Gas chromatograph

Patent metadata

Field	Value
Publication number	US-2020166484-A1
Application number	US-201816199385-A
Country	US
Kind code	A1
Filing date	Nov 26, 2018
Priority date	Nov 26, 2018
Publication date	May 28, 2020
Grant date	—

Abstract

A gas chromatograph, which may have a complex device configuration, capable of starting an analysis by replacing residual gas in a column with a carrier gas in starting up the gas chromatograph and by increasing the temperature of a column oven to an analytical initial temperature immediately after completion of the replacement.
Upon command to start a gas chromatograph, a control unit calculates the average linear velocity of a carrier gas using a formula based on information such as the inner diameter and the length of a column, the column head pressure and the column outlet pressure, and the type of carrier gas, which are set as analytical conditions, and, for example, based on a detected temperature of a column oven and further calculates gas replacement necessary time from the average linear velocity and the length of the column Based on the calculated time, a start time is determined.

First claim

What is claimed is:

1 . A gas chromatograph comprising:
a column, a column oven accommodating the column, a detector detecting a component from a sample having passed the column, a flow rate controller controlling a flow rate of a carrier gas supplied to the column, and a sample introduction unit provided to a head of the column and introducing the sample to the column on a stream of the carrier gas controlled by the flow rate controller, a) an information gathering unit configured to gather at least information relating to a column head pressure and a column outlet pressure, a length and an inner diameter of the column, a type of the carrier gas, and a temperature of the column oven; b) a time calculation unit configured to calculate a time necessary to replace gas in the column with the carrier gas fed to the column, in an starting up operation of the gas chromatograph or in a recovery operation of the gas chromatograph, which is an operation of recovery from a state in which at least temperature control on the column oven is stopped or the column oven is maintained at a predetermined temperature with no carrier gas supplied from the flow rate controller to the column to a regular standby state to conduct an analysis, at a timing to start the starting up operation or to start the recovery operation or at any timing prior to the timing, based on information gathered by the information gathering unit; and c) an analysis control unit configured to, in the starting up operation of the gas chromatograph or in the recovery operation of the gas chromatograph, permit temperature control with an increase in a temperature to be conducted on the column oven after a time calculated by the time calculation unit or the time plus a predetermined extra time has passed from a start of supplying the carrier gas from the flow rate controller to the column.

2 . The gas chromatograph of claim 1 , wherein at least in use of a plurality of juxtaposed columns together for an analysis, the time calculation unit calculates a time necessary to replace gas in the column on each of the columns, and the analysis control unit determines a timing to permit temperature control to be conducted on the column oven based on a longest time among the times of respective columns.

3 . The gas chromatograph of claim 1 , further comprising:
an input setting unit configured to be used by a user to input and set a standby time from a timing to start supplying carrier gas to a timing to start temperature control on the column oven, wherein the analysis control unit selects between a time calculated by the time calculation unit or the time plus a predetermined extra time and the standby time set using the input setting unit and determines a timing to permit temperature control to be conducted on the column oven based on the selected time.

4 . A gas chromatograph including a column, a column oven accommodating the column, a detector detecting a component from a sample having passed the column, a flow rate controller controlling a flow rate of a carrier gas supplied to the column, and a sample introduction unit provided to a head of the column and introducing the sample to the column on a stream of the carrier gas controlled by the flow rate controller, the gas chromatograph comprising:
a) an information gathering unit configured to gather at least information relating to a column outlet pressure, a length and an inner diameter of the column, a type of the carrier gas, and a temperature of the column oven; b) a head pressure calculation unit configured to calculate a column head pressure at which such an average linear velocity of the carrier gas is achieved that allows a time necessary to replace gas in the column with the carrier gas fed to the column to fall below a target value, in a starting operation of the gas chromatograph or in a recovery operation of the gas chromatograph, which is an operation of recovery from a state in which at least temperature control on the column oven is stopped or the column oven is maintained at a predetermined temperature with no carrier gas supplied from the flow rate controller to the column to a regular standby state to conduct an analysis, at a timing to start the starting operation or to start the recovery operation or at any timing prior to the timing, based on information gathered by the information gathering unit; and c) an analysis control unit configured to, in the starting operation of the gas chromatograph or in the recovery operation of the gas chromatograph, permit temperature control with an increase in a temperature to be conducted on the column oven after the target value or the target value plus a predetermined extra time has passed from a start of supplying the carrier gas from the flow rate controller to the column under setting of the column head pressure calculated by the head pressure calculation unit.

5 . A gas chromatograph comprising:
a column, a column oven accommodating the column, a detector detecting a component from a sample having passed the column, a flow rate controller controlling a flow rate of a carrier gas supplied to the column, and a sample introduction unit provided to a head of the column and introducing the sample to the column on a stream of the carrier gas controlled by the flow rate controller, a) an information gathering unit configured to gather at least information relating to a column head pressure and a column outlet pressure, a length and an inner diameter of the column, and a type of the carrier gas; b) a temperature detection unit configured to detect a temperature inside the column oven or a temperature around the column oven; c) an replacement information calculation unit configured to, in a starting up operation of the gas chromatograph or in a recovery operation of the gas chromatograph, which is an operation of recovery from a state in which at least temperature control on the column oven is stopped with no carrier gas supplied from the flow rate controller to the column, to a regular standby state to conduct an analysis, calculate a length of a part of the column in which gas in the column has been replaced by the carrier gas fed to the column based on information gathered by the information gathering unit and a temperature repeatedly detected by the temperature detection unit over time, after a start of supplying the carrier gas from the flow rate controller to the column; and d) an analysis control unit configured to determine whether gas in the column has been adequately replaced, based on a length of the part of the column calculated by the replacement information calculation unit and permit temperature control with an increase in a temperature to be conducted on the column oven after determination that the gas has been adequately replaced.

6 . The gas chromatograph of claim 2 , further comprising:
an input setting unit configured to be used by a user to input and set a standby time from a timing to start supplying carrier gas to a timing to start temperature control on the column oven, wherein the analysis control unit selects between a time calculated by the time calculation unit or the time plus a predetermined extra time and the standby time set using the input setting unit and determines a timing to permit temperature control to be conducted on the column oven based on the selected time.

Assignees

• Shimadzu Corp

Inventors

• Masuda Shingo

Classifications

• G01N2030/3084

  ovens · CPC title

• G01N30/64

  Electrical detectors · CPC title

• G01N30/32 Primary

  of pressure or speed (G01N30/36 takes precedence) · CPC title

• G01N30/466

  with separation columns in parallel · CPC title

• G01N2030/025

  Gas chromatography · CPC title