Dispersant testing : a study on analytical test procedures

Crude oil is a complex mixture of hydrocarbons, ranging from small, volatile compounds to very large, non-volatile compounds. Analysis of the dispersed oil is crucial. This paper described Environment Canada's ongoing studies on various traits of dispersants. In particular, it describes small studies related to dispersant effectiveness and methods to improve analytical procedures. The study also re-evaluated the analytical procedure for the Swirling Flask Test, which is now part of the ASTM standard procedure. There are new and improved methods for analyzing oil-in-water using gas chromatography (GC). The methods could be further enhanced by integrating the entire chromatogram rather than just peaks. This would result in a decrease in maximum variation from 5 per cent to about 2 per cent. For oil-dispersant studies, the surfactant-dispersed oil hydrocarbons consist of two parts: GC-resolved hydrocarbons and GC-unresolved hydrocarbons. This study also tested a second feature of the Swirling Flask Test in which the side spout was tested and compared with a new vessel with a septum port instead of a side spout. This decreased the variability as well as the energy and mixing in the vessel. Rather than being a variation of the Swirling Flask Test, it was suggested that a spoutless vessel might be considered as a completely separate test. 7 refs., 2 tabs., 4 figs