Pipette Pasteur extraction: A fast, convenient, exhaustive and environmentally friendly method for the extraction of solid samples

A simple and fast (~5 min) method has been set up to extract small soil samples (~300 mg) by elusion of a small volume of methylene chloride (2000 μl) on a modified Pasteur pipette. Pasteur pipette extraction thus allows us to minimize sample losses by evaporation, degradation, contamination, and experimental handling. Moreover, shake and ultrasonic extractions were found to give lower extract yields, amounting respectively to 1.8 and 1.9 mg.g^-1 dry weight, than pipette Pasteur extraction (3.0 mg.g^-1). This method may be applied to extract the soluble organic matter of any kind of solid sample such as sedimentary rocks, coals, aerosols, food and biological substances; prior molecular analyses such as gas chromatography coupled to mass spectrometry.