BUCHI Extraction System B-811 LSV - Manual (Page 20)

4 Description of function
20 B-811 Operation Manual, Version G
4 .3 The three steps in general
The complete extraction process is set with the operating panel and follows a defined program. The
process consists of three individual steps - Extraction, Rinsing and Drying – which runs automatically
according to the parameters set in the program.
4 .3 .1 Extraction
The sample is placed into the glass sample tube or thimble and put into the extraction
chamber. One of four available extraction methods can be chosen and set on the opera-
tion panel to be defined for the program.
Soxhlet Standard •
Soxhlet Warm •
Hot Extraction •
Continuous Flow •
During the entire process (step 1 to 9) inert gas such as nitrogen can be supplied to
prevent the oxidation of the analyte. In case of heat-sensitive analytes a keeping solvent
can be added in the beginning of the extraction to avoid a concentration to dryness.
For detailed information on the extraction methods, please refer to chapter 4.4.1 - 4.4.3.
Fig. 4.3: Extraction
4 .3 .2 Rinsing
Once the extraction is completed, the glass valve opens and an efficient rinsing is
performed; finally the glass sample tube is lifted up automatically. During the rinsing
process, the condensed solvent washes final traces of soluble matter from the
sample and from the interior of the extraction chamber.
Fig. 4.4: Rinsing