Improved method for the determination of acrylamide monomer in water by means of gas-liquid chromatography with an electron-capture detector

Abstract

A gas-liquid chromatographic method involving electron-capture detection has been developed for the determination of an acrylamide monomer present in trace amounts in water. The method is based on bromination of the double bond by means of an ionic reaction and the 2,3-dibromopropionamide produced is extracted twice with 10 ml of ethyl acetate after salting out with sodium sulphate. The 2,3-dibromopropionamide from the reaction mixture is then cleaned up by using a Florisil column.

The calibration graph for the method is linear over the range 0–50 pg of acrylamide monomer and the limit of detection is 0.032 µg l^–1 for an aqueous standard solution. The yields of the brominated compound are 85.2 ± 3.3 and 83.3 ± 0.9% at fortification levels of 1.0 and 5.0 µg l^–1, respectively. Recoveries of acrylamide monomer from river water, sewage effluent and sea water spiked at a level of 0.20 µg per 50 ml are 99.4 ± 2.5, 101.3 ± 3.0 and 98.0 ± 3.2%, respectively. No interferences were observed from sea water or from 8.0% of ammonium ions present as ammonium bromide.