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EP-4735871-A1 - MITIGATION OF FREE CHLORINE INTERFERENCE FOR OZONE DETECTION USING AN INDIGO-BASED INDICATOR

EP4735871A1EP 4735871 A1EP4735871 A1EP 4735871A1EP-4735871-A1

Abstract

An embodiment provides a method for measuring ozone in a sample, including: introducing an indigo-based indicator to a sample, wherein the sample contains an amount of ozone and the introducing causes a change in fluorescence intensity of the solution; introducing an ammonium salt to the sample; and measuring the amount of ozone in the sample by measuring the change in intensity of the fluorescence.

Inventors

  • DAS, AMIT

Assignees

  • Hach Company

Dates

Publication Date
20260506
Application Date
20240626

Claims (20)

  1. 1. A method for measuring ozone in a sample, comprising: introducing an indigo-based indicator to a sample, wherein the sample contains an amount of ozone and the introducing causes a change in fluorescence intensity of the solution; introducing an ammonium salt to the sample; and measuring the amount of ozone in the sample by measuring the change in intensity of the fluorescence.
  2. 2. The method of claim 1 , wherein the indigo-based indicator is selected from the group consisting of indigo-5, 5'-disulfonate sodium salt and indigo carmine.
  3. 3. The method of claim 1 , further comprising adjusting the sample to a pH of about 7.0.
  4. 4. The method of claim 1 , further comprising adjusting the sample to a pH of greater than 7.0.
  5. 5. The method of claim 1, further comprising adding a phosphate buffer.
  6. 6. The method of claim 1, wherein the amount of ozone is in the range of 0 - 2.1 mg/L.
  7. 7. The method of claim 1, wherein the fluorescence intensity is correlated to a concentration of the ozone in the sample.
  8. 8. The method of claim 1, wherein the measuring uses an excitation wavelength between 320 and 370 nm and an emission wavelength between 420 and 470 nm.
  9. 9. The method of claim 1, wherein measuring occurs in a cuvette of a material selected from the group consisting of glass, polymethyl methacrylate, and acrylic.
  10. 10. The method of claim 1, wherein the sample comprises water from a beverage material system.
  11. 11 A method for measuring ozone in a sample, comprising: introducing an indigo-based indicator to a sample, wherein the sample contains an amount of ozone and the introducing causes a change in fluorescence intensity of the solution; introducing an ammonium salt to the sample; adjusting the sample to a pH value; and measuring the amount of ozone in the sample by measuring the change in intensity of the fluorescence.
  12. 12. The method of claim 11 , wherein the indigo-based indicator is selected from the group consisting of indigo-5, 5 -disulfonate sodium salt and indigo carmine.
  13. 13. The method of claim 11, wherein the pH value comprises a pH of about 7.0.
  14. 14. The method of claim 11 , wherein the pH value comprises a pH of greater than 7.0.
  15. 15. The method of claim 11, further comprising adding a phosphate buffer.
  16. 16. The method of claim 11 , wherein the amount of ozone is in the range of 0 - 2.1 mg/L.
  17. 17. The method of claim 11, wherein the fluorescence intensity is correlated to a concentration of the ozone in the sample.
  18. 18. The method of claim 11 , wherein the measuring uses an excitation wavelength between 320 and 370 nm and an emission wavelength between 420 and 470 nm.
  19. 19. The method of claim 11, wherein measuring occurs in a cuvette of a material selected from the group consisting of glass, polymethyl methacrylate, and acrylic.
  20. 20. A measurement device which measures ozone in a sample, comprising: an indigo-based indicator; at least one measurement chamber; a processor; and a memory storing instructions executable by the processor to: introduce the indigo carmine indicator to a sample, wherein the sample contains an amount of ozone; introduce an ammonium salt to the sample; and measure the amount of ozone in the sample by measuring a change in fluorescence intensity of the sample.

Description

MITIGATION OF FREE CHLORINE INTERFERENCE FOR OZONE DETECTION USING AN INDIGO-BASED INDICATOR CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims priority to U.S. Patent Application Serial No. 18/342,216, filed on June 27, 2023, and entitled “MITIGATION OF FREE CI ILORINE INTERFERENCE FOR OZONE DETECTION USING AN INDIGO-BASED INDICATOR,” the contents of which are incorporated by reference herein. BACKGROUND [0002] This application relates generally to measuring ozone in aqueous or liquid samples, and, more particularly, to the measurement of ozone using an indigo-based indicator. [0003] Ensuring water quality is critical in a number of industries such as pharmaceuticals and other manufacturing fields. Additionally, ensuring water quality is critical to the health and well-being of humans, animals, and plants which are reliant on the water for survival. One element that is typically measured is ozone. Ozone may be controlled to make water safe for humans, animals, and aquatic life. Therefore, detecting the presence and concentration of ozone in water, food materials, or other liquid solutions is vital. BRIEF SUMMARY [0004] In summary, one embodiment provides a method for measuring ozone in a sample, comprising: introducing an indigo-based indicator to a sample, wherein the sample contains an amount of ozone and the introducing causes a change in fluorescence intensity of the solution; introducing an ammonium salt to the sample; and measuring the amount of ozone in the sample by measuring the change in intensity of the fluorescence. [0005] Another embodiment provides a method for measuring ozone in a sample, comprising: introducing an indigo-based indicator to a sample, wherein the sample contains an amount of ozone and the introducing causes a change in fluorescence intensity of the solution; introducing an ammonium salt to the sample; adjusting the sample to a pH value; and measuring the amount of ozone in the sample by measuring the change in intensity of the fluorescence. [0006] A further embodiment provides a measurement device which measures ozone in a sample, comprising: an indigo-based indicator, at least one measurement chamber; a processor; and a memory storing instructions executable by the processor to: introduce the indigo carmine indicator to a sample, wherein the sample contains an amount of ozone; introduce an ammonium salt to the sample; and measure the amount of ozone in the sample by measuring a change in fluorescence intensity of the sample. [0007] The foregoing is a summary and thus may contain simplifications, generalizations, and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. [0008] For a better understanding of the embodiments, together with other and further features and advantages thereof, reference is made to the following description, taken in conjunction with the accompanying drawings. The scope of the invention will be pointed out in the appended claims. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0009] FIG. 1 illustrates a flow diagram of an example ozone measuring system for a sample. [0010] FIG. 2 illustrates a chemical formula of an indigo-based indicator. [0011] FIG. 3 illustrates a reaction scheme example of an indigo- based indicator for detection of ozone. [0012] FIG. 4 illustrates example data of mitigation of ftee chlorine in a sample during ozone measurement. [0013] FIG. 5 illustrates an example ozone calibration curve using an indigo-based indicator in the presence of an ammonium salt. [0014] FIG. 6 illustrates an example of computer circuitry. DETAILED DESCRIPTION [0015] It will be readily understood that the components of the embodiments, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations in addition to the described example embodiments. Thus, the following more detailed description of the example embodiments, as represented in the figures, is not intended to limit the scope of the embodiments, as claimed, but is merely representative of example embodiments. [0016] Reference throughout this specification to “one embodiment” or “an embodiment” (or the like) means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” or the like in various places throughout this specification are not necessarily all referring to the same embodiment. [0017] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that the various embodiments can be