The chemical detection of polyacrylamide

The earliest chemical methods developed for the assay of polyacrylamide were based on turbidimetric methods in which the polymeric material was reacted with a reagent to form a barely soluble turbid compound. A method based on the reaction of hydrolysed polyacrylamide with a quaternary ammonium cation was proposed by Michaels and Morelos (1955). This method was later modified by Grummet and Hummel (1963), and it has been applied and automated for determining polyacrylamides and other anionic 

Scoggins and Miller (1975,1979) developed a method for the determination of acrylamide-based polymers in brine solution which depends on the presence of the primary amide group, —C=ONH2- This method depends on the bromine oxidation of the amide functional group through the following reaction at pH 3.5  

The excess bromine in this reaction is destroyed by the addition of sodium formate through the following chemical reaction  

The brominated polymer is then hydrolysed rapidly with water to produce hypobromous acid (HOBr) as follows  

The hypobromous acid released in the above reaction then reacts under acid conditions with the iodide ion (I ) to produce free iodine (12)  

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