PURPOSE: To improve measuring accuracy by increasing gradually the change- over rate of eluates so that the eluates are smoothly changed over.
CONSTITUTION: The opening and closing of a solenoid valve are repeated by changing adequately the opening and closing time of the solenoid valve in the stage of changing over plural pieces of eluate reservoirs by opening and closing successively the solenoid valve. More specifically, the time when the eluate 1b is passed is gradually increasd as shown by hatches. The change-over rate of the eluate 1b increases accordingly gradually so that the eluate 1a can be smoothly changed over to 1b along a linear gradient 15. A base line 16 changes smoothly as well and smooth peaks 17, 18 are obtd. The smooth correction of the base line 16 in the data processing unit is thus made possible and the exact chromatogram is obtd.
FUJII YOSHIO
ITO MITSUO
