Kinetic methods for determining water-soluble polymers

The effect of synthetic water-soluble polymers on the reactions of hydroquinone or 3,3′,5,5′-tetramethylbenzidine periodate oxidation with hydrogen peroxide is studied. A polymer solution was introduced into the reaction and a change in its rate was detected by photometry. Possible reasons for the effect of polymers are discussed, the role of the positive and negative charges of the polymeric chain and the nature of the indicator reaction are considered. The possibility of determining polyelectrolytes by their accelerating and inhibiting effect is demonstrated, including that, under the conditions of polyelectrolyte complex formation, and also by binding with a metal ion catalyzing the indicator reaction. Procedures are proposed for the simple and rapid determination of 3,6-ionene, polyanetholesulfonic acid, polyhexamethyleneguanidine (∼10−5 to 10−4 M, in terms of the monomer), polyethyleneimine and chitosans (∼10−7−10−6 M in terms of the monomer) in aqueous solutions, and also of polyethyleneimine by carrying out the indicator reaction on a silica surface (4 × 10−6 to 0.7 M in terms of the monomer).