Soxhlet extractor

The Soxhlet extractor is a method which uses the reflux of the solvent and the siphon principle to continuously extract the solid matter with a pure solvent.

The finely ground sample is placed in a thick rod-shaped filter paper cartridge and placed in an extraction chamber. This fine grinding before extraction increases the solid-liquid contact area, which helps to shift the transfer equilibrium towards the solvent.

The solvent then continues to evaporate, while the extracted substances remain in the distillation flask and concentrate as the extraction takes place, but it is imperative that their boiling temperature is significantly higher than that of the extracting solvent.

A disadvantage of this hot method is that it can degrade heat-sensitive chemicals and you cannot work cold with this system.


  • Extraction of polycyclic aromatic hydrocarbons (PAHs) from polluted soils

  • Extraction of polychlorinated biphenyls (PCB) from polluted soils