Differential probe with low-slope component

Patent metadata

Field	Value
Publication number	US-11959870-B2
Application number	US-202217569076-A
Country	US
Kind code	B2
Filing date	Jan 5, 2022
Priority date	Jan 5, 2022
Publication date	Apr 16, 2024
Grant date	Apr 16, 2024

Abstract

An embodiment provides a method for measuring an analyte of a sample, including: introducing a sample to a sample region of a measurement device; the measurement device comprising: a measurement electrode and a ground electrode contacting the sample; a low-slope reference electrode in a reference electrode assembly having an electrolyte solution, wherein the electrolyte solution is in contact with the low-slope reference electrode; wherein the electrolyte solution is electrically coupled to the sample via at least one junction; and measuring a first potential between the measurement electrode and the ground electrode; measuring a second potential between the low-slope reference electrode and the ground electrode; determining an analyte in the sample by comparing the first potential and the second potential. Other aspects are described and claimed.

First claim

What is claimed is:

1. A method for measuring an analyte of a sample, comprising:
introducing a sample to a sample region of a measurement device;
the measurement device comprising:
a measurement electrode and a ground electrode contacting the sample;
a low-slope reference electrode, in a reference electrode assembly, having a sensitivity to an analyte of less than about 55 mV/decade, wherein the electrolyte solution has a first composition after the sample has been introduced, wherein the electrolyte solution is in contact with the low-slope reference electrode, wherein the electrolyte solution is electrically coupled to the sample via at least one junction wherein the low-slope reference electrode comprises an ion selective electrode for a particular ion in a solution comprising the particular ion; and

measuring a first potential between the measurement electrode and the ground electrode;
measuring a second potential between the low-slope reference electrode and the ground electrode;
determining the analyte in the sample by comparing the first potential and the second potential, wherein the comparing represents a hydrogen ion activity in the sample.

2. The method of claim 1 , wherein the analyte comprises a plurality of hydrogen ions.

3. The method of claim 2 , wherein the plurality of hydrogen ions correlates to a pH of the sample.

4. The method of claim 1 , wherein the low-slope reference electrode has an absolute sensitivity of less than 55 mV/pH unit.

5. The method of claim 1 , wherein the low-slope reference electrode comprises a calcium ion selective electrode in a solution with calcium ions.

6. The method of claim 1 , wherein the low-slope reference electrode comprises a magnesium ion selective electrode in a solution with magnesium ions.

7. The method of claim 1 , wherein the low-slope reference electrode comprises a sulfate ion selective electrode in a solution with sulfate ions.

8. The method of claim 1 , wherein the low-slope reference electrode comprises a phosphate ion selective electrode in a solution with phosphate ions.

9. The method of claim 1 , wherein the low-slope reference electrode comprises a barium ion selective electrode in a solution with barium ions.

10. The method of claim 1 , wherein a change in the first composition of the electrolyte solution surrounding the low-slope reference electrode causes a drift in the potential that reduces a magnitude of the change the second measured potential compared to a method using a reference electrode having a higher slope.

11. A device for measuring an analyte of a sample, comprising:
a measurement electrode and a ground electrode contacting the sample;
a low-slope reference electrode, in a reference electrode assembly, having a sensitivity to an analyte of less than about 55 mV/decade, wherein the electrolyte solution is in contact with the low-slope reference electrode, wherein the electrolyte solution is electrically coupled to the sample via at least one junction, wherein the low-slope reference electrode comprises an ion selective electrode for a particular ion in a solution comprising the particular ion;
a processor;
a memory device that stores instructions executable by the processor to:
measure a first potential between the measurement electrode and the ground electrode;
measure a second potential between the low-slope reference electrode and the ground electrode;
determine the analyte in the sample by comparing the first potential and the second potential, wherein the comparing represents a hydrogen ion activity in the sample.

12. The device of claim 11 , wherein the analyte comprises a plurality of hydrogen ions.

13. The device of claim 12 , wherein the plurality of hydrogen ions correlates to a pH of the sample.

14. The device of claim 11 , wherein the low-slope reference electrode has an absolute sensitivity of less than 55 mV/pH unit.

15. The device of claim 11 , wherein the low-slope reference electrode comprises a calcium ion selective electrode in a solution with calcium ions.

16. The device of claim 11 , wherein the low-slope reference electrode comprises a magnesium ion selective electrode in a solution with magnesium ions.

17. The device of claim 11 , wherein the low-slope reference electrode comprises a sulfate ion selective electrode in a solution with sulfate ions.

18. The device of claim 11 , wherein the low-slope reference electrode comprises a phosphate ion selective electrode in a solution with phosphate ions.

19. The device of claim 11 , wherein the low-slope reference electrode comprises a barium ion selective electrode in a solution with barium ions.

20. A method for measuring the pH of a sample, comprising:
introducing a sample to a sample region of a measurement device;
the measurement device comprising:
a pH measurement electrode and a ground electrode contacting the sample;
a low-slope reference electrode, in a reference electrode assembly, having a sensitivity to an analyte of less than about 55 mV/decade, wherein the electrolyte solution is in contact with the low-slope reference electrode, wherein the electrolyte solution is electrically coupled to the sample via at least one salt bridge, wherein the low-slope reference electrode comprises an ion selective electrode for a particular ion in a solution comprising the particular ion;

measuring a first potential between the pH measurement electrode and the ground electrode;
measuring a second potential between the low-slope reference electrode and the ground electrode; and
determining a pH based on hydrogen ion concentration in the sample by comparing the first potential and the second potential.

Assignees

• Hach Co

Inventors

• Salzer Corey Alan
• Young Russell

Classifications

• G01N27/302 Primary

  pH sensitive, e.g. quinhydron, antimony or hydrogen electrodes (ion selective electrodes G01N27/333, glass electrodes G01N27/36) · CPC title

• G01N27/301

  Reference electrodes · CPC title

• G01N27/333

  Ion-selective electrodes or membranes (glass electrodes G01N27/36) · CPC title

• G01N27/4035

  Combination of a single ion-sensing electrode and a single reference electrode (G01N27/406 and G01N27/413 take precedence) · CPC title

• G01N27/4167 Primary

  pH (electrodes therefor G01N27/302, G01N27/36) · CPC title