Methods for detecting film-forming amines in water

Patent metadata

Field	Value
Publication number	US-11016027-B2
Application number	US-201816342855-A
Country	US
Kind code	B2
Filing date	Jul 30, 2018
Priority date	Jul 28, 2017
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

Methods and systems for detecting and quantifying film forming amines in water systems are described. Water containing a film forming amine is combined with a fluorescent dye, the pH of the water is reduced, and then the fluorescence signal of the fluorescent dye is measured. The fluorescence signal is indicative of the amount of film forming amine in the water, and can be used to quantify the amount of film forming amine and control the amount of film forming amine that is introduced into the water system.

First claim

What is claimed is:

1. A method of detecting film forming amine that is present in water, the method comprising (i) combining the water, an anionic fluorescent dye, and at least one of an acidic buffer and an acid, and (ii) then measuring a fluorescence signal of the fluorescent dye, wherein the film forming amine includes at least one primary amine group that associates with the anionic fluorescent dye and wherein the primary amine group associates with the anionic fluorescent dye, which reduces the fluorescent emission signal of the anionic fluorescent dye.

2. The method of claim 1 , further comprising determining the amount of film forming amine in the water based on the measured fluorescence signal.

3. The method of claim 1 , wherein the film forming amine is present in the water in an amount that is in the range of 0.05 ppm to 20 ppm.

4. The method of claim 1 , wherein the acidic buffer is combined in sufficient amounts with the water so that the pH of the water is in the range of 4 to 7.

5. The method of claim 1 , wherein the water further includes a neutralizing amine.

6. The method of claim 5 , wherein the neutralizing amine is present in the water in an amount that is in the range of from 1 to 30 ppm.

7. The method of claim 1 , wherein the acidic buffer is combined so that is present at a concentration in the range of from 80-500 ppm.

8. The method of claim 1 , wherein the anionic fluorescent dye is 1,3,6,8-Pyrenetetrasulfonic acid and the fluorescent signal is measured between 3 and 5 minutes from the combining step.

9. The method of claim 1 , wherein the anionic fluorescent dye and the acidic buffer are added to the water as a mixture.

10. A method comprising: (i) combining water that contains a film forming amine with an anionic fluorescent dye; (ii) reducing the pH of the water; and (iii) then measuring a fluorescent signal of the fluorescent dye, wherein the film forming amine includes at least one primary amine group that associates with the anionic fluorescent dye and wherein the primary amine group associates with the anionic fluorescent dye, which reduces the fluorescent emission signal of the anionic fluorescent dye.

11. The method of claim 10 , wherein the pH of the water is reduced by combining the water with an acidic buffer.

12. The method of claim 10 , wherein the pH of the water is reduced to a pH that is at least 2 pH values below the pKa of the film forming amine.

13. The method of claim 1 , wherein the film forming amine includes a hydrocarbon group with 5 to 40 carbon atoms.

Assignees

• Chemtreat Inc

Inventors

• STUART Dale
• Kalakodimi Rajendra Prasad

Classifications

• C23F11/00

  Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent (adding inhibitors to mineral oil, fuels, or lubricants C10; adding inhibitors to pickling solutions C23G) · CPC title

• G01N21/77 Primary

  by observing the effect on a chemical indicator · CPC title

• G01N2021/7786

  Fluorescence · CPC title

• G01N21/6428

  Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" (in vivo A61B5/00; immunoassay G01N33/53) · CPC title

• G01N21/645

  Specially adapted constructive features of fluorimeters · CPC title