OPTIMIZATION OF THE MICROWAVE-ASSISTED SOLVENT-EXTRACTION OF PETROLEUM-HYDROCARBONS IN MARINE SEDIMENT AND SOIL

A microwave-assisted solvent extraction (MASE) technique was developed for the quantitative extraction of gasoline- and diesel-range petrole um hydrocarbons (PHs) from soil and marine sediment samples. The influ ence of different extracting solvents, extraction temperature and dura tion of extraction on the recoveries of PHs was evaluated using a two- level orthogonal array design (OAD) with a OA(8)(2(7)) matrix. Gas chr omatographic-mass spectrometry (GC-MS) in multiple selective ion monit oring (MSIM) mode was used for the analysis of the PHs in environmenta l samples. The spiking range of the PHs in the environmental samples w as between 1 to 1000 mu g/g. Good recoveries (>80%) could be obtained for most of the PHs using the optimum MASE conditions. The limit of de tection (LOD) achieved by the GC-MS-MSIM was 0.02 mu g/g. A preliminar y survey for the levels of PHs in marine sediment and soil samples fro m different parts of Singapore was carried out using the method.