CA1220522A - Electrochemical sensing of carbon monoxide - Google Patents
Electrochemical sensing of carbon monoxideInfo
- Publication number
- CA1220522A CA1220522A CA000469013A CA469013A CA1220522A CA 1220522 A CA1220522 A CA 1220522A CA 000469013 A CA000469013 A CA 000469013A CA 469013 A CA469013 A CA 469013A CA 1220522 A CA1220522 A CA 1220522A
- Authority
- CA
- Canada
- Prior art keywords
- solution
- electrode
- electrolyte
- amount
- solvent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 title claims abstract description 21
- 229910002091 carbon monoxide Inorganic materials 0.000 title claims abstract description 21
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 27
- MHCFAGZWMAWTNR-UHFFFAOYSA-M lithium perchlorate Chemical compound [Li+].[O-]Cl(=O)(=O)=O MHCFAGZWMAWTNR-UHFFFAOYSA-M 0.000 claims abstract description 22
- 239000008151 electrolyte solution Substances 0.000 claims abstract description 21
- 229910001486 lithium perchlorate Inorganic materials 0.000 claims abstract description 21
- 239000002904 solvent Substances 0.000 claims abstract description 17
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 13
- 238000000034 method Methods 0.000 claims abstract description 7
- 239000002341 toxic gas Substances 0.000 claims abstract description 7
- 239000003349 gelling agent Substances 0.000 claims abstract description 5
- 239000011255 nonaqueous electrolyte Substances 0.000 claims abstract description 5
- 229910000510 noble metal Inorganic materials 0.000 claims abstract description 3
- YEJRWHAVMIAJKC-UHFFFAOYSA-N 4-Butyrolactone Chemical compound O=C1CCCO1 YEJRWHAVMIAJKC-UHFFFAOYSA-N 0.000 claims abstract 6
- 239000000243 solution Substances 0.000 claims description 25
- 239000003792 electrolyte Substances 0.000 claims description 22
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 13
- 239000007789 gas Substances 0.000 claims description 13
- 238000001514 detection method Methods 0.000 claims description 7
- 239000003960 organic solvent Substances 0.000 claims description 5
- WGHUNMFFLAMBJD-UHFFFAOYSA-M tetraethylazanium;perchlorate Chemical compound [O-]Cl(=O)(=O)=O.CC[N+](CC)(CC)CC WGHUNMFFLAMBJD-UHFFFAOYSA-M 0.000 claims description 2
- 231100000167 toxic agent Toxicity 0.000 claims description 2
- 239000003440 toxic substance Substances 0.000 claims description 2
- 239000000010 aprotic solvent Substances 0.000 claims 3
- 239000012141 concentrate Substances 0.000 claims 1
- 239000004698 Polyethylene Substances 0.000 abstract 1
- 229940021013 electrolyte solution Drugs 0.000 description 19
- 230000003647 oxidation Effects 0.000 description 12
- 238000007254 oxidation reaction Methods 0.000 description 12
- 239000013043 chemical agent Substances 0.000 description 5
- 238000009835 boiling Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000012528 membrane Substances 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 238000009792 diffusion process Methods 0.000 description 3
- 238000007710 freezing Methods 0.000 description 3
- 230000008014 freezing Effects 0.000 description 3
- -1 hydrogen ions Chemical class 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000005486 organic electrolyte Substances 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000003115 supporting electrolyte Substances 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- UNXNGGMLCSMSLH-UHFFFAOYSA-N dihydrogen phosphate;triethylazanium Chemical compound OP(O)(O)=O.CCN(CC)CC UNXNGGMLCSMSLH-UHFFFAOYSA-N 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000011263 electroactive material Substances 0.000 description 1
- 238000002848 electrochemical method Methods 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000006056 electrooxidation reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000011356 non-aqueous organic solvent Substances 0.000 description 1
- 230000009972 noncorrosive effect Effects 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/403—Cells and electrode assemblies
- G01N27/404—Cells with anode, cathode and cell electrolyte on the same side of a permeable membrane which separates them from the sample fluid, e.g. Clark-type oxygen sensors
- G01N27/4045—Cells with anode, cathode and cell electrolyte on the same side of a permeable membrane which separates them from the sample fluid, e.g. Clark-type oxygen sensors for gases other than oxygen
Abstract
ABSTRACT OF THE DISCLOSURE
Apparatus and method for an electrochemical sensor for detecting a toxic gas, for example, carbon monoxide, in a gelled aprotic organic nonaqueous electrolyte solution are disclosed. The electrolyte solution contains LiClO4, poly-ethylene oxide gelling agent and .gamma.-butyrolactone or propylene carbonate solvent. The electrochemical sensor comprises (a) noble metal electrodes including a sensing electrode, a plat-inum counter electrode and an Ag/Ag+ reference electrode, (b) the electrolyte solution, and (c) adjustable potential elec-trical source means.
Apparatus and method for an electrochemical sensor for detecting a toxic gas, for example, carbon monoxide, in a gelled aprotic organic nonaqueous electrolyte solution are disclosed. The electrolyte solution contains LiClO4, poly-ethylene oxide gelling agent and .gamma.-butyrolactone or propylene carbonate solvent. The electrochemical sensor comprises (a) noble metal electrodes including a sensing electrode, a plat-inum counter electrode and an Ag/Ag+ reference electrode, (b) the electrolyte solution, and (c) adjustable potential elec-trical source means.
Description
'' 12Z0~2Z
The present invention involves the dectection of carbon monoxide (CO) electrochemically using a gelled elect-rolyte containing an amount of polyethylene oxide. An electrolyte solution of approximately l.OM lithium perchlorate (LiC104) in y-butyrolactone or approximately 0.75M LiC104 in propylene carbonate when gelled with polyethylene oxide has been found to be especially suited to the detection of CO by oxidation at the platinum electrode.
Electrochemical reactions based on oxidation or reduction (redox) of metals and compounds at an electrode are highly selective because of the characteristic redox potential at which oxidation or reduction of the electroactive species occures. With electrochemical sensing, selection of the electrode material and electrolyte solution has been very important in determining sensitivity and selectivity.
One limitation of the prior art is that the presence of hydrogen ions, either in the solvent or in the additive (electrolyte), will interfere with the oxidation and reduction of chemical agents sought to be detected. This has lead to the necessity for developing aprotic (free of replaceable hydrogen ions) electrolyte systems.
An aspect of the invention provides an electrochem-ical sensor for toxic gas detection comprising: electro-chemical cell means having therein an electrode configuration comprising a plurality of noble metal electrodes including sensing electrode and a platinum counter electrode and an Ag/Ag reference electrode; a nonaqueous gelled electrolyte solution in said cell means, said solution comprising an aprotic organic solvent based solution wherein said solvent is selected from the group consisting of ~-butyrolactone and lZ20S22 propylene carbonate the solution also containing an amount of lithium perchlorate electrolyte, the gelled solution also containing an amount of polyethylene oxide as the gelling agent; and adjustable potential electrical source means, to energize said electrochemical cell means at desired potentials, connected across said working and counter electrodes.
Another aspect of the invention provides a method for detecting the presence of a plurality of toxic agents comprising the steps of: providing electrochemical cell means having an electrode configuration comprising a plurality of electrodes; providing a nonaqueous gelled electrolyte solution in the electrochemical cell means, said solution comprising an aprotic organic solvent selected from the group consisting of y-butyrolactone and propylene carbonate, the solution also containing an amount of lithium perchlorate electrolyte and polyethylene oxide gelling agent; exposing the electrochem-ical cell means to an atmosphere suspected of containing the gas sought to be detected; and providing electrical source means and connecting the source means to the electrode con-figuration to energize the cell means.
By means of the present invention, an electrochem-ical system has been developed which is extremely sensitive to the presence of CO and can also be used to detect other toxic gases such as nitrogen oxides (N204, NOx) S02, ~2S and the like.
The system includes a nonaqueous, aprotic electro-lyte system of approximately l.OM LiC104 in y-butyrolactone or approximately 0.75M LiC104 in propylene carbonate gelled with a small amount of ~2ZOSZZ
polyethylene oxide (about 1~ by weight based on the other constituents). A platinum electrode is used on the oxidation site for the gas detection. The polymer containing electrolyte solutions have high electrolytic cond~ctivity, low vapor pressure, high solubility for carbon monoxide and high chemical and electrochemical stability. The electrolyte solution and electrodes can be packaged into a low-cost electrochemical cell for detecting carbon monoxide or other gases using a semipermeable membrane coated on one side with platinum metal film as the sensing electrode. The polymer based electrolyte solution can be easily contained in the cell assuring long shelf life.
BRIEF DESCRlPTION OF THE DRAWIN5S
FIGURES 1 and la are schematic diagrams of an electrochemical cell for demonstrating the invention.
FIGURE 2 is a graphical presentation of specific conductance vs. concentraction (25C) of several electrolytes in nonaqueous solvents.
FIGURE 3 is a graphical presentation of potential ranges available in nonaqueous vs. aqueous electrolyte solutions.
FIGURES 4 and 5 show graphical plots of the sensor response to CO.
DESCRIPTION QF T~E PREFERRED EMBODL~E~
FIGURE 1 generally illustrates an electrochemical cell 10 consisting of a chamber 11 having a semipermeable membrane 12 across an opening.
The chamber 11 contains a film of platinum working or sensing electrode 14, a counter electrode 15 of platinum film and a Ag/Ag+ reference electrode 16. An adjustable potential source 20 is connected across the sensing and l~ZOSi22 counter electrode and the current is measured. A
voltage exists but no current flows from the reference electrode to the sensing electrode. A preferred form of this energiZing circuit may include an operational S amplifier as shown in Figure la wherein no current flows in the feedback loop from the reference electrode to the negative input of the operat~onal amplifier. The three electrodes are internally separated by a material which also acts as a wicking material for the electrolyte.
A gelled nonaqueous electrolyte solution 17 permeates and fill~ the chamber. This solution utilizes an aprotic organic solvent such as propylene carbonate or y-butyrolactone and an active electrolyte such as LiC104 which has a wide potential window so that gases sought to be detected can be oxidized or reduced without decomposing the electrolyte solution.
A previously stated, the electrolyte solvent should be aprotic (no replaceable hydrogen atoms) and it should have a high boiling point, low freezing point to provide a wide operating temperature range between boiling point and freezing point, and low vapor pressure so that it is stable. The solvent should have a fairly high dielectric constant and low viscosity so that the solutes are easily soluble, giving solutions with fairly high conductivity. The solvent and electrolyte solutions from such solvents should be electrochemically stable to oxidation and reduction, giving a wide voltage window to carry out electrochemical redox reactions at an electrode surface. The solvent should be low cost, should be easily purified, and should be nontoxic. The following solvents have been chosen for the electrolyte system of the invention.
1~20~2Z
Propylene Pro~erties SlLhQD~g ~=}~I~LI~L~9~e Boiling point (C) 241 202 Freezing point (C) -49 _43 Dielectric constant64.4(25C) 39(20C) Viscosity mP (25C) 25.3 17.5 Density (25C) g/ml 1.19 1.13 The conductivity concentration studies carried out using lithium perchlorate solute as the supporting electrolyte in propylene carbonàte show a maximum conductivity at about 0.75M (Figure 2, curve A) whereas similar studies in the preferred Y-butyrolactone show a much higher maximum conductivity at about lM (Figure 2, curve B).
As seen from the above, solvents such as propylene lS carbonate or Y-butyrolactone have a high boiling point, low melting point, and very low vapor pressure. They are also non-corrosive so that the electrochemical cell can operate over a wide temperature range for an extended period. Gases such as CO are higbly soluble in these nonaqueous organic solvents making for high sensitivity of detection.
With the wide range of potential window avaiIable for oxidation and reduction, many gases can be oxidized or reduced in the same cell so that the electrochemical cell can be used for different gases of interest.
The electrochemical method for the quantitative determination of materials is based on the principle of limiting current density measured at the electrode surface. Limiting current density is defined as the current density resulting from the oxidation or reduction of every molecule of the electroactive 1220~
material or chemical agent reaching the electrode surface. A linear relationship between the limiting current density (iL) and the bulk concentration ~Cb) of the electroactive material or chemical agent can be obtained using Fick's law of diffusion nFD Cb iL =
d where D is the diffusion coefficient of the electroactive molecules in the electrolyte, n is the number of electrons involved, F is the Faraday constant, and~is the diffusion layer thickne~s. Thus, the ~ 3 limiting current density provide~ the quantitative measure of the concentration, while the characteristic lS redox potential identifies the molecules.
FIGURE 3 shows graphically a sample comparison - of potential ranges available in nonaqueous vs. aqueous electrolyte solutions. Aqueous electrolytes are limited to a voltage range of about l.5 volts of redox potential as shown in the figure. The presence of protons in aqueous based electrolytes interferes with redox processes of organic molecules, even within this range.
Aprotic electrolytes (nonaqueous) contain no protons and can achieve three times the voltage range of aqueou~
electrolytes, or about 4.5 volts as shown. Nonaqueous organic electrolytes are preferable for the analysis of C0 and organic compounds such as chemical agents which are more soluble in organic electrolyte solutions compared to aqueous electrolyte solutions.
Electrochemical experiments have been conducted to demonstrate the feasibility of nonaqueous electrochemical redox techniques for the detection and ~22052~
identification of simulants for chemical agents.
Concentrated solutions of supporting electrolytes such as O.5M lithium perchlorate (LiC104) and O.lM
tetraethylammonium perchlorate,(TEAP) in propylene carbonate (PC) or Y-butyrolactone were prepared and used in a conventional electrochemical setup. The sensing and counter electrodes were platinum and the reference electrode was Ag/Ag+. The preferred solvent was Y-butyrolactone. The preferred electrolyte/solvent system is lM LiC104 in Y-butyrolactone. The electrochemical instrumentation con~isted of a Princeton Applied Research Model 173 potentiostat/galvanostat with a Model 175 Universal Programmer, Model 179 digital Coulometer, and Hewlett-Packard Model 7040A x-y recorder.
The gelled nonaqueous electrolyte solution is prepared by dissolving 1~ (by wt.) of the polymer, polyethylene oxide (Molecular weight approximately 100,000) in l.OM LiC104 in Y-butyrolactone or 0.75M
LiC104 in propylene carbonate. The solution in Y-butyrolactone has specific conductivity of 9.89xlO~30hm~lcm~l whereas the solution in propylene carbonate has specific conductivity of 5.389xlO~30hm~1cm~l at 25C. These solutions can be used as media for the dissolution of carbon monoxide gas and the carbon monoxide gas can be oxidized at the platinum electrode surface at a known potential. In the caes of propylene carbonate solution, carbon monoxide can be oxidized at +1.25 to +1.30V VsAg/Ag+ whereas in Y-butyrolactone solution, carbon monoxide can be oxidized at +1.20V VsAg/Ag+. This is illustrated in Figures 4 and 5, respectively. The oxidation shown beyond 1.3V
(curve f of Figure 4) and 1.2V (curve g of lZ20Si2~
Figure 5) are due to oxidation of other components at higher potentials. The very sharp, distinct change in current is very accurate and repeatable. The current generated at these oxidation potential(s) is S proportional to the concentration of carbon monoxide in the electrolyte solution. These electrolyte solutionq are stable to electrochemical oxidation and reduction within the potential range of interest to carbon monoxide detection.
The gelled electrolyte solution~ do not flow through semipermeable membranes like PTFE
(polytetrafluoroethylene) that are used in low cost carbon monoxide sensors and, therefore, the cells can be made to last longer. The polymer containing electrolyte solutions can be packaged easily for sensing C0.
While the invention has been particularly described with reference to C0, other gases such as oxide of nitrogen (N204, N0x) and gases such as S02 and H2S should produce distinct re~ults also. The three electrode configuration cell structure shown in Figure 1 is set up with a small amount of the electrolyte solution ( -lcc) with arrangement to apply a known potential and measuring the current generated. The carbon monoxide gas is allowed to enter the cell through the semipermeable membrane and establish equilibrium state. By applying a potential slightly higher than the oxidation value,lthe electroactive species, namely C0 around the sensing anode is completely oxidized and the current-concentration relation3hip can be established according to the relationship.
The present invention involves the dectection of carbon monoxide (CO) electrochemically using a gelled elect-rolyte containing an amount of polyethylene oxide. An electrolyte solution of approximately l.OM lithium perchlorate (LiC104) in y-butyrolactone or approximately 0.75M LiC104 in propylene carbonate when gelled with polyethylene oxide has been found to be especially suited to the detection of CO by oxidation at the platinum electrode.
Electrochemical reactions based on oxidation or reduction (redox) of metals and compounds at an electrode are highly selective because of the characteristic redox potential at which oxidation or reduction of the electroactive species occures. With electrochemical sensing, selection of the electrode material and electrolyte solution has been very important in determining sensitivity and selectivity.
One limitation of the prior art is that the presence of hydrogen ions, either in the solvent or in the additive (electrolyte), will interfere with the oxidation and reduction of chemical agents sought to be detected. This has lead to the necessity for developing aprotic (free of replaceable hydrogen ions) electrolyte systems.
An aspect of the invention provides an electrochem-ical sensor for toxic gas detection comprising: electro-chemical cell means having therein an electrode configuration comprising a plurality of noble metal electrodes including sensing electrode and a platinum counter electrode and an Ag/Ag reference electrode; a nonaqueous gelled electrolyte solution in said cell means, said solution comprising an aprotic organic solvent based solution wherein said solvent is selected from the group consisting of ~-butyrolactone and lZ20S22 propylene carbonate the solution also containing an amount of lithium perchlorate electrolyte, the gelled solution also containing an amount of polyethylene oxide as the gelling agent; and adjustable potential electrical source means, to energize said electrochemical cell means at desired potentials, connected across said working and counter electrodes.
Another aspect of the invention provides a method for detecting the presence of a plurality of toxic agents comprising the steps of: providing electrochemical cell means having an electrode configuration comprising a plurality of electrodes; providing a nonaqueous gelled electrolyte solution in the electrochemical cell means, said solution comprising an aprotic organic solvent selected from the group consisting of y-butyrolactone and propylene carbonate, the solution also containing an amount of lithium perchlorate electrolyte and polyethylene oxide gelling agent; exposing the electrochem-ical cell means to an atmosphere suspected of containing the gas sought to be detected; and providing electrical source means and connecting the source means to the electrode con-figuration to energize the cell means.
By means of the present invention, an electrochem-ical system has been developed which is extremely sensitive to the presence of CO and can also be used to detect other toxic gases such as nitrogen oxides (N204, NOx) S02, ~2S and the like.
The system includes a nonaqueous, aprotic electro-lyte system of approximately l.OM LiC104 in y-butyrolactone or approximately 0.75M LiC104 in propylene carbonate gelled with a small amount of ~2ZOSZZ
polyethylene oxide (about 1~ by weight based on the other constituents). A platinum electrode is used on the oxidation site for the gas detection. The polymer containing electrolyte solutions have high electrolytic cond~ctivity, low vapor pressure, high solubility for carbon monoxide and high chemical and electrochemical stability. The electrolyte solution and electrodes can be packaged into a low-cost electrochemical cell for detecting carbon monoxide or other gases using a semipermeable membrane coated on one side with platinum metal film as the sensing electrode. The polymer based electrolyte solution can be easily contained in the cell assuring long shelf life.
BRIEF DESCRlPTION OF THE DRAWIN5S
FIGURES 1 and la are schematic diagrams of an electrochemical cell for demonstrating the invention.
FIGURE 2 is a graphical presentation of specific conductance vs. concentraction (25C) of several electrolytes in nonaqueous solvents.
FIGURE 3 is a graphical presentation of potential ranges available in nonaqueous vs. aqueous electrolyte solutions.
FIGURES 4 and 5 show graphical plots of the sensor response to CO.
DESCRIPTION QF T~E PREFERRED EMBODL~E~
FIGURE 1 generally illustrates an electrochemical cell 10 consisting of a chamber 11 having a semipermeable membrane 12 across an opening.
The chamber 11 contains a film of platinum working or sensing electrode 14, a counter electrode 15 of platinum film and a Ag/Ag+ reference electrode 16. An adjustable potential source 20 is connected across the sensing and l~ZOSi22 counter electrode and the current is measured. A
voltage exists but no current flows from the reference electrode to the sensing electrode. A preferred form of this energiZing circuit may include an operational S amplifier as shown in Figure la wherein no current flows in the feedback loop from the reference electrode to the negative input of the operat~onal amplifier. The three electrodes are internally separated by a material which also acts as a wicking material for the electrolyte.
A gelled nonaqueous electrolyte solution 17 permeates and fill~ the chamber. This solution utilizes an aprotic organic solvent such as propylene carbonate or y-butyrolactone and an active electrolyte such as LiC104 which has a wide potential window so that gases sought to be detected can be oxidized or reduced without decomposing the electrolyte solution.
A previously stated, the electrolyte solvent should be aprotic (no replaceable hydrogen atoms) and it should have a high boiling point, low freezing point to provide a wide operating temperature range between boiling point and freezing point, and low vapor pressure so that it is stable. The solvent should have a fairly high dielectric constant and low viscosity so that the solutes are easily soluble, giving solutions with fairly high conductivity. The solvent and electrolyte solutions from such solvents should be electrochemically stable to oxidation and reduction, giving a wide voltage window to carry out electrochemical redox reactions at an electrode surface. The solvent should be low cost, should be easily purified, and should be nontoxic. The following solvents have been chosen for the electrolyte system of the invention.
1~20~2Z
Propylene Pro~erties SlLhQD~g ~=}~I~LI~L~9~e Boiling point (C) 241 202 Freezing point (C) -49 _43 Dielectric constant64.4(25C) 39(20C) Viscosity mP (25C) 25.3 17.5 Density (25C) g/ml 1.19 1.13 The conductivity concentration studies carried out using lithium perchlorate solute as the supporting electrolyte in propylene carbonàte show a maximum conductivity at about 0.75M (Figure 2, curve A) whereas similar studies in the preferred Y-butyrolactone show a much higher maximum conductivity at about lM (Figure 2, curve B).
As seen from the above, solvents such as propylene lS carbonate or Y-butyrolactone have a high boiling point, low melting point, and very low vapor pressure. They are also non-corrosive so that the electrochemical cell can operate over a wide temperature range for an extended period. Gases such as CO are higbly soluble in these nonaqueous organic solvents making for high sensitivity of detection.
With the wide range of potential window avaiIable for oxidation and reduction, many gases can be oxidized or reduced in the same cell so that the electrochemical cell can be used for different gases of interest.
The electrochemical method for the quantitative determination of materials is based on the principle of limiting current density measured at the electrode surface. Limiting current density is defined as the current density resulting from the oxidation or reduction of every molecule of the electroactive 1220~
material or chemical agent reaching the electrode surface. A linear relationship between the limiting current density (iL) and the bulk concentration ~Cb) of the electroactive material or chemical agent can be obtained using Fick's law of diffusion nFD Cb iL =
d where D is the diffusion coefficient of the electroactive molecules in the electrolyte, n is the number of electrons involved, F is the Faraday constant, and~is the diffusion layer thickne~s. Thus, the ~ 3 limiting current density provide~ the quantitative measure of the concentration, while the characteristic lS redox potential identifies the molecules.
FIGURE 3 shows graphically a sample comparison - of potential ranges available in nonaqueous vs. aqueous electrolyte solutions. Aqueous electrolytes are limited to a voltage range of about l.5 volts of redox potential as shown in the figure. The presence of protons in aqueous based electrolytes interferes with redox processes of organic molecules, even within this range.
Aprotic electrolytes (nonaqueous) contain no protons and can achieve three times the voltage range of aqueou~
electrolytes, or about 4.5 volts as shown. Nonaqueous organic electrolytes are preferable for the analysis of C0 and organic compounds such as chemical agents which are more soluble in organic electrolyte solutions compared to aqueous electrolyte solutions.
Electrochemical experiments have been conducted to demonstrate the feasibility of nonaqueous electrochemical redox techniques for the detection and ~22052~
identification of simulants for chemical agents.
Concentrated solutions of supporting electrolytes such as O.5M lithium perchlorate (LiC104) and O.lM
tetraethylammonium perchlorate,(TEAP) in propylene carbonate (PC) or Y-butyrolactone were prepared and used in a conventional electrochemical setup. The sensing and counter electrodes were platinum and the reference electrode was Ag/Ag+. The preferred solvent was Y-butyrolactone. The preferred electrolyte/solvent system is lM LiC104 in Y-butyrolactone. The electrochemical instrumentation con~isted of a Princeton Applied Research Model 173 potentiostat/galvanostat with a Model 175 Universal Programmer, Model 179 digital Coulometer, and Hewlett-Packard Model 7040A x-y recorder.
The gelled nonaqueous electrolyte solution is prepared by dissolving 1~ (by wt.) of the polymer, polyethylene oxide (Molecular weight approximately 100,000) in l.OM LiC104 in Y-butyrolactone or 0.75M
LiC104 in propylene carbonate. The solution in Y-butyrolactone has specific conductivity of 9.89xlO~30hm~lcm~l whereas the solution in propylene carbonate has specific conductivity of 5.389xlO~30hm~1cm~l at 25C. These solutions can be used as media for the dissolution of carbon monoxide gas and the carbon monoxide gas can be oxidized at the platinum electrode surface at a known potential. In the caes of propylene carbonate solution, carbon monoxide can be oxidized at +1.25 to +1.30V VsAg/Ag+ whereas in Y-butyrolactone solution, carbon monoxide can be oxidized at +1.20V VsAg/Ag+. This is illustrated in Figures 4 and 5, respectively. The oxidation shown beyond 1.3V
(curve f of Figure 4) and 1.2V (curve g of lZ20Si2~
Figure 5) are due to oxidation of other components at higher potentials. The very sharp, distinct change in current is very accurate and repeatable. The current generated at these oxidation potential(s) is S proportional to the concentration of carbon monoxide in the electrolyte solution. These electrolyte solutionq are stable to electrochemical oxidation and reduction within the potential range of interest to carbon monoxide detection.
The gelled electrolyte solution~ do not flow through semipermeable membranes like PTFE
(polytetrafluoroethylene) that are used in low cost carbon monoxide sensors and, therefore, the cells can be made to last longer. The polymer containing electrolyte solutions can be packaged easily for sensing C0.
While the invention has been particularly described with reference to C0, other gases such as oxide of nitrogen (N204, N0x) and gases such as S02 and H2S should produce distinct re~ults also. The three electrode configuration cell structure shown in Figure 1 is set up with a small amount of the electrolyte solution ( -lcc) with arrangement to apply a known potential and measuring the current generated. The carbon monoxide gas is allowed to enter the cell through the semipermeable membrane and establish equilibrium state. By applying a potential slightly higher than the oxidation value,lthe electroactive species, namely C0 around the sensing anode is completely oxidized and the current-concentration relation3hip can be established according to the relationship.
Claims (25)
1. An electrochemical sensor for toxic gas detection comprising:
electrochemical cell means having therein an electrode configuration comprising a plurality of noble metal electrodes including sensing electrode and a platinum counter electrode and an Ag/Ag+ reference electrode;
a nonaqueous gelled electrolyte solution in said cell means, said solution comprising an aprotic organic solvent based solution wherein said solvent is selected from the group consisting of .gamma.-butyrolactone and propylene carbonate the solution also containing an amount of lithium perchlorate electrolyte, the gelled solution also containing an amount of polyethylene oxide as the gelling agent;
and adjustable potential electrical source means, to energize said electrochemical cell means at desired potentials, connected across said working and counter electrodes.
electrochemical cell means having therein an electrode configuration comprising a plurality of noble metal electrodes including sensing electrode and a platinum counter electrode and an Ag/Ag+ reference electrode;
a nonaqueous gelled electrolyte solution in said cell means, said solution comprising an aprotic organic solvent based solution wherein said solvent is selected from the group consisting of .gamma.-butyrolactone and propylene carbonate the solution also containing an amount of lithium perchlorate electrolyte, the gelled solution also containing an amount of polyethylene oxide as the gelling agent;
and adjustable potential electrical source means, to energize said electrochemical cell means at desired potentials, connected across said working and counter electrodes.
2. The apparatus according to claim 1 wherein the nonaqueous electrolyte solvent is .gamma.-butyrolactone and said electrolyte is lithium perchlorate (LiClO4) having a concentrate of about 1.0M based on the solvent.
3. The apparatus according to claim 1 wherein the nonaqueous electrolyte solvent is propylene carbonate and said electrolyte is LiClO4 having a concentration of about 0.75M.
4. The apparatus according to claim 2 wherein the amount of said polyethylene oxide is about 1% by weight based on the weight of the solution.
5. The apparatus according to claim 3 wherein the amount of said polyethylene oxide is about 1% by weight based on the weight of the solution.
6. A method for detecting the presence of a plurality of toxic agents comprising the steps of:
providing electrochemical cell means having an electrode configuration comprising a plurality of electrodes;
providing a nonaqueous gelled electrolyte solution in the electrochemical cell means, said solution comprising an aprotic organic solvent selected from the group consisting of .gamma.-butyrolactone and propylene carbonate, the solution also containing an amount of lithium perchlorate electrolyte and polyethylene oxide gelling agent;
exposing the electrochemical cell means to an atmosphere suspected of containing the gas sought to be detected; and providing electrical source means and connecting the source means to the electrode configuration to energize the cell means.
providing electrochemical cell means having an electrode configuration comprising a plurality of electrodes;
providing a nonaqueous gelled electrolyte solution in the electrochemical cell means, said solution comprising an aprotic organic solvent selected from the group consisting of .gamma.-butyrolactone and propylene carbonate, the solution also containing an amount of lithium perchlorate electrolyte and polyethylene oxide gelling agent;
exposing the electrochemical cell means to an atmosphere suspected of containing the gas sought to be detected; and providing electrical source means and connecting the source means to the electrode configuration to energize the cell means.
7. The apparatus according to claim 1, wherein said sensing electrode is a platinum working electrode.
8. The apparatus according to claim 7, which further comprises current measuring means connected across said working and counter electrodes.
9. The apparatus according to claim 8, wherein the aprotic solvent is .gamma.-butyrolactone.
10. The apparatus according to claim 9, wherein the concentration of lithium perchlorate is about 1.0M.
11. The apparatus according to claim 10, wherein the amount of said polyethylene oxide is about 1% by weight based on the weight of the solution.
12. The apparatus according to claim 11, wherein said toxic gas to be detected is carbon monoxide.
13. The apparatus according to claim 8, wherein said working and counter electrodes are in the form of a thin platin-um film.
14. The apparatus according to claim 8, wherein the aprotic solvent is propylene carbonate.
15. The apparatus according to claim 14, wherein the concentration of lithium perchlorate is about 0.75M.
16. The apparatus according to claim 15, wherein the amount of said polyethylene oxide is about 1% by weight based on the weight of the solution.
17. The apparatus according to claim 16, wherein said toxic gas to be detected is carbon monoxide.
18. The apparatus according to claim 8, wherein said electrolyte solution further contains an amount of tetra-ethylammonium perchlorate.
19. The apparatus according to claim 18, wherein the aprotic solvent is .gamma.-butyrolactone.
20. The apparatus according to claim 19, wherein the concentration of lithium perchlorate is about 1.0M.
21. The apparatus according to claim 20, wherein the amount of said polyethylene oxide is about 1% by weight based on the weight of the solution.
22. The apparatus according to claim 21, wherein said toxic gas to be detected is carbon monoxide.
23. The apparatus according to claim 18, wherein said working and counter electrodes are in the form of a thin platinum film.
24. The method according to claim 6, wherein said plural-ity of electrodes comprise a platinum working electrode, a platinum counter electrode and an Ag/Ag+ reference electrode.
25. The method according to claim 24, which further com-prises providing means for measuring the current flowing between said sensing electrode and said counter electrode.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/557,072 US4522690A (en) | 1983-12-01 | 1983-12-01 | Electrochemical sensing of carbon monoxide |
| US557,072 | 1983-12-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1220522A true CA1220522A (en) | 1987-04-14 |
Family
ID=24223948
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000469013A Expired CA1220522A (en) | 1983-12-01 | 1984-11-30 | Electrochemical sensing of carbon monoxide |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US4522690A (en) |
| EP (1) | EP0163728B1 (en) |
| JP (1) | JPS61500566A (en) |
| CA (1) | CA1220522A (en) |
| DE (1) | DE3478954D1 (en) |
| DK (1) | DK350085D0 (en) |
| NO (1) | NO852873L (en) |
| WO (1) | WO1985002465A1 (en) |
Families Citing this family (111)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4591414A (en) * | 1984-08-27 | 1986-05-27 | The United States Of America As Represented By The United States Department Of Energy | Method of determining methane and electrochemical sensor therefor |
| EP0218694A1 (en) * | 1985-04-19 | 1987-04-22 | The Regents Of The University Of California | Transparent multi-oxygen sensor array |
| US4781798A (en) * | 1985-04-19 | 1988-11-01 | The Regents Of The University Of California | Transparent multi-oxygen sensor array and method of using same |
| US4662996A (en) * | 1985-12-20 | 1987-05-05 | Honeywell Inc. | Method and electrochemical sensor for sensing chemical agents using a sensing elctrode coated with electrically conductive polymers |
| DE3609402A1 (en) * | 1986-03-20 | 1987-09-24 | Bayer Diagnostic & Electronic | METHOD FOR PRODUCING ELECTROCHEMICAL GAS SENSORS |
| US4744954A (en) * | 1986-07-11 | 1988-05-17 | Allied-Signal Inc. | Amperometric gas sensor containing a solid electrolyte |
| US4851088A (en) * | 1987-03-05 | 1989-07-25 | Honeywell Inc. | Electrochemical detection of carbon dioxide |
| US4948490A (en) * | 1988-02-19 | 1990-08-14 | Honeywell Inc. | Tetraalkylammonium ion solid electrolytes |
| US5173166A (en) * | 1990-04-16 | 1992-12-22 | Minitech Co. | Electrochemical gas sensor cells |
| US5302274A (en) * | 1990-04-16 | 1994-04-12 | Minitech Co. | Electrochemical gas sensor cells using three dimensional sensing electrodes |
| CA2050057A1 (en) | 1991-03-04 | 1992-09-05 | Adam Heller | Interferant eliminating biosensors |
| US5593852A (en) | 1993-12-02 | 1997-01-14 | Heller; Adam | Subcutaneous glucose electrode |
| US5338429A (en) * | 1993-03-05 | 1994-08-16 | Mine Safety Appliances Company | Electrochemical toxic gas sensor |
| GB2303710A (en) * | 1993-03-05 | 1997-02-26 | Mine Safety Appliances Co | Electrochemical toxic gas sensor with gas permeable membrane |
| US5497772A (en) * | 1993-11-19 | 1996-03-12 | Alfred E. Mann Foundation For Scientific Research | Glucose monitoring system |
| US5791344A (en) * | 1993-11-19 | 1998-08-11 | Alfred E. Mann Foundation For Scientific Research | Patient monitoring system |
| WO1995014226A1 (en) * | 1993-11-19 | 1995-05-26 | Ceramatec, Inc. | Multi-functional sensor for combustion systems |
| DE19515392C2 (en) * | 1995-04-26 | 1997-07-17 | Prominent Dosiertechnik Gmbh | Electrochemical measuring cell |
| US6051123A (en) * | 1995-06-15 | 2000-04-18 | Gas Research Institute | Multi-functional and NOx sensor for combustion systems |
| US5591896A (en) * | 1995-11-02 | 1997-01-07 | Lin; Gang | Solid-state gas sensors |
| US5746900A (en) * | 1996-03-07 | 1998-05-05 | H.V. Setty Enterprises, Inc. | Non-aqueous amperometric multi-gas sensor |
| GB2323673B (en) * | 1996-03-15 | 2000-01-12 | Mine Safety Appliances Co | Electrochemical sensor with a non-aqueous electrolyte system |
| US6488826B2 (en) * | 1996-12-09 | 2002-12-03 | Patrick Altmeier | Fluid electrode system for resistive slope sensors |
| JP3394262B2 (en) * | 1997-02-06 | 2003-04-07 | セラセンス、インク． | Small volume in vitro analyte sensor |
| US6001240A (en) * | 1997-07-02 | 1999-12-14 | Mine Safety Appliances Company | Electrochemical detection of hydrogen cyanide |
| US6098523A (en) * | 1997-07-10 | 2000-08-08 | Draeger Safety, Inc. | Testing apparatus for gas sensors |
| CA2215108C (en) * | 1997-09-11 | 1999-10-26 | Senco Sensors Inc. | Electrochemical gas sensor |
| CA2245050C (en) * | 1997-09-11 | 2000-09-05 | Kehoe Component Sales Inc. Dba Pace Electronic Products Inc. | Three-electrode electrochemical gas sensor |
| US6103033A (en) | 1998-03-04 | 2000-08-15 | Therasense, Inc. | Process for producing an electrochemical biosensor |
| US6134461A (en) * | 1998-03-04 | 2000-10-17 | E. Heller & Company | Electrochemical analyte |
| US8480580B2 (en) | 1998-04-30 | 2013-07-09 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
| US8974386B2 (en) | 1998-04-30 | 2015-03-10 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
| US8688188B2 (en) | 1998-04-30 | 2014-04-01 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
| US8465425B2 (en) | 1998-04-30 | 2013-06-18 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
| US6175752B1 (en) | 1998-04-30 | 2001-01-16 | Therasense, Inc. | Analyte monitoring device and methods of use |
| US8346337B2 (en) | 1998-04-30 | 2013-01-01 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
| US9066695B2 (en) | 1998-04-30 | 2015-06-30 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
| US6949816B2 (en) | 2003-04-21 | 2005-09-27 | Motorola, Inc. | Semiconductor component having first surface area for electrically coupling to a semiconductor chip and second surface area for electrically coupling to a substrate, and method of manufacturing same |
| US6251260B1 (en) | 1998-08-24 | 2001-06-26 | Therasense, Inc. | Potentiometric sensors for analytic determination |
| US6591125B1 (en) | 2000-06-27 | 2003-07-08 | Therasense, Inc. | Small volume in vitro analyte sensor with diffusible or non-leachable redox mediator |
| US6338790B1 (en) | 1998-10-08 | 2002-01-15 | Therasense, Inc. | Small volume in vitro analyte sensor with diffusible or non-leachable redox mediator |
| EP2322645A1 (en) | 1999-06-18 | 2011-05-18 | Abbott Diabetes Care Inc. | Mass transport limited in vivo analyte sensor |
| US6616819B1 (en) | 1999-11-04 | 2003-09-09 | Therasense, Inc. | Small volume in vitro analyte sensor and methods |
| US6560471B1 (en) | 2001-01-02 | 2003-05-06 | Therasense, Inc. | Analyte monitoring device and methods of use |
| JP3718467B2 (en) * | 2001-03-28 | 2005-11-24 | 株式会社東芝 | Non-aqueous electrolyte and non-aqueous electrolyte secondary battery |
| WO2002078512A2 (en) | 2001-04-02 | 2002-10-10 | Therasense, Inc. | Blood glucose tracking apparatus and methods |
| US7381184B2 (en) | 2002-11-05 | 2008-06-03 | Abbott Diabetes Care Inc. | Sensor inserter assembly |
| EP2305813A3 (en) * | 2002-11-14 | 2012-03-28 | Dharmacon, Inc. | Fuctional and hyperfunctional sirna |
| US7811231B2 (en) | 2002-12-31 | 2010-10-12 | Abbott Diabetes Care Inc. | Continuous glucose monitoring system and methods of use |
| US8066639B2 (en) | 2003-06-10 | 2011-11-29 | Abbott Diabetes Care Inc. | Glucose measuring device for use in personal area network |
| USD914881S1 (en) | 2003-11-05 | 2021-03-30 | Abbott Diabetes Care Inc. | Analyte sensor electronic mount |
| WO2005089103A2 (en) | 2004-02-17 | 2005-09-29 | Therasense, Inc. | Method and system for providing data communication in continuous glucose monitoring and management system |
| US9788771B2 (en) | 2006-10-23 | 2017-10-17 | Abbott Diabetes Care Inc. | Variable speed sensor insertion devices and methods of use |
| US8512243B2 (en) | 2005-09-30 | 2013-08-20 | Abbott Diabetes Care Inc. | Integrated introducer and transmitter assembly and methods of use |
| US9572534B2 (en) | 2010-06-29 | 2017-02-21 | Abbott Diabetes Care Inc. | Devices, systems and methods for on-skin or on-body mounting of medical devices |
| US9743862B2 (en) | 2011-03-31 | 2017-08-29 | Abbott Diabetes Care Inc. | Systems and methods for transcutaneously implanting medical devices |
| US8333714B2 (en) | 2006-09-10 | 2012-12-18 | Abbott Diabetes Care Inc. | Method and system for providing an integrated analyte sensor insertion device and data processing unit |
| US7883464B2 (en) | 2005-09-30 | 2011-02-08 | Abbott Diabetes Care Inc. | Integrated transmitter unit and sensor introducer mechanism and methods of use |
| US8613703B2 (en) | 2007-05-31 | 2013-12-24 | Abbott Diabetes Care Inc. | Insertion devices and methods |
| US20090105569A1 (en) | 2006-04-28 | 2009-04-23 | Abbott Diabetes Care, Inc. | Introducer Assembly and Methods of Use |
| US7697967B2 (en) | 2005-12-28 | 2010-04-13 | Abbott Diabetes Care Inc. | Method and apparatus for providing analyte sensor insertion |
| US9351669B2 (en) | 2009-09-30 | 2016-05-31 | Abbott Diabetes Care Inc. | Interconnect for on-body analyte monitoring device |
| US10226207B2 (en) | 2004-12-29 | 2019-03-12 | Abbott Diabetes Care Inc. | Sensor inserter having introducer |
| US7731657B2 (en) | 2005-08-30 | 2010-06-08 | Abbott Diabetes Care Inc. | Analyte sensor introducer and methods of use |
| US8571624B2 (en) | 2004-12-29 | 2013-10-29 | Abbott Diabetes Care Inc. | Method and apparatus for mounting a data transmission device in a communication system |
| US9398882B2 (en) | 2005-09-30 | 2016-07-26 | Abbott Diabetes Care Inc. | Method and apparatus for providing analyte sensor and data processing device |
| US9259175B2 (en) | 2006-10-23 | 2016-02-16 | Abbott Diabetes Care, Inc. | Flexible patch for fluid delivery and monitoring body analytes |
| US8112240B2 (en) | 2005-04-29 | 2012-02-07 | Abbott Diabetes Care Inc. | Method and apparatus for providing leak detection in data monitoring and management systems |
| US20060278536A1 (en) * | 2005-06-10 | 2006-12-14 | The Regents Of The University Of California | Sensor comprising supported aprotic ionic liquid |
| WO2007020410A1 (en) * | 2005-08-12 | 2007-02-22 | Isis Innovation Limited | Detection of ammonia by electrodes comprising glassy carbon or boron-doped diamond |
| US9521968B2 (en) | 2005-09-30 | 2016-12-20 | Abbott Diabetes Care Inc. | Analyte sensor retention mechanism and methods of use |
| US7766829B2 (en) | 2005-11-04 | 2010-08-03 | Abbott Diabetes Care Inc. | Method and system for providing basal profile modification in analyte monitoring and management systems |
| EP1968432A4 (en) | 2005-12-28 | 2009-10-21 | Abbott Diabetes Care Inc | Medical device insertion |
| US11298058B2 (en) | 2005-12-28 | 2022-04-12 | Abbott Diabetes Care Inc. | Method and apparatus for providing analyte sensor insertion |
| US7885698B2 (en) | 2006-02-28 | 2011-02-08 | Abbott Diabetes Care Inc. | Method and system for providing continuous calibration of implantable analyte sensors |
| DE102006014714B3 (en) * | 2006-03-30 | 2007-05-16 | Draegerwerk Ag | Electrochemical sensor for gas detection has aromatic or alphatic acid carbonic acids in alkali electrolyte solution |
| DE102006014715B3 (en) * | 2006-03-30 | 2007-06-06 | Drägerwerk AG | Electrochemical gas sensor for detecting analyte, has mediator that is dissolved in saturated form in electrolytes and is available as precipitate in electrolyte space, and protection electrode arranged at rear of measuring electrode |
| US7620438B2 (en) | 2006-03-31 | 2009-11-17 | Abbott Diabetes Care Inc. | Method and system for powering an electronic device |
| US8226891B2 (en) | 2006-03-31 | 2012-07-24 | Abbott Diabetes Care Inc. | Analyte monitoring devices and methods therefor |
| US20080071158A1 (en) | 2006-06-07 | 2008-03-20 | Abbott Diabetes Care, Inc. | Analyte monitoring system and method |
| US8732188B2 (en) | 2007-02-18 | 2014-05-20 | Abbott Diabetes Care Inc. | Method and system for providing contextual based medication dosage determination |
| US8930203B2 (en) | 2007-02-18 | 2015-01-06 | Abbott Diabetes Care Inc. | Multi-function analyte test device and methods therefor |
| US8123686B2 (en) | 2007-03-01 | 2012-02-28 | Abbott Diabetes Care Inc. | Method and apparatus for providing rolling data in communication systems |
| US8665091B2 (en) | 2007-05-08 | 2014-03-04 | Abbott Diabetes Care Inc. | Method and device for determining elapsed sensor life |
| US7928850B2 (en) | 2007-05-08 | 2011-04-19 | Abbott Diabetes Care Inc. | Analyte monitoring system and methods |
| US8461985B2 (en) | 2007-05-08 | 2013-06-11 | Abbott Diabetes Care Inc. | Analyte monitoring system and methods |
| US8456301B2 (en) | 2007-05-08 | 2013-06-04 | Abbott Diabetes Care Inc. | Analyte monitoring system and methods |
| US8103456B2 (en) | 2009-01-29 | 2012-01-24 | Abbott Diabetes Care Inc. | Method and device for early signal attenuation detection using blood glucose measurements |
| US9402544B2 (en) | 2009-02-03 | 2016-08-02 | Abbott Diabetes Care Inc. | Analyte sensor and apparatus for insertion of the sensor |
| US20100213057A1 (en) | 2009-02-26 | 2010-08-26 | Benjamin Feldman | Self-Powered Analyte Sensor |
| WO2010127050A1 (en) | 2009-04-28 | 2010-11-04 | Abbott Diabetes Care Inc. | Error detection in critical repeating data in a wireless sensor system |
| WO2010138856A1 (en) | 2009-05-29 | 2010-12-02 | Abbott Diabetes Care Inc. | Medical device antenna systems having external antenna configurations |
| US9314195B2 (en) | 2009-08-31 | 2016-04-19 | Abbott Diabetes Care Inc. | Analyte signal processing device and methods |
| EP2473099A4 (en) | 2009-08-31 | 2015-01-14 | Abbott Diabetes Care Inc | Analyte monitoring system and methods for managing power and noise |
| WO2011041469A1 (en) | 2009-09-29 | 2011-04-07 | Abbott Diabetes Care Inc. | Method and apparatus for providing notification function in analyte monitoring systems |
| USD924406S1 (en) | 2010-02-01 | 2021-07-06 | Abbott Diabetes Care Inc. | Analyte sensor inserter |
| JP5904500B2 (en) | 2010-03-24 | 2016-04-13 | アボット ダイアベティス ケア インコーポレイテッドＡｂｂｏｔｔ Ｄｉａｂｅｔｅｓ Ｃａｒｅ Ｉｎｃ． | Apparatus and system for inserting sharp member under skin surface |
| US11064921B2 (en) | 2010-06-29 | 2021-07-20 | Abbott Diabetes Care Inc. | Devices, systems and methods for on-skin or on-body mounting of medical devices |
| US20120193229A1 (en) * | 2011-01-27 | 2012-08-02 | Life Safety Distribution Ag | Electrochemical Oxygen Sensor with Internal Barrier to Oxygen Diffusion |
| WO2013070794A2 (en) | 2011-11-07 | 2013-05-16 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods |
| US9402570B2 (en) | 2011-12-11 | 2016-08-02 | Abbott Diabetes Care Inc. | Analyte sensor devices, connections, and methods |
| US9459233B2 (en) | 2012-06-25 | 2016-10-04 | Steris Corporation | Amperometric gas sensor |
| US9968306B2 (en) | 2012-09-17 | 2018-05-15 | Abbott Diabetes Care Inc. | Methods and apparatuses for providing adverse condition notification with enhanced wireless communication range in analyte monitoring systems |
| GB2516932B (en) | 2013-08-07 | 2018-12-26 | Nokia Technologies Oy | An apparatus and associated methods for water detection |
| US9983164B1 (en) * | 2015-03-18 | 2018-05-29 | Maxim Integrated Products, Inc. | Mobile electrochemical air quality meter |
| US10213139B2 (en) | 2015-05-14 | 2019-02-26 | Abbott Diabetes Care Inc. | Systems, devices, and methods for assembling an applicator and sensor control device |
| US10674944B2 (en) | 2015-05-14 | 2020-06-09 | Abbott Diabetes Care Inc. | Compact medical device inserters and related systems and methods |
| US11071478B2 (en) | 2017-01-23 | 2021-07-27 | Abbott Diabetes Care Inc. | Systems, devices and methods for analyte sensor insertion |
| US10876144B2 (en) | 2017-07-14 | 2020-12-29 | American Sterilizer Company | Process for determining viability of test microorganisms of biological indicator and sterilization detection device for determining same |
| US10889848B2 (en) | 2017-07-14 | 2021-01-12 | American Sterilizer Company | Process for determining viability of test microorganisms of biological indicator and sterilization detection device for determining same |
| US10900062B2 (en) | 2017-07-14 | 2021-01-26 | American Sterilizer Company | Process for determining viability of test microorganisms of biological indicator and sterilization detection device for determining same |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3260656A (en) * | 1962-09-27 | 1966-07-12 | Corning Glass Works | Method and apparatus for electrolytically determining a species in a fluid |
| US3833495A (en) * | 1970-09-28 | 1974-09-03 | Gen Electric | Reference electrode half cell |
| JPS4720939U (en) * | 1971-04-05 | 1972-11-09 | ||
| JPS4829631U (en) * | 1971-08-13 | 1973-04-11 | ||
| DE2436261B2 (en) * | 1974-07-27 | 1976-11-25 | Bayer Ag, 5090 Leverkusen | ELECTROCHEMICAL GAS DETECTORS |
| JPS52116652A (en) * | 1976-03-26 | 1977-09-30 | Japan Electronic Control Syst | Dish washer |
| DE2621676C3 (en) * | 1976-05-15 | 1979-01-11 | Bayer Ag, 5090 Leverkusen | Electrochemical gas detector for the detection of gas traces |
| DE2657570C3 (en) * | 1976-12-18 | 1980-11-20 | Bayer Ag, 5090 Leverkusen | Electrochemical cell for the detection of hydrogen sulfide in a gas mixture |
| US4197176A (en) * | 1976-12-27 | 1980-04-08 | Minas Ensanian | Apparatus for measuring surface characteristics of metals and metalloids |
| US4169779A (en) * | 1978-12-26 | 1979-10-02 | Catalyst Research Corporation | Electrochemical cell for the detection of hydrogen sulfide |
| DE3033796A1 (en) * | 1980-09-09 | 1982-04-22 | Bayer Ag, 5090 Leverkusen | ELECTROCHEMICAL SENSOR FOR DETECTING REDUCING GASES, ESPECIALLY CARBON MONOXIDE, HYDRAZINE AND HYDROGEN IN AIR |
-
1983
- 1983-12-01 US US06/557,072 patent/US4522690A/en not_active Expired - Lifetime
-
1984
- 1984-11-28 WO PCT/US1984/001954 patent/WO1985002465A1/en not_active Application Discontinuation
- 1984-11-28 EP EP85900346A patent/EP0163728B1/en not_active Expired
- 1984-11-28 DE DE8585900346T patent/DE3478954D1/en not_active Expired
- 1984-11-28 JP JP60500129A patent/JPS61500566A/en active Pending
- 1984-11-30 CA CA000469013A patent/CA1220522A/en not_active Expired
-
1985
- 1985-07-18 NO NO852873A patent/NO852873L/en unknown
- 1985-08-01 DK DK350085A patent/DK350085D0/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61500566A (en) | 1986-03-27 |
| EP0163728A1 (en) | 1985-12-11 |
| US4522690A (en) | 1985-06-11 |
| DK350085A (en) | 1985-08-01 |
| DK350085D0 (en) | 1985-08-01 |
| WO1985002465A1 (en) | 1985-06-06 |
| DE3478954D1 (en) | 1989-08-17 |
| EP0163728A4 (en) | 1986-06-05 |
| NO852873L (en) | 1985-07-18 |
| EP0163728B1 (en) | 1989-07-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1220522A (en) | Electrochemical sensing of carbon monoxide | |
| Osborne et al. | Micro-hole interface for the amperometric determination of ionic species in aqueous solutions | |
| US4474648A (en) | Gas sensor | |
| US4568445A (en) | Electrode system for an electro-chemical sensor for measuring vapor concentrations | |
| US4662996A (en) | Method and electrochemical sensor for sensing chemical agents using a sensing elctrode coated with electrically conductive polymers | |
| KR100358933B1 (en) | Planar reference electrode | |
| GB1080343A (en) | Electrochemical device | |
| EP0154982A2 (en) | Electrochemical sensor | |
| Wang | [38] Amperometric hydrogen electrode | |
| Müller | Polarographic Study with a Microelectrode Past which an Electrolyte is Flowing1 | |
| US4591414A (en) | Method of determining methane and electrochemical sensor therefor | |
| US3915831A (en) | Hydrogen sulfide sensing cell | |
| LaConti et al. | Electrochemical detection of H2, CO, and hydrocarbons in inert or oxygen atmospheres | |
| WO1999001757A1 (en) | Electrochemical sensor for the detection of hydrogen cyanide and method of use thereof | |
| Stetter et al. | The electrochemical oxidation of hydrazine and methylhydrazine on gold: application to gas monitoring | |
| US3897315A (en) | Method of determining hydrogen sulfide | |
| JPH08500444A (en) | Chlorine sensor | |
| US4595486A (en) | Electrochemical gas sensor | |
| EP0704054B1 (en) | Determining gas concentration | |
| US5746900A (en) | Non-aqueous amperometric multi-gas sensor | |
| Lee | Electrochemical phenomena at a rotating mercury electrode. I. Reduction of metal ions | |
| Stevens et al. | Coated-wire cadmium ion-selective electrode based on the bidentate neutral carrier 4, 4′-di (5-nonyl)-2, 2′-bipyridine | |
| US5403452A (en) | Method for determining gas concentrations and gas sensor with a solid electrolyte | |
| Lyu et al. | Coulometric ion sensing with Li+-selective LiMn2O4 electrodes | |
| US4235689A (en) | Apparatus for detecting traces of a gas |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |