Patent US595343A successfully refreshed from Google Patents.
Patent US4363633A successfully refreshed from Google Patents.
US4363633A
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US
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Reference liquid
Assignee: Radiometer AS
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Filing: 1980-06-24
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Granted: 1982-12-14
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Expires: 2000-06-24
Abstract
Abstract A reference liquid for calibration or quality control of instruments which determine ionized calcium and pH. The reference liquid contains both a particular calcium ion activity and a pH-buffer and can therefore be used for calibration of both the calcium-sensitive electrode and the pH-electrode in the instruments. The pH-buffer is a nitrogen-containing organic sulphonic acid and the salt of this acid, the acid having a pK in the range of 6.6-7.6. The reference liquid has an ionic strength of 0.15-0.17, a buffer capacity β in the range of 0.04-0.10 and is packed in glass ampoules.
Inventors
- 👤 Torben F. Christiansen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:39
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/4163; G01N27/4165; Y; Y10; Y10T; Y10T436/00; Y10T436/10; Y10T436/106664; Y10T436/108331; Y10T436/109163
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
116 words
A process for calibration or quality control of instruments adapted to determine ionized calcium and pH in physiological liquids and containing a calcium-sensitive electrode and a pH-electrode, comprising subjecting the calcium-sensitive electrode and the pH-electrode to calibration or quality control with a reference liquid which, at a particular temperature simulates the physiological liquid's calcium ion activity and which in addition contains a pH-buffer consisting of a nitrogen-containing organic sulphonic acid and the salt of this acid, the acid having a pK in the range of 6.6-7.6 at 37° C., the buffering capacity of the pH-buffer in the reference liquid being from about 0.04 to about 0.10, and the ionic strength of the reference liquid being 0.15-0.17.
Claim 2
Dependent Claim
116 words
A process for calibration or quality control of instruments adapted to determine ionized calcium and pH in physiological liquids and containing a calcium-sensitive electrode and a pH-electrode, comprising subjecting the calcium-sensitive electrode and the pH-electrode to calibration or quality control with a reference liquid which, at a particular temperature simulates the physiological liquid's calcium ion activity and which in addition contains a pH-buffer consisting of a nitrogen-containing organic sulphonic acid and the salt of this acid, the acid having a pK in the range of 6.6-7.6 at 37° C., the buffering capacity of the pH-buffer in the reference liquid being from about 0.04 to about 0.10, and the ionic strength of the reference liquid being 0.15-0.17.
Claim 3
Dependent Claim
31 words
A process as claimed in claim 1 wherein the nitrogen-containing organic sulphonic acid is an alkanesulphonic acid with a nitrogen-containing basic group attached to the alkane moiety via a nitrogen atom.
Claim 4
Dependent Claim
19 words
The process as claimed in claim 2 wherein the alkane moiety in the alkanesulphonic acid contains 2-3 carbon atoms.
Claim 5
Dependent Claim
44 words
The process as claimed in claim 3 wherein the alkane sulphonic acid is selected from the group consisting of 3-(N-morpholino)propane sulphonic acid (MOPS), piperazine-N,N'-bis(2-ethane sulphonic acid) (PIPES), N-(2-acetamido)-2-aminoethane sulphonic acid (ACES), N,N-bis(2-hydroxyethyl)-2-aminoethane sulphonic acid (BES), N-tris(hydroxymethyl)methyl-2-aminoethane sulphonic acid (TES), and N-2-hydroxyethylpiperazine-N-2-ethane sulphonic acid (HEPES).
Claim 6
Dependent Claim
21 words
The process as claimed in claim 1 wherein the buffer capacity β of the pH-buffer is in the range of 0.05-0.08.
References Cited (Backward Citations)
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Cited
US3941565A
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US3799885A
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US3932233A
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US4126575A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-13 | 1986-06-14 | 1986-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-13 | 1990-06-14 | 1990-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-13 | 1994-06-14 | 1994-12-14 | $7700.00 | Window Closed / Lapsed |