Anal. Chem. 1996, 68, 3917-3921
Determination of Acrylamide in Emulsion Polymers by Pyrolysis-Solvent Trapping-Gas Chromatography Frank Cheng-Yu Wang* and Bruce Gerhart
Analytical Sciences Laboratory, Michigan Division, The Dow Chemical Company, Midland, Michigan 48667
Acrylamide polymerized into the polymer backbone was qualitatively identified by using a method combining pyrolysis, solvent trapping of pyrolysis products, and gas chromatographic separation with a detection system. In this study, two solvents (water and methanol) and three detection systems (flame ionization detector (FID), mass selective detector (MSD), and atomic emission detector (AED)) were compared for efficiency of trapping and detection of acrylamide in an emulsion polymer. The advantages of each solvent and detection system as related to acrylamide analysis are discussed. Organic amides (such as acrylamide and methacrylamide) are commonly used with other monomers in emulsion polymer (latex) systems. The major functions of organic amides are similar to those of the organic acids in emulsion polymers. They can provide stability, enhance adhesion, expand the swellability in water, increase copolymer strength, and define the surface chemistry. In addition, the organic amides can provide better compatibility with pigments and extenders. Acrylamide is one such organic amide commonly used in emulsion polymerization. Because these amides are normally added at low concentration (1-2.5% by weight), qualitative and quantitative identification is challenging. The presence of acrylamide in emulsion polymers can be determined either in the serum or in the solid polymer. The aqueous serum phase can be extracted and filtered to permit identification and quantitative determination of residual acrylamide by a suitable polarography,1 liquid chromatography (LC),2 or gas chromatography (GC) technique.3 Because of safety concerns, the residual acrylamide in an emulsion polymer system generally is treated with tert-butyl hydroperoxide (TBPH) to reduce the residual acrylamide concentrations to
