all anions and particularly for weakly retained anions such as fluoride and formate, which were completely resolved. The HEMA columns could be used for both isocratic and gradient techniques. 

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Hubicki Z., Leszcz3mska M. Studies of sorption of Pd(II) microquantities on strongly basic polyacrylate anion exchangers. Desalination 2005 175 289-295. 

A range of polyacrylic anion-exchange resins has been produced in recent yeais. The exact structure and method of manufticture have not been published, but it is clear that they contain quaternary ammonium groups (or in the case of the weakly basic materials, amino groups) attached to an acrylic skeleton. Thqr are ysically robust materials, with good operating characietistics, and are serious competitors to the polystyrene resins. 

The preparation and properties of polyacrylate anion-exchange resins by AUtech has been described as a universal stationary phase for the separation of a wide variety of anions [6, 7]. The Allsep anion column contains 7-pm particles packed into columns of various lengths. The resin is methacrylate based with quaternary ammonium functional groups The A2 anion column also has methacrylate, but has a quaternary amine with alkenol, rather than alkyl, groups. It is relatively hydrophilic and resolves acetate and formate from fluoride and chloride. Both columns have a broad pH range (pH 2-11) and can be used with 0-100% of an organic eluent modifier. 

Uno Q1 and Q6 (strong anion exchange, monolithic stationary phase) Polyacrylic acid Whey proteins (a and /3-lactalbumins) 34... 

Anion-exchangers (sometimes abbreviated as anex ) may be polymer-based (commonly polystyrene or polyacrylate) or silica-based. Although many types of anion exchangers are available for ion chromatography, the strong-base type with quaternary ammonium functional groups is the most common. These normally come in the chloride form, for example, Solid-N RsCl. ... 

A comprehensive study of coated anion-exchange resins provides some valuable insights [20]. Of several coating materials tested, cetyl pyridinium chloride (CPI) was found to be the most satisfactory. Static coating was employed with 1-3 x I0 M CPCI in 3 % (v/v) acetonitrile-97 % water. Coating of a polyacrylate resin (Rohm Haas XAD-8) gave sharper chromatographic peaks for anions than the more hydro-phobic PS-DVB resin (Hamilton PRP-1). 

The most commonly used resins are gel type sulfonated cation exchangers or anion exchangers with a quaternary ammonium functional group. The exchange capacity of the resins used is generally higher than those used for ion chromatography. The resins may be either styrene-divinylbenzene copolymeric beads or polyacrylate beads. The diameter of the beads should be small and uniform. Resins with a 5 pm bead diameter are now available. 

Figure 8. Influence of acetic acid concentration on C.f Acid Orange 7 uptake by the anion exchangers of the polyacrylic matrix...

Figure 9. Influence of anionic surfactant sodium dodecyl sulfate (SDS) on uptake of C.I. Add Orange 7 by the polystyrene anion exchangers (a) as well as the polyacryUc and phenol-formaldehyde anion exchangers (b), of C.I. Reactive Black 5 by the polystyrene ardon exchangers (c) as well as the polyacrylic and phenol-formaldehyde anion exchangers (d) and of C.I. Direct Blue 71 by the polystyrene anion exchangers (e) as well as the polyacrylic and phenol-formaldehyde anion exchangers (f)...

According to a recent publication, the separation of protein and plasmid DNA as well as that of DNA and lipopolysaccharides is possible by displacement chromatography. Linear polyacrylic acid (Os-type, Mw 5100 g/mol) was successfully used as displacer. A particularity was the fact that conventional stationary phase materials based on porous anion exchanger or... 

Tanaka et al. devised a method for determination of the ions in acid rain in a single run [18]. The column used contained a polyacrylate weak-acid cation exchange resin (TOSOH TSK gel OA-PAK, 300 x 7.8 mm, 5 pm particle size). Water alone as the mobile phase only separated weak acid anions from strong acid anions as a group cat-... 

A method for determination of cations and anions in a single run was described in Section 8.6. The column was packed with a polyacrylate gel cation exchanger. It appears that sample cations were separated by cation chromatography and anions by ion-exclusion chromatography. 

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