Variability of the ancient organic supply in modern humus

Fig. TLC elution of extracts with CH 2 Cl 2 allowed to fractionate ketone-, alcohol-and fatty acid enriched fractions (Fig. The fractions were recovered from the plates by scratching the silica gel toward aluminium foil with a spatula, by transferring the silica gel via a glass funnel (fitted with a teflon tube) on a pipette Pasteur plugged with cotton wool [3], then by elution of a solvent (~ 2 mL) into a 2 mL vial using CH 2 Cl 2 except for the fatty acid fraction (ethyl acetate). Analyses of the fractions by gas chromatography coupled to mass spectrometry will be reported elsewhere.