The Dow Chemical Company

James W Pischke

Hamish Small

Russell T McFadden

Mark E Soderquist

Ruben L Krause

Charles H Moore

Apparatus and method for the chromatographic separation and analysis of ionic species. This process is carried out utilizing, in an ion separator column, the combination of a low capacity, high performance resin as the stationary phase, and a weakly ionized electrolyte as the eluant or developing reagent, to effect resolution of ionic species in solution. For anion separation, a weak base resin of low capacity and high efficiency is used as the stationary phase, and a solution of a weak base or water as the mobile phase. For cation separation, a weak acid resin of low capacity and high efficiency is used as the stationary phase and a solution of a weak acid as the mobile phase. Because the eluant employed has a very low background conductivity, it will register only insignificantly on the readout from the conductivity cell. Thus, the method of the invention obviates the need for the eluant suppressor or 'stripper' device used in conventional ion chromatography. The invention thereby enables continuous, uninterrupted measurements and eliminates the reservoirs, pumps, complex valving and electronics associated with such suppressor columns.

Weak eluant ion chromatography

Water-dispersible polymers of an acid salt of 2-aminoalkyl esters of monounsaturated monocarboxylic acid and at least one comonomer are prepared by dissolving the salt of that ester in a coupling solvent, mixing the comonomers as a separate feedstock and bringing the monomers together in a polymerization zone at a controlled rate so that the monomers remain in solution and polymerizing to substantial completion.

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Midland, MI, United States of America

James W Pischke