Preparative chromatograph

A preparative chromatograph comprising:

• a liquid sender that sends a mobile phase;
• an injector that has a syringe pump for taking and discharging a sample, a sample loop for holding the sample temporarily and an injection valve that switches between a first state in which the sample loop is connected to a separation flow path through which a mobile phase from the liquid sender flows and a second state in which the sample loop is disconnected from the separation flow path, and injects the sample into the separation flow path by connecting the sample loop filled with the sample to the separation flow path;
• a separation column that is provided on the separation flow path and is to separate the sample that is injected into the separation flow path by the injector into components;
• a detector that is provided on the separation flow path and is to detect components generated by separation in the separation column;
• a fraction collector that is connected to a downstream end of the separation flow path and is to fractionate the components generated by separation in the separation column into a desired component and collect the desired component;
• an injection interval setter that is configured to set an injection interval time between injections of the sample into the separation flow path by the injector;
• a pump speed determiner, in a case where a sample intake operation by the syringe pump is started after the injection valve is switched from the second state to the first state, and a filling operation of filling the sample loop with the sample by the syringe pump is started after the intake operation is completed, is configured to determine an intake operation speed of the syringe pump that is required in order for the filling operation to complete before the injection valve is switched from the second state to the first state using the injection interval time set by the injection interval setter;
• and
• a controller configured to cause the injector to inject the sample at intervals of the injection interval time set by the injection interval setter by starting the sample intake operation by the syringe pump after the injection valve is switched from the second state to the first state, starting the filling operation of filling the sample loop with the sample by the syringe pump after the intake operation is completed and causing the syringe pump to operate at the intake operation speed determined by the pump speed determiner in the intake operation.