EP0406757A2
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Method for chromatographic separation
Assignee: VTT Technical Research Centre of Finland
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Filing: 1990-07-02
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Granted: —
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Expires: 2010-07-02
Abstract
Abstract The disclosure concerns a procedure and an apparatus for chromatographic separation. According to the invention, the separation between a stationary, preferably liquid phase in a column and a gaseous mobile phase passed through it is performed in two stages by taking the sample under analysis to a first column (1) for rough separation of the compounds contained in it and cutting off the rough fraction separated from the sample by said column into a second column (2) for a second separation stage. The essential feature of the invention is that one or more reference compounds, i.e. retention index standards, are introduced into the first column (1) simultaneously with the sample, said reference compounds being so chosen that the retention time of at least one of them is shorter than that of the fraction to be separated from the sample, that the separation taking place in the first column is monitored using a detector (14), and that after the detector has detected one or more of the reference compounds said fraction is cut off into the second column (2) at an instant determined on the basis of the retention times of the detected reference compounds or other retention parameters calculated from the retention times. The procedure enables the cutting-off to be performed at the right moment regardless of the change in retention times caused by the soiling of the columns.
Inventors
- 👤 Kimmo Himberg
- 👤 Erkki Sippola
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 03:45
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/26; G01N30/38; G01N30/46; G01N30/461; G01N30/04; G01N30/06; G01N2030/382; G01N2030/383; G01N30/62; G01N2030/621; G01N2030/625
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
184 words
Procedure for chromatographic separation, whereby the separation between a stationary phase in a column and a mobile phase passed through it is performed in two stages by taking the sample under treatment to a first column (1) for rough separation of the compounds contained in the sample and passing the rough fraction separated from the sample by said column into a second column (2) for a second separation stage, characterized in that one or more reference compounds are introduced into the first column (1) simultaneously with the sample, said reference compounds being so chosen that the retention time of at least one of them is shorter than that of the fraction to be separated from the sample, that the separation taking place in the first column is monitored using a detector (14), and that after the detector has detected one or more of the reference compounds said fraction is transferred to the second column (2) at an instant determined on the basis of the retention times of the detected reference compounds or on the basis of other retention parameters calculated from the retention times.
Claim 2
Dependent Claim
184 words
Procedure for chromatographic separation, whereby the separation between a stationary phase in a column and a mobile phase passed through it is performed in two stages by taking the sample under treatment to a first column (1) for rough separation of the compounds contained in the sample and passing the rough fraction separated from the sample by said column into a second column (2) for a second separation stage, characterized in that one or more reference compounds are introduced into the first column (1) simultaneously with the sample, said reference compounds being so chosen that the retention time of at least one of them is shorter than that of the fraction to be separated from the sample, that the separation taking place in the first column is monitored using a detector (14), and that after the detector has detected one or more of the reference compounds said fraction is transferred to the second column (2) at an instant determined on the basis of the retention times of the detected reference compounds or on the basis of other retention parameters calculated from the retention times.
Claim 3
Dependent Claim
34 words
Procedure according to claim 1, characterized in that the stationary phases in the first and second columns (1, 2) are different substances, whereas the mobile phase in both columns consists of the same substance.
Claim 4
Dependent Claim
21 words
Procedure according to claim 2, characterized in that the stationary phases are liquids and that the mobile phase is a gas.
Claim 5
Dependent Claim
21 words
Procedure according to any one of the preceding claims, characterized in that the reference compounds comprise a homologous series of compounds.
Claim 6
Dependent Claim
42 words
Procedure according to claim 4, characterized in that the fraction separated by the first column (1) is transferred into the second column (2) after at least two of the reference compounds of the homologous series have been detected by the detector (14).
Claim 7
Dependent Claim
151 words
Apparatus for chromatographic separation, comprisisng two successive columns (1, 2) each of which contains filling material constituting the stationary phase, supply and discharge ducts (3, 6, 8) connected to the first column (1) for passing the mobile phase and the sample under analysis through the column for rough separation of the compounds contained in the sample, and an inter-column connecting duct (6, 9) for transferring the rough fraction separated from the sample by the first column into the second column (2) for a second separation stage, characterized in that a detector (14) is connected between the columns (1,2), allowing the separation taking place in the first column (1) to be so monitored as to permit the transfer of said fraction into the second column (2) to be based during analysis on the reference compounds detected by the detector, said reference compounds being introduced into the first column together with the sample.
Claim 8
Dependent Claim
151 words
Apparatus for chromatographic separation, comprisisng two successive columns (1, 2) each of which contains filling material constituting the stationary phase, supply and discharge ducts (3, 6, 8) connected to the first column (1) for passing the mobile phase and the sample under analysis through the column for rough separation of the compounds contained in the sample, and an inter-column connecting duct (6, 9) for transferring the rough fraction separated from the sample by the first column into the second column (2) for a second separation stage, characterized in that a detector (14) is connected between the columns (1,2), allowing the separation taking place in the first column (1) to be so monitored as to permit the transfer of said fraction into the second column (2) to be based during analysis on the reference compounds detected by the detector, said reference compounds being introduced into the first column together with the sample.
Claim 9
Dependent Claim
24 words
Apparatus according to claim 6, characterized in that the filling materials contained by the columns (1, 2) are mutually differing liquids, such as polysiloxanes.
Claim 10
Dependent Claim
26 words
Apparatus according to claim 6 or 7, characterized in that the detector (14) is a flame ionization detector, an electron capture detector or a nitrogen-phosphorus detector.
Claim 11
Dependent Claim
72 words
Apparatus according to any one of claims 6-8, characterized in that the discharge duct (8) of the first column (1) and the connecting duct (9) between the columns (1, 2) branch off from each other and are provided with valve means (12, 13) enabling the flow discharged from the first column to be directed into either one of said ducts on the basis of a detection signal provided by the detector (14).
Claim 12
Dependent Claim
53 words
Apparatus according to claim 9, characterized in that the connecting duct (9) between the columns (1, 2) communicates with a feed duct (11) through which a substance constituting the mobile phase can be supplied into the second column (2) and also, via the connecting duct, into the discharge duct (8) of column (1).
References Cited (Backward Citations)
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