In various analysis studies, the extraction step is an indispensable step of many analytical processes. Soxhlet extraction was first developed by Soxhlet in 1879 and has been widely used until recently. Even today, it is used in many laboratories. However, in recent years, there has been a trend towards advanced extraction techniques. Because new developments have been experienced in the field of automation and the extraction time has been shortened. Reduction in residual organic solvent consumption and less pollution in laboratories. On the other hand, sample preparation costs have decreased.

Together with new technologies, new insights have been developed in the principles of extraction. For example, microextraction and miniaturization came to the fore. In the sample preparation process, known extraction techniques have been replaced by new methods such as microwave assisted extraction, supercritical liquid extraction, pressurized liquid extraction and sound waves assisted liquid extraction. The common point in all of them is the increase of extraction speed and the possibility of working under high temperature and pressure.

Among the new extraction methods, the supercritical liquid extraction technique is shown as the green trend. Since supercritical fluids are used for extraction purposes, this method has emerged as an environmentally friendly application. A supercritical fluid is a fluid whose temperature and pressure values ​​are above critical values. In this method, carbon dioxide gas is used.

Environmentally friendly laboratories use environmentally friendly solvents when extracting the desired material from the raw material. They are readily available and the operating conditions give minimal damage to the environment. It is therefore preferred to obtain natural extracts. The important point here is the choice of supercritical fluid. In the selection of supercritical liquids, especially in the food sector, the solubility of the substance must be stable, safe, and free of poisoning.

In authorized laboratories, water extraction is carried out in fractional studies that can be extracted at maximum within the scope of chemical tests. In these studies, globally accepted test methods are followed.