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 2mL of water into 2mL of dichloromethane using acetonitrile as an intermediate. The sample was then directly analyzed by large-volume (750μL) injection - hydrophilic-interaction liquid chromatography and tandem mass spectrometry. The method detection limit and reporting level were 2.4ng/L and 17ng/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 25ng/L of acrylamide and 102±2.6% at 250ng/L of acrylamide. The precision of the method was less than 6% relative standard deviation at both 25ng/L and 250ng/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 280ng/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.