Preparative liquid chromatograph

A preparative liquid chromatograph, comprising:

• a separation column for separating components in a sample;
• a detector for detecting the components in an eluate from the separation column;
• a chromatogram creation unit for creating a chromatogram in real time based on a detection signal obtained by the detector;
• a peak counting unit for sequentially counting peaks appearing on the chromatogram;
• a component trapping unit having a plurality of trap columns, for selectively introducing the eluate into any of the plurality of trap columns to trap the components;
• a recovery unit for recovering the eluate into a predetermined container;
• a flow path switching unit for switching a flow path to introduce the eluate from the separation column into either the component trapping unit or the recovery unit;
• a column number storage unit for storing the number of the plurality of trap columns provided in the component trapping unit;
• a determination unit for determining whether or not the number of peaks sequentially counted by the peak counting unit with a single sample introduction into the separation column has exceeded the number of the plurality of trap columns;
• and
• a control unit for controlling the flow path switching unit to introduce at least a portion of the eluate containing the component detected by the detector into the component trapping unit until it is determined by the determination unit that the number of peaks has exceeded the number of the plurality of trap columns, and to introduce at least a portion of the eluate containing the component detected by the detector into the recovery unit after it is determined that the number of peaks has exceeded the number of the plurality of trap columns.