A pre-derivatized solid phase microextraction (SPME) fiber with N-phenylmaleimide was used to headspace-extract thiol components from sealed vials containing soiled oily waste water settling pond samples. Waste water samples were taken at different depths from three different settling ponds, which hold industrial washings from an oil-sand separation process. Such complex matrices preclude direct sampling methods. GC/MS analysis of extracts identified and quantified a variety of monosubstituted thiol compounds, based on an internal standard (thiophene). The developed automated method shows potential for low level detection of thiols from difficult aqueous sample matrices and achieved typical linear ranges of 10 µg L^-1 to 300 µg L^-1 with limits of detection (LDs) around 25 µg L^-1 for the thiols (1-butanethiol, 2-mercaptoethanol, 1-propanethiol, sodium ethanethiolate, sodium thiolmethoxide). Thiols can vary between 0.5% and 10% in crude oils and have water solubility suitable for consideration as potential chemical markers for water quality assessment.