Soxhlet and Randall Extractor

Our fat extraction system is specially optimized to determine crude fat or other components soluble in organic solvents according to the universally known Solvent extraction method, including both Randall and Twisselmann methods.

Its flexibility to analyze a wide variety of samples ranging from food to environmental soil analysis makes our extractor suitable for multiple settings and applications.

SX-6 MP is designed to guarantee accurate and precise results according to the international standardized methods such as AOAC, ISO, AACC, DIN and EPA.

For the analysis of food, feed, soil, detergents, polymers, paper pulp, fibers, gums, textiles, pharmaceuticals and petrochemicals.

Technical data sheet

Installation Guide

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  • Heating by an electric plate with armoured heater to assure homogeneous distribution of heat.
  • Control of temperature by P.I.D. microprocessor action and probe Pt100 class A.
  • Over temperature safety control by independent thermocouple.
  • Compatible Vitón® and EPDM gaskets.
  • In accordance with standardized international methods: AOAC, ISO, AACC.
  • Case made of stainless steel AISI 304 painted with epoxy resin.



  • Independent programmation of temperature and extraction times for “boiling”, “rinsing” and “recovery” phases.

Technical Data

  • Temperature range: room temp. +5 ºC to 220 ºC.
  • Solvent volume: up to 50 ml.
  • Solvent recovery: up to 95%.
  • Reproducibility: ±1%.
  • Extraction thimbles: Øext 26 x 60 mm.
  • Programmable boiling extraction time.
  • Programmable rinsing extraction time.
  • Programmable solvent recovery time.
  • Grade of protection: IP65.


Components supplied with the equipment

  • 25 Cellulose extraction thimbles.
  • 12 Extraction thimble supports.
  • 12 Aluminum extraction vessels.
  • 6 Magnetic adapters.
  • 6 EPDM gaskets.
  • 6 Viton® gaskets.
  • 2 Racks for extraction thimbles.
  • 2 Racks for extraction vessels.
  • 1 Aligning rack for extraction vessels.
  • 1 Tong for an individual manipulation of extraction vessels.
  • 1 Tong for a simultaneous manipulation of 6 extraction vessels.
  • 2 Silicone tubes 1,5m (ø 8 x 14).


The traditional Soxhlet method, invented by Franz von Soxhlet in 1879, is the most popular method for fat extraction. It is a standard procedure that provides good analyte recovery, however the extraction procedure is long (it can last 18-24h) and uses a significant amount of solvent.
Soxhlet extraction consists in placing a previously dried sample inside a thimble made of cellulose and then it is loaded into the extractor, which is connected to a flask containing a solvent and a condenser. The solvent is heated and evaporated, the hot solvent vapor then travels up to the condenser, where it cools and falls onto the sample in the thimble. The chamber containing the sample slowly fills with condensed solvent until, when almost full, it is emptied by a siphoning action back into the solvent flask. During each cycle, a portion of the soluble components in the solvent are extracted. This cycle is repeated several times until all analyte is separated from the sample.
In order to improve effectiveness of Soxhlet extraction, alternative methods that use the same extraction principle but have some improved features have been developed. Randall method, suggested by Edward Randall in 1974, is an example of this improvement as it typically allows the reaction to be four times faster and guarantees solvent recovery. SX-6 MP extractors can be programmed with different extraction steps according to Randall analysis as seen on this page figure.
Twisselmann extraction, also known as continuous economic extraction requires only one extraction position, between boiling and rinsing. The solvent placed in the extraction cup is heated and evaporated, these vapors pass through the sample and reach the condensation chamber, once liquefied, the solvent falls onto sample and is collected again in the extraction cup. Thus, both vapor and liquid forms of solvent simultaneously and continuously extract all lipid content from the sample. After all analyte has been collected, solvent can also be recovered.

Firstly, the sample is immersed in hot solvent, where absorption of sample fat content by the solvent is continuous by both immersion and reflux.

Secondly, the sample is lifted from condensed solvent contact. In this step, absorption of sample fat content by the solvent is continuous only by reflux.

In the final step, the solvent tank valve is closed and the solvent is collected for future reuse. The fat content is deposited at the bottom of the reaction flask.

ModelSX-6 MP
Externals dimensions L x D x H680 x 330 x 580 mm
Power 1500 W
Voltage*230 V
Weight 46 Kg
Frequency 50/60 Hz
Solvent recovery Up to 95 %
Temperature accuracy±0‚5ºC
Sample capacity by batch6 unidades
Sample capacity by day36 unidades

*Also available with a voltage of 115 V.



Extraction thimble (25 units)

Extraction vessel (6 units)