Microwave-assisted extraction (MAE) is an efficient sample preparation technique that has been demonstrated for different solid matrices (e.g. soils, sediments and biological tissues) and constitutes a valuable tool for the rapid treatment of solid samples in organometallic speciation analysis. A careful optimization of the conditions of the microwave extraction procedure is required, in terms of stability of the target compounds in a microwave field, prior to speciation analysis. Essential parameters for the optimization are the extraction medium, power applied and the exposure time. MAE is considerably faster than other sample preparation and extraction procedures: a typical sample treatment may take only 3 min.
An important drawback of microwave-assisted acid extraction or leaching is that analytes in the polar leachate have to be derivatized and transferred into a non-polar solvent to produce a solution suitable for GC analysis and this increasses the number of steps in the analytical procedure. This obstacle can be overcome by combining leaching, derivatization and liquid-liquid solvent extraction to produce directly a solution of the analytes for GC by the so called microwave-assisted derivatization solvent extraction (MADSE) technique.