US 12,292,422 B2
Liquid chromatograph and flow path cleaning method in liquid chromatograph
Yuka Fujito, Kyoto (JP); and Logan Miller, Columbia, MD (US)
Assigned to SHIMADZU CORPORATION, Kyoto (JP)
Filed by SHIMADZU CORPORATION, Kyoto (JP)
Filed on Sep. 12, 2022, as Appl. No. 17/942,982.
Claims priority of provisional application 63/245,805, filed on Sep. 18, 2021.
Prior Publication US 2023/0088216 A1, Mar. 23, 2023
Int. Cl. G01N 30/38 (2006.01); B01D 15/14 (2006.01); B01D 15/18 (2006.01); B08B 9/032 (2006.01); G01N 30/22 (2006.01); G01N 30/02 (2006.01)
CPC G01N 30/38 (2013.01) [B01D 15/14 (2013.01); B01D 15/18 (2013.01); B08B 9/0325 (2013.01); G01N 30/22 (2013.01); B08B 2209/032 (2013.01); G01N 2030/027 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A liquid chromatograph comprising:
at least one mobile phase supply flow path for supplying a mobile phase, the at least one mobile phase supply flow path including an analysis mobile phase supply flow path for supplying an analysis mobile phase;
at least one cleaning solution supply flow path to supply a cleaning solution as liquid having a property different from that of the mobile phase;
an analysis flow path provided with a separation column for separating a component in a sample;
a sampling flow path provided, at a tip end thereof, with a sampling needle moving three-dimensionally and performing liquid suction from a tip end thereof;
a delivery flow path having an upper stream end to which both of the mobile phase supply flow path and the cleaning solution supply flow path are connected, the delivery flow path being provided for delivering toward the analysis flow path and/or the sampling flow path the mobile phase supplied from the mobile phase supply flow path and the cleaning solution supplied from the cleaning solution supply flow path,
a switcher including a high-pressure valve having an injection port connected to the sampling flow path by insertion of the tip end of the needle into the injection port and configured to switch a flow path configuration of the liquid chromatograph between a loading state in which the analysis mobile phase supply flow path and the analysis flow path are connected in a fluid manner without the sampling flow path and an injecting state in which the sampling flow path is interposed between the analysis mobile phase supply flow path and the analysis flow path when the tip end of the needle is inserted into the injection port; and
a controller configured to control operation of supplying the mobile phase through the mobile phase supply flow path, operation of supplying the cleaning solution through the cleaning solution supply flow path, operation of the needle, and operation of the switcher and execute, when a predetermined condition is satisfied, cleaning operation of delivering the mobile phase and the cleaning solution to the analysis flow path and/or the sampling flow path through the delivery flow path to temporally change a composition of liquid flowing in the analysis flow path and/or the sampling flow path;
wherein the controller is configured to
temporally change, by using a stepwise method or a gradient method, a flow rate of the mobile phase supplied from the mobile phase supply flow path to the delivery flow path and a flow rate of the cleaning solution supplied from the cleaning solution supply flow path to the delivery flow path, such that the composition is temporally changed of the liquid delivered to the analysis flow path and/or the sampling flow path, and
clean the analysis flow path and/or the sampling flow path by using the temporally changed composition of liquid.