# US 11,029,280 B2 · Alkalinity sensor

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,029,280 B2
- Document ID: US11029280B2
- Status: Granted
- Kind: B2
- Application number: 15/745,586
- Filed: 2017-06-22
- Published: 2018-08-09
- Granted: 2021-06-08
- Earliest claimed: 2016-06-23
- Assignees: Hach Company
- Applicants: Hach Company
- Inventors: Dan Kroll; Corey Salzer
- Web page: https://patentgrep.com/patent/US11029280B2

## CPC

- G01N 27/44: using electrolysis to generate a reagent, e.g. for titration
- G01N 27/302: {pH sensitive, e.g. quinhydron, antimony or hydrogen electrodes (ion selective electrodes G01N27/333, glass electrodes G01N27/36)}
- G01N 27/308: {at least partially made of carbon}
- G01N 27/4167: {pH (electrodes therefor G01N27/302, G01N27/36)}
- G01N 27/423: {Coulometry}
- G01N 31/164: {by electrical or electrochemical means}
- G01N 33/182: {Specific anions in water}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

An embodiment provides a method for determining the alkalinity of an aqueous sample using an alkalinity sensor, including: monitoring the pH of an aqueous sample using a pH sensor in a sample cell, the pH sensor including a pH sensor electrode made of boron-doped diamond; generating hydronium ions, using a hydronium generator, in the aqueous sample in the sample cell, the hydronium generator including a hydronium-generating electrode; changing the pH of the aqueous sample by causing the hydronium generator to generate an amount of hydronium ions in the aqueous sample; quantifying and converting a current or charge to the number of hydronium ions produced to an end point of the electrochemical titration, the end point correlating to the alkalinity of a sample; and analyzing the alkalinity of the aqueous sample based on the generated amount of hydronium ions and the resulting change in pH monitored by the pH sensor.

## Claims

### Claim 1

A method for determining the alkalinity of an aqueous sample using an alkalinity sensor, comprising:
monitoring the pH of an aqueous sample using a pH sensor in a sample cell, the pH sensor including a pH sensor electrode made of boron-doped diamond;
controlling, using a peristaltic pump, a flow of the aqueous sample between the pH sensor and a boron-doped diamond hydronium generator, wherein the pH sensor and the boron-doped diamond hydronium generator each form a portion of a lumen to form a path for the flow of the aqueous sample;
generating hydronium ions, using the boron-doped diamond hydronium generator, in the aqueous sample in the sample cell, the boron-doped diamond hydronium generator including a boron-doped diamond hydronium-generating electrode, wherein the alkalinity sensor comprises at least one counter electrode and at least one reference electrode separated from the sample cell by a restrictive conduit, wherein the at least one counter electrode and the at least one reference electrode are placed at a position relative to the aqueous sample from the group consisting of: fore and aft;
changing the pH of the aqueous sample by causing the boron-doped diamond hydronium generator to generate a number of hydronium ions in the aqueous sample;
quantifying and converting a current or charge to the number of hydronium ions produced to an end point of an electrochemical titration, the end point correlating to the alkalinity of the aqueous sample; and
analyzing the alkalinity of the aqueous sample based on the quantified number of hydronium ions and the resulting change in pH monitored by the pH sensor.

### Claim 2 (depends on 1)

The method of claim 1, wherein the hydronium-generating electrode and the pH sensor electrode are on a unitary substrate.

### Claim 3 (depends on 1)

The method of claim 1, wherein the hydronium-generating electrode and the pH sensor electrode comprise boron-doped diamond on a single substrate.

### Claim 4 (depends on 1)

The method of claim 1, wherein the pH sensor electrode comprises a disc of boron-doped diamond and the hydronium-generating electrode comprises a plate spaced apart from the pH sensor.

### Claim 5 (depends on 1)

The method of claim 1, wherein the pH sensor electrode comprises a disc of boron-doped diamond and the hydronium-generating electrode comprises an open ring surrounding the pH sensor.

### Claim 6 (depends on 1)

The method of claim 1, wherein the pH sensor electrode comprises a first plate of boron-doped diamond and the hydronium-generating electrode comprises a second plate of boron-doped diamond spaced apart from the first plate.

### Claim 7 (depends on 1)

The method of claim 1, wherein the hydronium-generating electrode comprises a plate having an aperture and the pH sensor electrode is located within the aperture.

### Claim 8 (depends on 1)

The method of claim 1, wherein the boron-doped diamond hydronium generator has more than one hydronium-generating electrode.

### Claim 9 (depends on 1)

The method of claim 1, wherein the pH sensor electrode, the boron-doped diamond hydronium generator and a controller are part of a potentiostat and wherein the pH sensor electrode is a first working electrode of a bipotentiostat and the hydronium generating electrode is a second working electrode of the bipotentiostat.