Molecular profiles of naphthenic acid fraction compounds from mine lease wetlands in the Athabasca Oil Sands Region

] species constituted 55-75% of the assignable spectrum and 3-4% NAs; in tailings ponds NAs constituted 47-51%. A relatively young (4-year-old) wetland built on a former tailings pond had NAFC concentrations between 65 and 80 mg/L, and NAs constituted 47% of the assignable spectrum. There was thus little apparent oxidation of NAFCs at this young wetland. The composition of NAFCs from one wetland (≥15 years old) supplemented with OSPM contained a greater proportion of oxidized species than tailings, suggesting NAFC transformation therein. These data suggest that while NAFCs are persistent in some wetlands, there is preliminary evidence for oxidation in mature wetlands.