Divinyl sulfone chromatography

Chromatography by ion exchange on a sulfonated poly(styrene-co-divinyl benzene) phase has been proposed as a replacement for titrimetry.57 Eluted by a dilute solution of a neutral salt such as sodium ethanesulfonate, the conductance of the protons can be measured in the absence of a suppressor from sub-millimolar to molar concentration. The response factors of mono-, di-, and trichloroacetic acid and of o-phthalic acid were large and essentially equivalent to ethanesulfonic acid, while the response factor of acetic acid was far smaller. A syringe pump has generated pressures as high as 72,000 psi (5000 bar) in a capillary column packed with 1 p particles, generating a fraction capacity of 300 peaks in 30 minutes.58... 

Chromatographic System Determine as directed under Chromatography, Appendix HA, but use a liquid chromatograph equipped with a differential refractometer detector and a 30-cm x 7.8-mm (id) column packed with 25-pm diameter beads of silver bonded to sulfonated divinyl benzene-styrene copolymer (Aminex HPX-42A, Bio-Rad Laboratories, or equivalent). Maintain the column at a constant temperature of 65° 10°, and the flow rate at 0.3 to 1.0 mL/min. Use deionized water as the mobile phase. 

Finally, ion chromatography can be used to determine the a-sulfo fatty acid esters. The chromatographic column is a nonpolar polystyrene/divinyl-benzene column and the ion pair reagent is 0.005 M ammonia. In order to reduce the elution time, acetonitrile is added as a modifier with increasing concentration. This gradient technique makes it possible to simultaneously separate ester sulfonates and disalts by chain length. Determination is achieved by standards with defined chain length [115]. 

Ion-exchange chromatography (lEC). Stationary phases for the separation of mixtures of ionic solutes, such as inorganic cations and anions, amino acids and proteins, are based either on microparticulate ion-exchange resins, which are crosslinked co-polymers of st)U ene and divinyl benzene, or on bonded phase silicas. Both types have either sulfonic acid cation-exchange sites (-SO3 H ) or quaternary ammonium anion-exchange sites (-N RjOH") incorporated into their structures. 

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