Patent ID: 6911151

Claim:
An apparatus for the liquid chromatographic separation of substances under pressure, comprising a plurality of liquid chromatographic separating which are disposed in parallel, a single pumping unit in the form of one or two pumps for supplying a liquid to the separating lines a sample holding system for holding a plurality of samples and allowing simultaneous parallel withdrawal of the samples, an injection system for parallel transport of the samples from the sample holding system and a liquid from corresponding separating lines to corresponding parallel separating columns wherein each of the separation lines has a separate flow control unit comprising a flow controller, a total pressure meter and a flow meter, wherein the flow controller is disposed upstream of the injection system, a detector means connected to an evaluation and control unit for determining retention time for each of the separating columns based on data from the corresponding flow meter and total pressure meter, and means for independently adjusting flow via the corresponding flow controller in each of the separation lines based on the detected retention time, such that an actual retention time in all of the separating columns may be rendered the same.