Dedicated Analytical Solutions

FOSS service and support

More than just an instrument, FOSS solutions are supported by a global network of more than 250 highly trained service engineers

FOSS Support

ST 243 & 255 Soxtec™

Semi-automated solvent extraction units

The ST Soxtec series from the semi-automated Labtec Line is a solvent extraction system for fast and safe determination of soluble material in food, feed, soil, polymers, paper pulp, textiles etc. Typically five times faster than classical Soxhlet equipment, Soxtec™ systems provide rapid analysis with absolutely no loss in precision or accuracy.


ST 243 Soxtec™

ST 255 Soxtec™

Thimble size

26 x 60 mm thimble
(30 ml)

33 x 80 mm thimble
(65 ml)

Sample positions



Mandatory *

What can automated chemical analysis do for you?

Contact your local FOSS representative to discuss possibilities


Crude fat, Total fat and Extractable matter

Sample types

Fat in food and feed. Extractable matter in textile, paper pulp, plastics, rubber etc. PCB and PAH in soil and sludge (the Soxtec is a preparatory step to GC-MS)
Laboratory solutions

Method for crude fat analysis

Fat is extracted using a solvent and the Randall modification of the Soxhlet method. The sample is submerged in boiling solvent prior to rinsing in cold solvent, reducing the time needed for extraction. The solvent dissolves fats, oils, pigments and other soluble substances. After extraction, the solvent is evaporated and recovered by condensation. The resulting fat residue is weighed back after drying; following AOAC approved methods.

Laboratory solutions

Method for total fat analysis

For total fat determination, the sample is is hydrolyzed in acid. Hydrolysis makes chemically or mechanically bound fats accessible to solvent extraction. The mixture is cooled and filtered. The residue is washed, dried and submitted to the above extraction procedure.

ST 243 Soxtec™

A three-step, six position solvent extraction system, consisting of an Extraction Unit and a Control Unit. The three-step extraction procedure consists of boiling, rinsing and recovery. Typically solvent recovery is 80%, with only ~10 ml solvent used per sample. Sample preparation prior to GC/HPLC work is also possible using a specially designed seal.

ST 255 Soxtec™

A three-step, six position solvent extraction system, consisting of an Extraction Unit and a Control Unit. The sample is weighed into thimbles and inserted in the Extraction Unit. Solvent is added in a closed system. The 4-step extraction procedure consists of boiling, rinsing, recovery and pre-drying.

Laboratory solutions

Hydrolysis with the SC 247 SoxCap

For total fat analysis, the sample is transferred from the SC 247 SoxCap hydrolysis unit to the extraction unit. After hydrolysis the glass capsule is simply turned upside down, a cellulose thimble is fitted on top and the capsule is placed in the Soxtec for the solvent extraction step.

Read more

We make your user experience better by using cookies. If you continue on this website you agree to the use of cookies. Read more about cookies here.