Extraction procedures (concretely: solid-liquid extraction process) are used to separated soluble components from a sold sample.
- Determination of fat content in food
- Determination of contamination (e.g. PCB, armament waste) in soil samples
- Examination of the components of natural substances
Making coffee is also an extraction process. But in the lab, this involves separating the searched components as fully as possible from the sample, under defined conditions and not unnecessarily diluted. In the lab, organic solvents such as hexane or petroleum spirit are often used as extractants. What all extraction processes have in common is that as many components as possible are to be separated with a defined quantity of solvent. This can be achieved by constantly evaporating the solvent and having it drip into the samples from a reflux cooler. Unlike the coffee machine, the same solvent is continuously sent back through the sample. The extracted component enriches itself in the distillation flask.