The term a “cyclonic separator” is used to designate a type of collection assembly that allows the material that has been extracted from the sample vessel to be collected through running the outlet tubing of the sample vessel/back pressure regulator at an angle along the walls of the collection vessel creating a cyclonic vortex that deposits materials on the walls of the collection vessel and the gaseous CO2 to evacuate to vent. Cyclonic separation minimizes the amounts of materials that get carried out with the gaseous CO2 through the venting process. This is very similar to the technology used in something as simple as the Dyson vacuum cleaner!
Some SFE suppliers use an actual SS pressure vessel to act as the cyclonic separator/collector and others employ vials and jars in place of the SS collection vessel, but both essentially carryout the same cyclonic separation/collection process. In the case of vials or jars, the outlet tube from sample vessel/BPR deposits extracted materials along the walls of the vial/jar and allows the CO2 to evacuate the collection vessel thus minimizing the loss of materials with the CO2 gas.