Method and apparatus for detecting amines and ammonia by fluorescence
AssigneeNalco Chemical Company
InventorsMartin R. Godfrey, Donald E. Govoni, Linda M. Link
Life of this patent
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Abstract
Primary amines, ammonia, or mixtures thereof can be detected using a reagent comprising from about 650 ppm to about 25 percent by weight of phthalic dicarboxyaldehyde; from about 74 to about 99.88 percent by weight of an alkali metal borate; and, from about 550 ppm to about 22 percent by weight of a nucleophile.
Claims18
A method for determining the presence and concentration of primary amines, ammonia, or mixtures thereof in an aqueous fluid comprising the steps of:
- a. obtaining a sample of an aqueous fluid;
- b. adding to the fluid sample a reagent comprising:
- i. from about 650 ppm to about 25 percent by weight of phthalic dicarboxyaldehyde;
- ii. from about 74 to about 99.88 percent by weight of an alkali metal borate;
- and,
- iii. from about 550 ppm to about 22 percent by weight of a nucleophile, said nucleophile being thiolglycolic acid;
- in an amount sufficient to react with all of the primary amines, ammonia, or mixtures thereof contained in the fluid sample;
- c. measuring the fluorescence emission of the fluid sample containing the reagent at a known set of excitation and emission wavelengths;
- d. comparing the fluorescence emission measured in step c. with a calibration curve obtained from fluorescence emissions at the same wavelength from at least two test fluid samples containing differing known amounts of primary amines, ammonia, or mixtures thereof;
- and then,
- e. determining the presence and concentration of primary amines, ammonia, or mixtures thereof in the fluid.
A method for determining the presence and concentration of primary amines, ammonia, or mixtures thereof in an aqueous fluid comprising the steps of:
- a. obtaining a sample of an aqueous fluid;
- b. adding to the fluid sample a reagent comprising:
- i. from about 12 ppm to about 3.3 percent by weight of phthalic dicarboxyaldehyde;
- ii. from about 0 to about 50 percent by weight of an alcohol selected from the group consisting of;
- methanol;
- ethanol;
- propanol;
- and, isopropyl alcohol;
- iii. from about 35 ppm to about 2 percent by weight of an alkali metal borate;
- iv. from about 10 ppm to about 5.4 percent by weight of a nucleophile, said nucleophile being thiolglycolic acid;
- v. the balance being water,
- in an amount sufficient to react with all of the primary amines, ammonia, or mixtures thereof contained in the fluid sample;
- c. measuring the fluorescence emission of the fluid sample containing the reagent at a known set of excitation and emission wavelengths;
- d. comparing the fluorescence emission measured in step c. with a calibration curve obtained from fluorescence emissions at the same wavelength from at least two test fluid samples containing differing known amounts of primary amines, ammonia, or mixtures thereof;
- and then,
- e. determining the presence and concentration of primary amines, ammonia, or mixtures thereof in the fluid.
A method of monitoring and controlling feed of primary amines, ammonia, or a mixture thereof to an aqueous fluid system by monitoring the concentration of the primary amines, ammonia, or a mixture thereof by fluorescence analysis comprising the steps of:
- a. obtaining a sample of an aqueous fluid;
- b. adding to the fluid sample an effective amount of a reagent comprising:
- i. from about 650 ppm to about 25 percent by weight of phthalic dicarboxyaldehyde;
- ii. from about 74 to about 99.88 percent by weight of an alkali metal borate;
- and,
- iii. from about 550 ppm to about 22 percent by weight of a nucleophile, said nucleophile being thiolglycolic acid
- in an amount sufficient to react with all of the primary amine, ammonia, or mixtures thereof contained in the fluid sample;
- c. measuring the fluorescence emission of the fluid sample containing the reagent by fluorescence analysis of the fluid sample;
- d. determining the fluorescence emission magnitude at least one fluorescence emission wavelength;
- e. comparing the fluorescence emission magnitude measured in step d. with the fluorescence emission magnitude obtained at the wavelength determined in step c. from at least two test fluid samples containing differing known amounts of primary amines, ammonia, or mixtures thereof;
- f. determining the concentration of primary amines, ammonia, or mixtures thereof in the fluid;
- and then,
- g. controlling the concentration of the primary amines, ammonia, or mixtures thereof in the fluid,
- thereby monitoring and controlling the concentration of the primary amines, ammonia, or mixtures thereof within a predetermined range in the fluid system.
Dependencies are inferred from the claim text.