The determination of acrylamide in environmental and drinking waters by large-volume injection – hydrophilic-interaction liquid chromatography and tandem mass spectrometry

A simple and sensitive analytical method was developed to quantify levels of acrylamide in environmental and drinking waters. The analytical method consisted of solvent exchanging acrylamide from 2 mL of water into 2 mL of dichloromethane using acetonitrile as an intermediate. The sample was then directly analyzed by large-volume (750 μL) injection – hydrophilic-interaction liquid chromatography and tandem mass spectrometry. The method detection limit and reporting level were 2.4 ng/L and 17 ng/L of acrylamide, respectively. The recovery of acrylamide during solvent exchange was 95 ± 2.8% and the matrix effects were 12 ± 2.2% in river water. The use of atmospheric-pressure chemical ionization reduced matrix effects; however, it also reduced method sensitivity by a factor of 2.2 compared to electrospray ionization. Matrix effects were compensated for by the use of an isotopically-labeled internal standard and the method accuracy was 89 ± 3.0% at 25 ng/L of acrylamide and 102 ± 2.6% at 250 ng/L of acrylamide. The precision of the method was less than 6% relative standard deviation at both 25 ng/L and 250 ng/L of acrylamide. Samples from a sand-and-gravel mine and a drinking-water treatment plant were acquired to demonstrate the method. The concentrations of acrylamide at the sand-and-gravel mine were up to 280 ng/L. In the drinking-water treatment plant, the concentration of acrylamide was approximately double in the finished drinking water when compared to other stages in the drinking-water treatment process. Disinfection or fluoridation may result in higher concentrations of acrylamide in finished drinking water; however, further research in this area is necessary.