Soxtherm

Washing/soakinga Shake-flask extraction12 In-vial LSEa Reflux extraction Soxhlet/Soxtec /Soxtherm extraction... 

Soxtherm , FEXTRA and intermittent extractions. The newer methods (SFE, ASE , MAE) invariably operate at pressures above atmospheric. Micromethods of solvent extraction have also been described [57,58]. 

Principles and Characteristics In boiling under reflux procedures a small amount of ground polymer (typically 3g) is placed in a headspace jar (typically 100 mL) and solvent (typically 30 mL) is added. After sealing, the jar is placed in an oven at a temperature where the solvent slowly refluxes. The solvent is, therefore, at the highest temperature possible without applying an external pressure. Consequently, reflux extractions tend to be much faster than Soxhlet extractions. Examples are Soxtec , Soxtherm , FEXTRA and intermittent extraction. Whilst, in theory, partitioning of the analyte between the polymer and solvent prevents complete extraction, this hardly ever constitutes a problem in practice. As the quantity of solvent is much larger than that of the polymer, and the partition coefficients usually favour the solvent, very low additive levels in the polymer result at equilibrium. Any solvent or solvent mixture can be used. 

Soxtherm extractors automate them. The patented Soxtherm process consists of five (automatic) stages ... 

Soxtherm can be considered as Soxhlet with hot extraction (at the boiling point of the solvent in the first stage). 

Soxtherm can be used for a variety of substrates, such as plasticisers, and additives in plastics and rubber, fibre and textile coatings, colorants on textiles, fat in food, oils and lubricants, fertiliser coatings, etc. Specific reports are scarce. EPA method 3541 has adopted automated Soxhlet extraction [151]. 

The author and publishers wish to thank C. Gerhardt, GmbH Co. KG for providing the cover image Soxtherm an original painted by Douglas Swan (1997). 

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