There is provided a method for concentrating and separating water soluble polymeric material containing at least 50% by weight of mers which are those of acrylic, methacrylic or maleic acid or mixtures thereof from an aqueous system containing said polymeric material and other soluble ionic material, which method comprises:… (a) adjusting the pH of said aqueous system to suppress ionization of said polymeric material,… (b) selectively adsorbing the ionization suppressed polymeric material on a nonpolar adsorbent, and… (c) desorbing the adsorbed, ionization suppressed, polymeric material from the adsorbent with a displacement fluid. … There is also provided a kit of parts suitable for carrying out the above method which comprises (1) a filter capable of removing from said aqueous system particulate solids and/or oil droplets, (2) a container having therein non-polar adsorbent capable of selectively adsorbing said water soluble polymeric material from said aqueous system, (3) syringe means attachable to said filter means and to said adsorbent container and, optionally (4) at least one of the following, viz (a) material capable of lowering the pH of the said aqueous system to suppress ionization of said water soluble polymeric material, (b) pH measuring means, (c) a liquid for conditioning by wetting the non-polar adsorbent, (d) fluid for displacing from the non-polar adsorbent the water soluble polymeric material adsorbed thereon, (e) assay means for determining the amount of desorbed water soluble polymeric material in the displacement fluid and (f) assay means for determining the amount of non-adsorbed organophosphate, organophosphonate or inorganic phosphate scale inhibitor in the effluent from said adsorbent container.