Method of driving an atmospheric air pump in a capillary electrophoresis apparatus

A method of driving a pump, the method being used in a pressure-applying apparatus including:

• a flow passage;
• the pump configured to impart pressure into the flow passage by feeding air into the flow passage;
• an opening and closing valve that is disposed in the flow passage, and that is configured to open and close the flow passage;
• a pressure detector configured to detect pressure in the flow passage;
• and
• an atmospheric air open valve that is disposed in the flow passage, and that is configured to open an interior of the flow passage to atmospheric air, and
• the method comprising:
• feeding air into the flow passage by driving the pump while maintaining a state in which the opening and closing valve is closed and the atmospheric air open valve is opened;
• subsequently closing the atmospheric air open valve while continuing to feed air by driving the pump;
• and
• evaluating a state of the pump, based on one of:
• the pressure detected by the pressure detector at a time at which a predetermined time period has elapsed after closing the atmospheric air open valve while continuing to drive the pump;
• and
• an elasped time from closing of the atmospheric air open valve while continuing to drive the pump until detection of a predetermined pressure by the pressure detector.