Optimization of stir bar sorptive extraction for the study of water soluble fractions of gasoline, diesel, and biodiesel using gas chromatography/ mass spectrometry

Accidental release of commercialized fossil fuels—gasoline, diesel, and biodiesel— through its processing and handling has posed a threat to the aquatic environment.  Studies have shown that constituents of these fuels can cause adverse health effects on aquatic organisms at various small concentrations.  Due to the continuing dependency of these fuels, the development of an efficient, effective, and environmentally conscious method to extract such compounds from relevant aqueous matrices is vital to monitor the release and to study toxicological effects of water soluble fractions of those fuels at low concentrations.  The objective of this study involves optimizing a green method, stir bar sorptive extraction (SBSE), using different methanol concentration and varying stirring time in the SBSE process.  Compounds found in water accommodated fractions of these commercialized fuels will be subsequently analyzed through thermal desorption (TD)-gas chromatography/ mass spectrometry (GCMS). Unlike other extraction techniques, SBSE uses practically no harmful organic solvent, offers great sensitivity for a variety of organic compound found at low concentration (in the ug/L range) in aqueous matrices.  The results of the optimized conditions and the profiles of the water accommodated fractions of these fuels in model fresh water and model sea water will be presented.