WO1983003006A1 - Method for measuring ionic concentration utilizing an ion-sensing electrode - Google Patents
Method for measuring ionic concentration utilizing an ion-sensing electrode Download PDFInfo
- Publication number
- WO1983003006A1 WO1983003006A1 PCT/US1982/001750 US8201750W WO8303006A1 WO 1983003006 A1 WO1983003006 A1 WO 1983003006A1 US 8201750 W US8201750 W US 8201750W WO 8303006 A1 WO8303006 A1 WO 8303006A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- membrane
- electrode
- ion
- sample
- electrolyte
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/483—Physical analysis of biological material
- G01N33/487—Physical analysis of biological material of liquid biological material
- G01N33/49—Blood
- G01N33/4925—Blood measuring blood gas content, e.g. O2, CO2, HCO3
Definitions
- the invention relates to the field of chemical analyzers. More particularly, the invention relates to the field of chemical analyzers using electrochemical measuring systems. In still greater particularity, the invention relates to the field of chemical analyzers utilizing ion-sensing electrodes. By way of further characterization, but not by way of limitation thereto, the invention is a method for sensing ion concentration utilizing an ion-sensing electrode having a gas-permeable ion-impermeable membrane in which an electrolyte solution is pumped between the electrode and the membrane.
- the carbon dioxide-sensing element includes a renewable electrolyte disposed between a gas-permeable membrane and an ion-sensitive electrode. Gas diffusing through the membrane from a sample substance in a cup on the opposite side of the membrane from the electrode causes a reaction in the renewable electrolyte which is sensed by the ion electrode. The electrical output of this electrode, either as a rate or equilibrium condi ⁇ tion, is proportional to the gas diffusing through the membrane.
- the senor is located in communication with the cup containing a substrate with zero partial pressure or partial pressure of the gas to be detected equal to that in the renewable electrolyte, both, for instance, being in equilibrium to the atmosphere.
- the gas of interest is released, diffusing through the membrane, and initiating the reaction in the renewable electrolyte.
- Several factors may influence the rate of this initiation, such as the reproducibility and the time required for introducing the sample, the quality of stirring employed for mixing the sample with the substrate, and the time interval between renewing the electrolyte and introducing the sample.
- the invention is a method for measuring ionic concentration in a flow cell apparatus.
- a gas produced by the ion diffuses through a membrane to react with an electrolyte solution.
- the change in the electrolyte solution is measured by an ion-sensing electrode.
- the sample solution is pumped through the flow cell and stopped at a point adjacent the sensor.
- the method includes pumping the electrolyte solution between the
- Fig. 1 illustrates an ion-sensing electrode used with the present invention
- Fig. 2 is a diagram of the apparatus for measuring ionic concentrations utilizing the present invention. Description of the Preferred Embodiment
- Fig. 1 illustrates an ion-sensing electrode and is the same as Fig. 4 of U.S. Patent 4,003,705.
- elements essential to this application will be referred to and have been renumbered for ease of illustration.
- the reference numerals from U.S. Patent No. 4,003,705 will be placed in parentheses behind the new reference numerals to aid in understanding the operation of the apparatus. That is, a complete understanding of the operation of the apparatus of Fig. 1 may be had by reference to the description contained in U.S. Patent No. 4,003,705.
- a sensing element 11 includes an ion-sensing electrode 12 (92) and an ion-permeable membrane 13 (108).
- a passage 14 (114) and a passage 15 (116) allow an electrolyte solution to be pumped between electrode 12 and membrane 13.
- a flow cell 16 contains the sample substance premixed with acid to produce sub ⁇ stance 17 which is to be measured. Electrode 12 and membrane 13 are positioned adjacent flow cell 16. Pas ⁇ sages 14 and 15 allow an electrolyte solution 18 to be pumped between electrode 12 and membrane 13. The flow
- premixed sample substance 17 is pumped into flow cell 16 and stopped adjacent member 13 such that sample substance 17 contacts membrane 13.
- Carbon dioxide (C0 2 ) gas, released from sample substance 17, diffuses through membrane 13 to react with the electrolyte solution 18 as described in the incorporated U.S. patents.
- the partial pressure of carbon dioxide in the reference solution in flow cell 16 before the sample substance 17 is pumped into flow cell 16 is not equal to that of the electrolyte solution 18. That is, unlike the situation described in the above referenced U.S. Patents, there is a continual diffusion of C0 2 gas through membrane 13.
- the quantity of CO- gas released by the internal reference solution is known.
- the method may be employed with any sensing element utilizing an electrode, a membrane, and an electrolyte solution therebetween.
- the method may also be employed to obtain more than one reading from a given sample by pumping and stopping the renewable electrolyte again with the sample remaining in place.
- the method could also be used to monitor a continually flowing stream where the concentration of the gas or ion of interest may be continually changing. A gradient could thus be generated showing the change over time.
Abstract
A method for measuring the concentration of a gas. The method includes circulating an electrolyte solution (18) between an electrode (12) and a gas-permeable, ion-impermeable membrane (13) spaced from said electrode. The ionic concentration is measured after the circulating electrolyte has been stopped.
Description
METHOD FOR MEASURING IONIC CONCENTRATION UTILIZING AN ION-SENSING ELECTRODE
Background of the Invention Field of the Invention The invention relates to the field of chemical analyzers. More particularly, the invention relates to the field of chemical analyzers using electrochemical measuring systems. In still greater particularity, the invention relates to the field of chemical analyzers utilizing ion-sensing electrodes. By way of further characterization, but not by way of limitation thereto, the invention is a method for sensing ion concentration utilizing an ion-sensing electrode having a gas-permeable ion-impermeable membrane in which an electrolyte solution is pumped between the electrode and the membrane. Description of the Related Art
U.S. Patents No. 4,003,705 and 4,170,523 issued to E. E. Buzza et al. and assigned to the as- signee of the present invention describe an electro¬ chemical analysis apparatus for measuring both chloride and carbon dioxide in blood. As disclosed in those patents, the carbon dioxide-sensing element includes a renewable electrolyte disposed between a gas-permeable membrane and an ion-sensitive electrode. Gas diffusing through the membrane from a sample substance in a cup on the opposite side of the membrane from the electrode causes a reaction in the renewable electrolyte which is sensed by the ion electrode. The electrical output of this electrode, either as a rate or equilibrium condi¬ tion, is proportional to the gas diffusing through the membrane.
In the above-mentioned patents, the sensor is located in communication with the cup containing a substrate with zero partial pressure or partial pressure
of the gas to be detected equal to that in the renewable electrolyte, both, for instance, being in equilibrium to the atmosphere. When the sample is introduced into the substrate, the gas of interest is released, diffusing through the membrane, and initiating the reaction in the renewable electrolyte. Several factors may influence the rate of this initiation, such as the reproducibility and the time required for introducing the sample, the quality of stirring employed for mixing the sample with the substrate, and the time interval between renewing the electrolyte and introducing the sample.
In a situation, such as a stopped flow-through system, which requires a high throughput, initiation of the rate reaction by the previous method is not possible. The sample liquid must be premixed with acid, thereby releasing the ion of interest before entering the flow cell where the sensor is located. Thus, the addition of sample is not the event which initiates the rate reaction. Also, the premixed sample is purged by a bicarbonate solution of fixed concentration which is also premixed with acid to act as an internal reference. At no time, therefore, is there is a solution of zero or partial pressure of CO? equal to that of the renewable electrolyte in contact with the outside of the membrane. In this system there is no stirring required in the flow cell during the measuring interval because the sample and acid have been premixed.
Summary of the Invention The invention is a method for measuring ionic concentration in a flow cell apparatus. A gas produced by the ion diffuses through a membrane to react with an electrolyte solution. The change in the electrolyte solution is measured by an ion-sensing electrode. The sample solution is pumped through the flow cell and stopped at a point adjacent the sensor. The method includes pumping the electrolyte solution between the
membrane and the electrode until the measurement is to take place. At this point, the electrolyte pumping is stopped and the ionic concentration is measured. Brief Description of the Drawings Fig. 1 illustrates an ion-sensing electrode used with the present invention; and
Fig. 2 is a diagram of the apparatus for measuring ionic concentrations utilizing the present invention. Description of the Preferred Embodiment
The above-mentioned U.S. Patents No. 4,003,705 and 4,170,523 are incorporated herein by reference and made a part of this specification. Fig. 1 illustrates an ion-sensing electrode and is the same as Fig. 4 of U.S. Patent 4,003,705. Referring to Fig. 1, elements essential to this application will be referred to and have been renumbered for ease of illustration. However, the reference numerals from U.S. Patent No. 4,003,705 will be placed in parentheses behind the new reference numerals to aid in understanding the operation of the apparatus. That is, a complete understanding of the operation of the apparatus of Fig. 1 may be had by reference to the description contained in U.S. Patent No. 4,003,705. Referring to Fig. 1, a sensing element 11 (30) includes an ion-sensing electrode 12 (92) and an ion-permeable membrane 13 (108). A passage 14 (114) and a passage 15 (116) allow an electrolyte solution to be pumped between electrode 12 and membrane 13. Referring to Fig. 2, a flow cell 16 contains the sample substance premixed with acid to produce sub¬ stance 17 which is to be measured. Electrode 12 and membrane 13 are positioned adjacent flow cell 16. Pas¬ sages 14 and 15 allow an electrolyte solution 18 to be pumped between electrode 12 and membrane 13. The flow
OMPI
WIPO
of electrolyte 18 is controlled by a valve 19. Sample substance 17 contacts membrane 13. Mode of Operation
Referring to Fig. 2, premixed sample substance 17 is pumped into flow cell 16 and stopped adjacent member 13 such that sample substance 17 contacts membrane 13. Carbon dioxide (C02) gas, released from sample substance 17, diffuses through membrane 13 to react with the electrolyte solution 18 as described in the incorporated U.S. patents. The partial pressure of carbon dioxide in the reference solution in flow cell 16 before the sample substance 17 is pumped into flow cell 16 is not equal to that of the electrolyte solution 18. That is, unlike the situation described in the above referenced U.S. Patents, there is a continual diffusion of C02 gas through membrane 13. The quantity of CO- gas released by the internal reference solution is known. Erroneous measurements of the carbon dioxide gas would result if a measurement were immediately taken upon stopping sample substance 17 adjacent membrane 13. That is, the carbon dioxide released from the reference solution is constantly being measured by the electrode and is different from the amount of carbon dioxide released by the sample substance. In order to overcome the above problem, after the premixed sample is in place electrolyte solution is pumped between electrode 12 and membrane 13 at a rate sufficient to remove the carbon dioxide gas faster than it is diffusing through the membrane. The rate of carbon dioxide diffusion is very slow. If the flow of electrolyte solution 18 is suddenly stopped, preferably by means of valve 19, the reaction of the gas diffusing through the membrane with the electrolyte solution 18 is initiated reproducibly and the rate of reaction is directly proportional to the concentration of carbon dioxide gas. Thus, a measurement may be taken almost
immediately upon stopping of the pumping of electrolyte solution 18. In practice, measurements have been taken in as short a time as five seconds.
While the invention has been disclosed with respect to a preferred embodiment thereof, it is not to be so limited as changes and modifications may occur which are within the full intended scope of the inven¬ tion as defined by the appended claims. For example, while the invention has been disclosed with respect to a system for measuring carbon dioxide gas as the substance of interest, the method may be employed with any sensing element utilizing an electrode, a membrane, and an electrolyte solution therebetween. The method may also be employed to obtain more than one reading from a given sample by pumping and stopping the renewable electrolyte again with the sample remaining in place. The method could also be used to monitor a continually flowing stream where the concentration of the gas or ion of interest may be continually changing. A gradient could thus be generated showing the change over time.
Claims
1. A method for measuring the concentration of a substance in a sample liquid, said method utilizing an ion-sensing electrode including a permeable membrane spaced from said electrode, said space between said membrane and said electrode containing an electrolyte solution, said method comprising the steps of: contacting said permeable membrane with said sample liguid; circulating said electrolyte solution through said space at a rate greater than said substance dif¬ fuses through said membrane; stopping said circulating electrolyte solu¬ tion; and measuring said concentration. c
2. Method of claim 1 wherein said substance includes carbon dioxide.
3. Method of claim* 1 wherein said electrolyte includes a bicarbonate ion.
4. Method of claim 1 wherein said electrode includes a pH electrode.
5. Method of claim 1 wherein said step of con¬ tacting includes stopping said sample substance adjacent said membrane.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE8383900384T DE3275238D1 (en) | 1982-02-22 | 1982-12-13 | Method for measuring ionic concentration utilizing an ion-sensing electrode |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/350,696 US4490234A (en) | 1982-02-22 | 1982-02-22 | Method for measuring ionic concentration utilizing an ion-sensing electrode |
US350,696820222 | 1982-02-22 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1983003006A1 true WO1983003006A1 (en) | 1983-09-01 |
Family
ID=23377811
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1982/001750 WO1983003006A1 (en) | 1982-02-22 | 1982-12-13 | Method for measuring ionic concentration utilizing an ion-sensing electrode |
Country Status (5)
Country | Link |
---|---|
US (1) | US4490234A (en) |
EP (1) | EP0102958B1 (en) |
CA (1) | CA1191898A (en) |
DE (1) | DE3275238D1 (en) |
WO (1) | WO1983003006A1 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1985002017A1 (en) * | 1983-11-03 | 1985-05-09 | Sven Olof Enfors | Sensor for chemical analysis |
WO1986007150A1 (en) * | 1985-05-21 | 1986-12-04 | Brian John Bellhouse | Apparatus for testing liquids |
GB2208707A (en) * | 1987-07-31 | 1989-04-12 | Sieger Ltd | Gas absorbing cell for gas analyser |
EP0354604A2 (en) * | 1988-07-08 | 1990-02-14 | INSTRUMENTATION LABORATORY S.p.A. | System for measuring the partial pressure of carbon dioxide in liquid samples, particularly in biological samples |
EP0475534A2 (en) * | 1990-09-14 | 1992-03-18 | INSTRUMENTATION LABORATORY S.r.l. | Process and apparatus for the electrochemical determination of oxigen in a blood gas analyzer |
WO1999030144A1 (en) * | 1997-12-11 | 1999-06-17 | The Victoria University Of Manchester | Sensor devices and analytical method |
Families Citing this family (20)
Publication number | Priority date | Publication date | Assignee | Title |
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DE3517131C1 (en) * | 1985-05-11 | 1986-11-13 | Eppendorf Gerätebau Netheler + Hinz GmbH, 2000 Hamburg | Method for measuring the potential difference between a sample liquid and a reference electrolyte and device for measuring the ion concentration in the sample liquid |
US4888998A (en) * | 1986-07-11 | 1989-12-26 | Beckman Instruments, Inc. | Sample handling system |
FI80800C (en) * | 1986-10-03 | 1990-07-10 | Kone Oy | A method for determining the total carbonate content, especially in a biological liquid |
AU600581B2 (en) * | 1987-05-15 | 1990-08-16 | Beckman Instruments, Inc. | Flow cell |
JP2690053B2 (en) * | 1988-01-08 | 1997-12-10 | マルハ株式会社 | Biosensor |
US4917776A (en) * | 1989-02-09 | 1990-04-17 | Larry Taylor | Flow through voltammetric analyzer and method using deoxygenator |
US5132233A (en) * | 1989-03-13 | 1992-07-21 | Beckman Instruments, Inc. | Sample injection cell |
US5130095A (en) * | 1989-03-13 | 1992-07-14 | Beckman Instruments, Inc. | Automatic chemistry analyzer |
US5130010A (en) * | 1989-03-13 | 1992-07-14 | Beckman Instruments, Inc. | Salt bridge for analytical chemistry system |
US5223222A (en) * | 1989-03-13 | 1993-06-29 | Beckman Instruments, Inc. | Automatic chemistry analyzer |
US5213762A (en) * | 1989-03-13 | 1993-05-25 | Beckman Instruments, Inc. | Automatic chemistry analyzer |
IT1244609B (en) * | 1990-09-14 | 1994-08-08 | Instrumentation Lab Spa | PROCEDURE AND EQUIPMENT FOR THE ELECTROCHEMICAL DETERMINATION OF GASEOUS OR VOLATILE SPECIES WITH PARTICULAR REFERENCE TO BLOOD-LEVELING SYSTEMS. |
GB9120144D0 (en) * | 1991-09-20 | 1991-11-06 | Imperial College | A dialysis electrode device |
DK2336274T3 (en) | 1999-04-07 | 2013-09-30 | Ivanhoe Htl Petroleum Ltd | Rapid heat processing of heavy oil raw materials |
EP1130393A3 (en) | 2000-02-03 | 2001-11-28 | Nihon Kohden Corporation | Gas sensor and gas sensor system |
CA2422534C (en) | 2000-09-18 | 2012-05-22 | Ensyn Group Inc. | Products produced from rapid thermal processing of heavy hydrocarbon feedstocks |
GB2397651B (en) * | 2003-01-15 | 2005-08-24 | Schlumberger Holdings | Methods and apparatus for the measurement of hydrogen sulphide and thiols in fluids |
US8758593B2 (en) * | 2004-01-08 | 2014-06-24 | Schlumberger Technology Corporation | Electrochemical sensor |
PE20140205A1 (en) | 2010-12-30 | 2014-03-08 | Ivanhoe Energy Inc | METHOD, SYSTEM AND APPARATUS FOR SEPARATION IN THE PROCESSING OF RAW MATERIALS |
US9707532B1 (en) | 2013-03-04 | 2017-07-18 | Ivanhoe Htl Petroleum Ltd. | HTL reactor geometry |
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US3505195A (en) * | 1965-12-29 | 1970-04-07 | Radiometer As | Electrode system for electro-chemical measurements in solutions |
US3997420A (en) * | 1971-03-18 | 1976-12-14 | Beckman Instruments, Inc. | Automatic analyzer |
US4003705A (en) * | 1975-06-12 | 1977-01-18 | Beckman Instruments, Inc. | Analysis apparatus and method of measuring rate of change of electrolyte pH |
US4149949A (en) * | 1978-07-06 | 1979-04-17 | Beckman Instruments, Inc. | Electrochemical analysis apparatus employing single ion measuring sensor |
US4170523A (en) * | 1976-11-04 | 1979-10-09 | Beckman Instruments, Inc. | Method for checking isolation between titration and electrochemical measuring systems of a chemical analyzer |
US4172770A (en) * | 1978-03-27 | 1979-10-30 | Technicon Instruments Corporation | Flow-through electrochemical system analytical method |
US4209300A (en) * | 1978-09-25 | 1980-06-24 | The United States Of America As Represented By The Department Of Health, Education And Welfare | Hemoglobin-oxygen equilibrium curve analyzer |
-
1982
- 1982-02-22 US US06/350,696 patent/US4490234A/en not_active Expired - Fee Related
- 1982-12-13 WO PCT/US1982/001750 patent/WO1983003006A1/en active IP Right Grant
- 1982-12-13 DE DE8383900384T patent/DE3275238D1/en not_active Expired
- 1982-12-13 EP EP83900384A patent/EP0102958B1/en not_active Expired
-
1983
- 1983-01-19 CA CA000419752A patent/CA1191898A/en not_active Expired
Patent Citations (7)
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US3505195A (en) * | 1965-12-29 | 1970-04-07 | Radiometer As | Electrode system for electro-chemical measurements in solutions |
US3997420A (en) * | 1971-03-18 | 1976-12-14 | Beckman Instruments, Inc. | Automatic analyzer |
US4003705A (en) * | 1975-06-12 | 1977-01-18 | Beckman Instruments, Inc. | Analysis apparatus and method of measuring rate of change of electrolyte pH |
US4170523A (en) * | 1976-11-04 | 1979-10-09 | Beckman Instruments, Inc. | Method for checking isolation between titration and electrochemical measuring systems of a chemical analyzer |
US4172770A (en) * | 1978-03-27 | 1979-10-30 | Technicon Instruments Corporation | Flow-through electrochemical system analytical method |
US4149949A (en) * | 1978-07-06 | 1979-04-17 | Beckman Instruments, Inc. | Electrochemical analysis apparatus employing single ion measuring sensor |
US4209300A (en) * | 1978-09-25 | 1980-06-24 | The United States Of America As Represented By The Department Of Health, Education And Welfare | Hemoglobin-oxygen equilibrium curve analyzer |
Non-Patent Citations (1)
Title |
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See also references of EP0102958A4 * |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1985002017A1 (en) * | 1983-11-03 | 1985-05-09 | Sven Olof Enfors | Sensor for chemical analysis |
WO1986007150A1 (en) * | 1985-05-21 | 1986-12-04 | Brian John Bellhouse | Apparatus for testing liquids |
US4844097A (en) * | 1985-05-21 | 1989-07-04 | Bellhouse Technology Limited | Apparatus and method for testing liquids |
GB2208707A (en) * | 1987-07-31 | 1989-04-12 | Sieger Ltd | Gas absorbing cell for gas analyser |
GB2208707B (en) * | 1987-07-31 | 1991-09-18 | Sieger Ltd | Gas analyser |
EP0354604A2 (en) * | 1988-07-08 | 1990-02-14 | INSTRUMENTATION LABORATORY S.p.A. | System for measuring the partial pressure of carbon dioxide in liquid samples, particularly in biological samples |
EP0354604A3 (en) * | 1988-07-08 | 1990-08-01 | INSTRUMENTATION LABORATORY S.p.A. | System for measuring the partial pressure of carbon dioxide in liquid samples, particularly in biological samples |
EP0475534A2 (en) * | 1990-09-14 | 1992-03-18 | INSTRUMENTATION LABORATORY S.r.l. | Process and apparatus for the electrochemical determination of oxigen in a blood gas analyzer |
EP0475534A3 (en) * | 1990-09-14 | 1992-07-22 | Instrumentation Laboratory S.R.L. | Process and apparatus for the electrochemical determination of oxigen in a blood gas analyzer |
WO1999030144A1 (en) * | 1997-12-11 | 1999-06-17 | The Victoria University Of Manchester | Sensor devices and analytical method |
Also Published As
Publication number | Publication date |
---|---|
DE3275238D1 (en) | 1987-02-26 |
EP0102958A4 (en) | 1984-06-29 |
EP0102958A1 (en) | 1984-03-21 |
EP0102958B1 (en) | 1987-01-21 |
US4490234A (en) | 1984-12-25 |
CA1191898A (en) | 1985-08-13 |
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