US4957009A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pushloop liquid sampling method
Assignee: Thermo Instrument Systems Inc
•
Filing: 1990-01-11
•
Granted: 1990-09-18
•
Expires: 2010-01-11
Abstract
Abstract A pushloop liquid sampling method is an improvement in the method of introducing liquid samples into test equipment (such as for liquid chromotography) via a six port valve. The method involves pulling the sample completely past the sample loop in the six port valve and then pushing the desired amount of sample back into the sample loop.
Inventors
- 👤 Andre Nohl
- 👤 Landy B. White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:24
CPC Classifications
G; G01; G01N; G01N35/00; G01N35/10; G01N35/1095; G01N35/1097; G01N30/00; G01N30/02; G01N30/04; G01N30/16; G01N30/20; Y; Y10; Y10T; Y10T436/00; Y10T436/25; Y10T436/2575
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
107 words
A method of transferring a liquid sample from a reservoir to an analytical column by means of a valve having a body and having at least two position comprising the steps of: drawing the sample from the reservoir through a needle; passing the sample from the needle through the valve in a first direction with the valve in a first position; switching the valve to a second position; passing only a portion of the sample into the valve in a second direction; and then injecting the portion of sample into the column; wherein at all times the needle is stationary relative to the body of the valve.
Claim 2
Independent Claim
107 words
A method of transferring a liquid sample from a reservoir to an analytical column by means of a valve having a body and having at least two position comprising the steps of: drawing the sample from the reservoir through a needle; passing the sample from the needle through the valve in a first direction with the valve in a first position; switching the valve to a second position; passing only a portion of the sample into the valve in a second direction; and then injecting the portion of sample into the column; wherein at all times the needle is stationary relative to the body of the valve.
Claim 3
Dependent Claim
24 words
The method of claim 1, wherein a metering device is used in passing the sample into the valve at least in the second direction.
Claim 4
Dependent Claim
12 words
The method of claim 2, wherein the metering device is a syringe.
Claim 5
Dependent Claim
34 words
The method of claim 2, further comprising the step of partially filling the metering device with a solvent so as to account for backlash in the metering device prior to the first mentioned step.
Claim 6
Dependent Claim
25 words
The method of claim 2, further comprising the step of taking up backlash in the metering device prior to the step of switching the valve.
Claim 7
Dependent Claim
38 words
The method of claim 2, wherein the valve includes a sample loop, and the first valve position disconnects the metering device from the sample loop, and the second valve position connects the metering device to the sample loop.
Claim 8
Dependent Claim
20 words
The method of claim 2, further comprising the step of preventing any of the sample from entering the metering device.
Claim 9
Dependent Claim
24 words
A method of claim 1, wherein the valve includes at least six ports and a needle does not extend into any of the ports.
Claim 10
Dependent Claim
12 words
The method of claim 8, wherein the valve includes a sample loop.
Claim 11
Dependent Claim
14 words
The method of claim 1, wherein the steps are under control of computer means.
Claim 12
Dependent Claim
27 words
The method of claim 1, further comprising the step of switching the valve to the first position after the step of passing the sample into the valve.
Claim 13
Dependent Claim
31 words
The method of claim 1, further comprising the step of passing the sample out of the valve after the step of passing the sample into the valve in the second direction.
Claim 14
Dependent Claim
54 words
The method of claim 1, further including the steps of: providing a metering device having a stroke for metering a particular volume for passing the sample through the valve; and wherein the portion of the sample injected into the column is an amount less than that metered by one stroke of the metering device.
References Cited (Backward Citations)
US2981092A
Cited
US3122168A
Cited
US3530721A
Cited
US3932065A
Cited
US3975946A
Cited
US3933165A
Cited
US4007626A
Cited
US3991055A
Cited
SU628421A1
Cited
US4068528A
Cited
US4620452A
Cited
US4722830A
Cited
JPH034336A
Cited
JPH086751A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-17 | 1994-03-19 | 1994-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-17 | 1998-03-19 | 1998-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-17 | 2002-03-19 | 2002-09-18 | $7700.00 | Window Closed / Lapsed |