Automatic installation for liquid chromatography

An automatic installation for liquid chromatography, of the type comprising a chromatographic column, a container of the product to be fractionated, and at least one container of eluent, said containers being connectable with the top of the column via an injection pump, detection means connected to the output of the column and supplying at least one measuring signal representing a characteristic of the liquid discharged from the bottom of the column, means for collecting fractions with at least one collector container which is connectable with the base of the column via an automatically-controlled output valve, and a control unit receiving the measuring signal and comprising means for controlling the fractions collecting means, wherein:

• a level detector is provided for each container of product to be fractionated and of eluent, which detector produces a low level signal whenever the level of the liquid inside the container is below a predetermined threshold,
• automatically controlled feed valves are mounted between the injection pump and each container of product to be fractionated and eluent, respectively,
• a measuring device is provided for the container of the liquid to be fractionated, to allow injection into the column of a pre-determined quantity of said product, and
• the control unit comprises:
• a control device receiving the or each measuring signal produced by the detection means and controlling on the one hand, the feed and output valves and, on the other hand, the measuring device, to produce successive cycles of chromatography each one including at least the consecutive operations of injecting into the column a set quantity of the product to be fractionated, of admitting in the eluent, and of collecting a fraction;
• and a safety device connected to the level detectors to control the stoppage of the pump and prevent admission of product to be fractionated or of eluent into the column when the corresponding level detector produces a low-level signal.