# US 4,393,142 A · Assay method and reagent for the determination of chloride

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

- Number: US 4,393,142 A
- Document ID: US4393142A
- Status: Granted
- Kind: A
- Application number: 06/344,331
- Filed: 1982-02-01
- Granted: 1983-07-12
- Earliest claimed: 1982-02-01
- Assignees: American Monitor Corporation
- Inventors: Thomas W. Stephens
- Web page: https://patentgrep.com/patent/US4393142A

## CPC

- G01N 33/84: involving inorganic compounds or pH
- G01N 33/52: Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper {and including single- and multilayer analytical elements (immunological elements G01N33/54386; involving labelled immunochemicals G01N33/58; for haemoglobin or occult blood G01N33/72)}
- G01N 2800/04: Endocrine or metabolic disorders
- Y10T 436/193333: In aqueous solution
- 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)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A colorimetric assay method and reagent composition for the direct, quantitative determination of chloride in fluids which may be performed directly on non-deproteinized samples and which utilizes a reagent comprised of 2,4,6-tripyridyl-s-triazine, mercuric ions, ferrous ions, and a sulfate salt in a sulfate or sulfonate buffer at a selected pH in the range of about 1.5 to 3.0.

## Claims

### Claim 1

A reagent composition for the determination of chloride in a protein-containing fluid, comprised of:
(a) 2,4,6-tripyridyl-s-triazine;
(b) mercuric ions;
(c) ferrous ions;
(d) at least one salt selected from the group consisting of sodium sulfate, manganese sulfate, magnesium sulfate, and cupric sulfate; and
(e) a buffer selected from the group consisting of sulfuric acid and toluene sulfonate.

### Claim 2 (depends on 1)

A composition as recited in claim 1, wherein the pH is between about 1.5 and 3.0.

### Claim 3 (depends on 1)

A composition as recited in claim 1, wherein the pH is between about 1.6 and 2.4.

### Claim 4

A method for the determination of chloride in a protein-containing fluid, comprising the steps of:
(a) combining a sample of said fluid with a reagent to form a solution, said reagent comprising:
(i) 2,4,6-tripyridyl-s-triazine,
(ii) mercuric ions,
(iii) ferrous ions,
(iv) at least one salt selected from the group consisting of sodium sulfate, manganese sulfate, magnesium sulfate, and cupric sulfate; and
(v) a buffer selected from the group consisting of sulfuric acid and toluene sulfonate;
(b) measuring the absorbance of said solution; and
(c) comparing the absorbance of said solution with the absorbance obtained on solutions containing known amounts of chloride.

### Claim 5 (depends on 4)

A method as recited in claim 4, wherein the pH of said reagent is between about 1.5 and 3.0.

### Claim 6 (depends on 4)

A method as recited in claim 4, wherein the pH of said reagent is between about 1.6 and 2.4.

### Claim 7 (depends on 4)

A method as recited in claim 4, wherein the absorbance of said solution is measured at a wavelength between about 580 to 630 nm.

### Claim 8

A test kit for the determination of chloride in protein-containing fluid samples, containing a reagent which comprises:
(a) 2,4,6-tripyridyl-s-triazine;
(b) mercuric ions;
(c) ferrous ions;
(d) at least one salt selected from the group consisting of sodium sulfate, manganese sulfate, magnesium sulfate, and cupric sulfate; and
(e) a buffer selected from the group consisting of sulfuric acid and toluene sulfonate.