The first step in sample preparation of solid and semi-solid matrices, such as animal feed, soil, sludge, seed and nuts, is extraction with an organic solvent. DSP-Systems works together with Velp Scientifica, amongst others producer of SER-158/3 and SER-158/6 automated extraction systems. These automated systems which uses Twisselman and Randall (hot soxhlet alike) techniques are suitable for virtually any kind of solid and semi-solid sample.
The Solvent autoExtractoR SER-158/3 and SER-158/6 are closed extraction systems, meaning solvent exposure to laboratory personnel is minimized. Using the SolventXpress dispensing system, precise amounts of extraction solvents are automatically dispensed from the solvent bottle, directly into the extraction cells, After loading, the extraction process is started.
The extraction process
SER-158 processes 1-6 samples simultaneously in typically 2-3 hours. The automated process is performed in 5 subsequent steps and includes concentration/evaporation steps.
1. Extraction of samples in boiling extraction solvent (Randall principle)
2. Evaporation of 40-50 ml of extraction solvent which is collected in built-in recovery tank
3. Continued extraction where sample is just above the boiling extraction solvent (Twisselman)
4. Evaporation of remainder of extraction solvent which is collected in built-in recovery tank
5. After automatic extraction stop the sample is cooled down
The SER-158 saves substantial amounts of organic solvents and is by far more economical than pressurized liquid extraction. The automated solvent extractor SER-158 series are now available from DSP-Systems and he following benefits:
- Up to 5 times faster than classical soxhlet (cold solvent vs hot solvent)
- Low solvent consumption (and solvent recovery)
- Limited cost per analysis
- 3 to 6 extractions simultaneously
- Scalable multiplicity from 1 to 4 systems offers sampling for up to 24 units simultaneously.