Comparison of the Levels of Chloride Ions to the Characterization of Oil Sands Polar Organics in Natural Waters by Use of Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Oil sands processed water (OSPW) is known to have elevated levels of chloride ions above the background in the Athabasca River. The solubility of oil sands polar organics (including naphthenic acids) can be affected by the salt content of the water, which in turn is hypothesized to affect the distribution of organics in aquatic environments. Salt interactions are shown to affect the distribution of polar organics observed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry of environmental samples (OSPW, river water, and groundwater). Acidic oxygen-containing species (O-n, in which n = 2-10) were prevalent in most samples, the relative distribution of which depended upon both the sample location and chloride levels of the water. Likewise, the distribution of heteroatomic sulfur species (OnSs species, in which n = 2-8 and s = 1-2) also depended upon the sample location and chloride ion concentration of the waters investigated. Environmental monitoring of oil sands polar organics and naphthenic acids should therefore be conducted concurrently with the measurement of chloride ions (and other salts).