Elution liquid control for a liquid chromatograph
First Claim
1. A liquid chromatograph, comprising a column, a liquid transferring pump for mixing and supplying a plurality of eluting liquids through respective opening-and-closing valves to said column so as to elute a sample to separate components thereof from each other when said sample is injected into said column, a sample detector for detecting said separated components, a pressure detector for detecting discharge pressure of said liquid transferring pump, and a controller for controlling a mixing ratio of said eluting liquids by varying opening-and-closing timings of said opening-and-closing valves according to a value of the discharge pressure detected by said pressure detector such as to shorten the period of time during which each opening-and-closing valve is opened as the value to the detected discharge pressure becomes larger.
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Abstract
In a low pressure gradient liquid chromatograph, two eluting liquids are transferred while they are being mixed with each other, whereby the mixing ratio thereof is changed with time. The mixing is performed by alternately opening and closing check valves provided in the liquid passages of the eluting liquids during a time period corresponding to the actual suction stroke of a plunger pump. The mixing ratio is determined by the time periods during which the check valves are opened, respectively. A detector is provided for detecting the pressure of the mixed liquid and the timing for opening and closing the check valves is changed in accordance with the detected pressure.
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Citations
5 Claims
- 1. A liquid chromatograph, comprising a column, a liquid transferring pump for mixing and supplying a plurality of eluting liquids through respective opening-and-closing valves to said column so as to elute a sample to separate components thereof from each other when said sample is injected into said column, a sample detector for detecting said separated components, a pressure detector for detecting discharge pressure of said liquid transferring pump, and a controller for controlling a mixing ratio of said eluting liquids by varying opening-and-closing timings of said opening-and-closing valves according to a value of the discharge pressure detected by said pressure detector such as to shorten the period of time during which each opening-and-closing valve is opened as the value to the detected discharge pressure becomes larger.
Specification