Using size-exclusion for improved extraction of trace organic compounds from landfill leachate

Abstract

Pharmaceuticals, plasticisers and other trace organic contaminants have been reported in landfill leachates, with most methods using hydrophilic–lipophilic balance cartridges for solid phase extraction. However, leachate has a high organic load and can quickly coat the cartridge media and prevent target compounds from being extracted. There are several solid phase extraction cartridges that offer size exclusion in addition to adsorption, where only small molecules are allowed to diffuse into the resin pores where adsorption in happening. Three cartridges with size exclusion properties were evaluated in comparison with hydrophilic–lipophilic balance cartridges for extraction of several trace organic contaminants spiked into landfill leachate. All three cartridges with size exclusion properties showed some improvement in extraction compared with hydrophilic–lipophilic balance, although the differences were not statistically significant at 95% confidence interval. Nevertheless, media with size-exclusion properties offers a viable alternative to hydrophilic–lipophilic balance for extracting small molecules of trace organics from complex environmental matrices.