Electrochemical probe

Patent metadata

Field	Value
Publication number	US-2024426773-A1
Application number	US-202218692157-A
Country	US
Kind code	A1
Filing date	Sep 15, 2022
Priority date	Sep 17, 2021
Publication date	Dec 26, 2024
Grant date	—

Abstract

Novel type of electrochemical probe comprising a reference electrode array, each reference electrode comprising a conductor element. The set-up allows for internal calibration as well as being adapted to long storage in dry state. Individual conductive elements of the electrode array do not start to shift/drift, simultaneously but that it is rather individual conductive elements that show deviating behavior. Relatively simple statistical analysis of the respective voltages obtained for the respective conductive elements of the reference electrode array allow identifying such deviating conductive elements, and then take corrective action, such as for example disregarding the measured values provided by such deviating conductive element or regenerating such deviating conductive elements by applying a voltage to re-chlorinate or electrochemical snibbing the surface of such element for cleaning purposes, which can also be done with the respective probe or reference electrode remaining in place, i.e. without for example having to remove the junction element comprising the electrolyte.

First claim

1 . Probe for potentiometric measurements, the probe comprising
(i) an electrode array comprising at least two conductive elements electrically isolated against each other, exposing a conductive surface; (ii) a junction element comprising an absorbent material and an electrolyte, connecting the conductive surface of said conductive elements to a liquid; (iii) a measuring device capable of measuring voltages between the conductive elements comprised in the electrode array; and (iv) connecting means for connecting the electrode array and the measuring device.

2 . Probe according to claim 1 , wherein the electrode array comprises at least three and at most twelve conductive elements.

3 . Probe according to claim 1 , wherein the conductive elements comprise a conductive material selected from the group consisting of silver, gold, platinum, mercury, carbon, and any blend thereof, and preferably the conductive material is silver.

4 . Probe according to claim 1 , wherein the conductive elements are pellet-shaped.

5 . Probe according to claim 1 , wherein the absorbent material is either a porous material.

6 . Probe according to claim 1 , wherein the electrolyte is an alkaline metal chloride.

7 . Probe according to claim 1 , wherein the measuring device is an electronic circuitry which is connected to and measuring voltage between the conductive elements.

8 . Probe according to claim 7 , wherein the electronic circuitry is able to selectively address any one or more individual conductive elements, and/or to selectively apply a current to any one or more individual conductive element.

9 . Probe according to claim 1 , wherein the probe further comprises a controller unit that (i) controls the electronic circuitry, (ii) is capable of connecting and/or addressing the conductive elements either singly or in any combination, and (iii) is capable of identifying and handling unstable conductive elements in the electrode array.

10 . Probe according to claim 9 , wherein the controller handles unstable conductive elements in the electrode array by selectively applying current with selected polarity to such at least one deviating conductive element for electrochemical scrubbing and coating.

11 . Probe according to c claim 1 , wherein the electrode array is immersed in an aqueous solution of the electrolyte.

12 . Probe according to claim 1 , further comprising an electrochemical sensor, the electrochemical sensor preferably being an ion-sensitive field-effect transistor (ISFET).

13 . Vessel or conduit comprising the probe of claim 1 .

14 . System comprising the vessel of claim 13 , said system being selected from the group consisting of water purification system, and water solution preparation system.

15 . Method of determining an ion concentration in solution, the method comprising in sequential order the steps of
(a) providing an electrode array comprising at least two conductive elements electrically isolated against each other, exposing a conductive surface; a junction element comprising an absorbent material and an electrolyte; a measuring device capable of measuring voltages between the conductive elements comprised in the electrode array; and connecting means for connecting the electrode array and the measuring device; (b) (b′) submersing the electrode array and the junction element in a liquid and connecting it to the measuring device; or
(b″) submersing the electrode array connected to the measuring device in a liquid;
(c) obtaining a voltage value for each of the conductive elements comprised in the electrode array by using the measuring device; and (d) performing statistical analysis of the voltage values obtained in step (c) to identify any deviating conductive element, and to calculate an average reference voltage, wherein steps (a), (b), (c), and (d) are performed in sequential order.

16 . Method of determining an ion concentration in solution, the method comprising in sequential order the steps of
(a) providing an electrode array comprising at least two conductive elements electrically isolated against each other, exposing a conductive surface; a junction element comprising an absorbent material and an electrolyte; a measuring device capable of measuring voltages between the conductive elements comprised in the electrode array; and connecting means for connecting the electrode array and the measuring device; (b) (b′) submersing the electrode array and the junction element in a liquid and connecting it to the measuring device; or
(b″) submersing the electrode array connected to the measuring device in a liquid;
(c) obtaining a voltage value for each of the conductive elements comprised in the electrode array by using the measuring device; and (d) performing statistical analysis of the voltage values obtained in step (c) to identify any deviating conductive element, and to calculate an average reference voltage, wherein steps (a), (b), (c), and (d) are performed in sequential order; said method further comprising (e) providing an electrochemical sensor as defined in claim 12 in an aqueous ion solution; (f) subsequently taking a voltage measurement from the electrochemical sensor; and (g) use a calculation device to determine the ion concentration on basis of the average reference voltage obtained in step (d) and the voltage measurement of step (f), wherein steps (a) to (f) may be performed in any order provided that (i) steps (a) to (d) are performed sequentially; (ii) steps (f) and (g) are performed sequentially; and (iii) step (g) is performed after any of steps (a) to (f).

17 . Method according to claim 15 , further comprising the steps of
(h) perform a statistics determining the stability of the array and its individual elements by analyzing the voltage readings obtained in claim 15 (b) by using the controller; and (i) if at least one unstable conductive element is identified, selectively apply current with selected polarity to such at least one deviating conductive element for electrochemical scrubbing and coating.

Assignees

• Merck Patent Gmbh

Inventors

• Lepple-Wienhues Albrecht

Classifications

• G01N33/4836

  using multielectrode arrays · CPC title

• G01N27/401

  Salt-bridge leaks; Liquid junctions · CPC title

• G01N27/4163

  checking the operation of, or calibrating, the measuring apparatus (G01N27/3274, G01N27/4175 and G01N33/0006 take precedence) · CPC title

• G01N27/414

  Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS · CPC title

• G01N27/38 Primary

  Cleaning of electrodes · CPC title