Liquid chromatography apparatus and liquid chromatography

A liquid chromatography apparatus, comprising:

• a sample preparation unit for preparing a sample from a specimen;
• a column configured to separate components of the sample;
• an eluent supplier for supplying as a mobile phase two or more types of eluent to the column;
• a first flow path directional valve capable of introducing a fixed amount of the sample to the column and capable of introducing the eluent to the column;
• an analyzer for analyzing a test solution composed of the sample components separated by the column and the eluent;
• and
• a controller for controlling operation of the sample preparation unit, the eluent supplier, the first flow path directional valve and the analyzer;
• wherein the eluent supplier is provided with a second flow path directional valve for supplying, to the first flow path directional valve, first and second eluents mutually supplied to separate ports of the second flow path directional valve,
• said second flow path directional valve includes an injection loop for retaining the fixed amount of the second eluent and the second flow path directional valve is rotatable, and
• the controller is configured to cause a fixed amount of the second eluent to be accumulated in the second flow path directional valve at least through controlling the rotation of the second flow path directional valve, and also cause the first eluent to be introduced into the second flow path directional valve from a port different from that of the second eluent, whereby at least a portion of the fixed amount of the second eluent and subsequently the first eluent are supplied from the second flow path directional valve to the column through the first flow path directional valve.