stationary apparatus which comprise the rest of the system thus the inlet fluid or liquid or mobile phase of the system is derived from suitable solvent reservoirs 30 which are coupled through a conventional pump 32 thence through a two way 6 port sampling valve 34 of conventional design and through a rotating seal 28 to the inlet 12 samples whose particulates are to be separated are introduced into the flowing fluid stream by this conventional sampling valve 34 in which a sample loop 36 has either end connected to opposite ports of the valve 34 with a syringe 38 being coupled to an adjoining port an exhaust receptacle 40 is coupled to the final port when the sampling valve 34 is in the position illustrated by the solid lines sample fluid may be introduced into the sample loop 36 with sample flowing through the sample loop to the exhaust receptacle 40 fluid from the solvent reservoirs 30 in the meantime flows directly through the sample valve 34 when the sample valve 34 is changed to a second position depicted by the dashed lines 42 the ports move one position such that the fluid stream from the reservoir 30 not flows through the sample loop 36 before flowing to the rotating seal 28 conversely the syringe 38 is coupled directly to the exhaust reservoir 40 thus the sample is carried by the fluid stream to the rotating seal 28 the outlet line 14 from the channel 10 is coupled through the rotating seal 28 through the channel 10 and out through the rotating seal 28 to a.