US3668834A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sample injection in gas chromatography
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1970-07-31
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Granted: 1972-06-13
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Expires: 1990-07-31
Abstract
Abstract Sample injection in gas chromatography is accomplished by passing a sample stream separate from the carrier gas stream and diverting it into the carrier gas stream through an unrestricted limb by adjusting the relative pressures of the two streams.
Inventors
- 👤 David Robert Deans
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:52
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/04; G01N30/16; G01N30/26; G01N30/38; G01N30/46; G01N30/461
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
63 words
Apparatus for supplying a stream of carrier gas to a chromatographic column as claimed in claim 1 in which the conduit is fed by a flow controller and the means for diverting the sample from the conduit through the sample injection limb to the junction comprises a restriction to gas flow in the vent from the conduit, and means for closing the vent.
Claim 2
Dependent Claim
69 words
Apparatus as claimed in claim 1 in which the conduit is fed by a pressure controller and the means for diverting sample from the conduit through the sample injection limb to the junction comprises a restriction to gas flow in the vent of the conduit, means for closing the vent and a restriction to gas flow on the output side of the pressure controller admitting gas to the conduit.
Claim 3
Dependent Claim
71 words
Apparatus as claimed in claim 1 in which the conduit is fed by a pressure controller and the means for diverting sample from the conduit through the sample injection limb to the junction comprises a restriction to gas flow in the vent of the conduit, a restriction to gas flow on the output side of the pressure controller admitting gas to the conduit, and means for closing tHe carrier gas limb.
Claim 4
Dependent Claim
29 words
Apparatus as claimed in claim 1 in which means is provided for introducing a sample into a continuous gas stream passing through the conduit before it reaches the junction.
Claim 5
Dependent Claim
29 words
Apparatus as claimed in claim 5 in which means is provided to pass sample through the sample injection limb at a pre-set time after the introduction of the sample.
Claim 6
Dependent Claim
20 words
Apparatus as claimed in claim 6 in which the timing means injects the sample for a pre-set period of time.
Claim 7
Dependent Claim
26 words
Apparatus as claimed in claim 1 in which both controllers are pressure controllers and they are linked to a common means for controlling their pressure setting.
Claim 8
Dependent Claim
20 words
Apparatus as claimed in claim 1 in which the conduit is provided with a second vent controlled by a restriction.
Claim 9
Independent Claim
62 words
A method of injecting sample into a chromatographic column which comprises passing a continuous stream of carrier gas through the column, passing a separate stream of a fluid to be sampled and diverting parts of the separate stream of fluid to be sampled into the carrier gas stream through an unrestricted sample injection limb by varying a pressure difference across the limb.
Claim 10
Dependent Claim
112 words
Chromatographic apparatus comprising: a chromatographic column; a first carrier gas controller for receiving carrier gas from a source thereof; a first conduit extending from the first gas controller to the column; a second carrier gas controller for receiving carrier gas from a source thereof; a second conduit extending from the second gas controller to a vent; means for adding a sample to said second conduit; an unrestricted sample line connecting said second conduit with said first conduit; and adjustable restricting means in one of said conduits for diverting flow from said second conduit through said sample line into said first conduit by creating a pressure difference between the first and second conduits.
Claim 11
Independent Claim
87 words
A method of injecting sample into a chromatographic column which comprises: effecting a continuous stream of carrier gas to and through the column; effecting a separate stream of carrier gas; providing a connection between the streams; adding fluid to be sampled to the separate stream carrier gas; and then diverting parts of the separate stream through the connection into the continuous stream by varying the pressure in one of the streams so as to effect a negative pressure differential between the continuous stream and the separate stream.
References Cited (Backward Citations)
US3030798A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-13 | 1975-12-13 | 1976-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-13 | 1979-12-13 | 1980-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-13 | 1983-12-13 | 1984-06-13 | $7700.00 | Window Closed / Lapsed |