the outer edge or through rotation snaps into the cut outs and can thus be moved closer to the cap fig1 shows a cartridge system according to the invention having a cartridge in a connecting system at the upper end all parts of the system are attached to the column or cartridge in the lower part they are for better clarity shown coordinated loosely to the column the cap 3 consists of two parts a threaded part 3 a with passage which is screwed onto the column consisting of sorbent 1 and cladding 2 a distribution element 3 b is placed against the threaded part the spacer ring 4 is connected to the cap 3 via a locking mechanism such as for example a snap in mechanism if it is not required the lock can be released and the spacer ring slid away to the column centre for use without pre column as shown in fig1 the divided supporting screw 5 a 5 b is placed against the spacer ring 4 this is carried out via a shoulder provided in the lower part of the supporting screw for connection of eluent feed and discharge the end piece 6 is screwed onto the supporting screw 5 a 5 b the end piece 6 consists of two parts the connector 6 a and a.