Indigo indicator detection of ozone

Abstract

One embodiment provides a method for measuring ozone in a sample, the method comprising: introducing an indigo-based indicator into the sample, where the sample contains an amount of ozone, and the introduction causes a fluorescence change in the solution; and measuring the amount of ozone in the sample by measuring a change in the fluorescence intensity. Other aspects are described and claimed.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Patent Application Serial No. 18 / 060,181, entitled "Detection of Ozone by Indigo - based Indicators", filed on November 30, 2022, the content of which is incorporated herein by reference. Background Art

[0003] This application generally relates to measuring ozone in aqueous or liquid samples, and more particularly to measuring ozone using indigo - based indicators.

[0004] Ensuring water quality is crucial in various industries such as pharmaceuticals and other manufacturing fields. Additionally, ensuring water quality is crucial for the health and well - being of humans, animals, and plants that depend on water for survival. One element that is commonly measured is ozone. Ozone can be controlled to make water safe for humans, animals, and aquatic organisms. Therefore, detecting the presence and concentration of ozone in water, food materials, or other liquid solutions is crucial. Summary of the Invention

[0005] Broadly speaking, one embodiment provides a method for measuring ozone in a sample, the method comprising: introducing an indigo - based indicator into the sample, wherein the sample contains a certain amount of ozone and the introduction causes a fluorescence change in the solution; and measuring the amount of ozone in the sample by measuring the change in fluorescence intensity.

[0006] Another embodiment provides a method for measuring ozone in a sample, the method comprising: introducing an indigo - based indicator into the sample, wherein the sample contains a certain amount of ozone and the introduction causes a fluorescence change in the solution; titrating the sample to a certain pH value; and measuring the amount of ozone in the sample by measuring the change in fluorescence intensity.

[0007] Another embodiment provides a measuring device for measuring ozone in a sample, the measuring device comprising: an indigo - based indicator; at least one measuring chamber; a processor; and a memory that stores instructions executable by the processor for: introducing the indigo - based indicator into the sample, wherein the sample contains a certain amount of ozone; and measuring the amount of ozone in the sample by measuring the fluorescence change of the sample.

[0008] The foregoing is a summary and, as such, may contain simplifications, generalizations, and omissions of detail; accordingly, those skilled in the art will appreciate that this summary is illustrative only and is not intended to be limiting in any way.

[0009] To better understand the embodiments and their other and further features and advantages, the following description is made with reference to the accompanying drawings. The scope of the invention will be pointed out in the appended claims. Description of the Drawings

[0010] Figure 1 A flowchart of an exemplary ozone measurement system for a sample is shown.

[0011] Figure 2 The chemical formula of an indigo-based indicator is shown.

[0012] Figure 3 An example of a reaction scheme of an indigo-based indicator for detecting ozone is shown.

[0013] Figure 4 An exemplary ozone calibration curve using an indigo-based indicator is shown.

[0014] Figure 5 An example of a computer circuit system is shown. Detailed Description of the Embodiments

[0015] It will be readily understood that, in addition to the exemplary embodiments described, the components of the embodiments generally described and illustrated in the accompanying drawings herein can be arranged and designed in a variety of different configurations. Accordingly, the following more detailed description of the exemplary embodiments shown in the drawings is not intended to limit the scope of the embodiments, but is merely representative of the exemplary embodiments.

[0016] Reference throughout this specification to "one embodiment" or "an embodiment" (etc.) means that a particular feature, structure, or characteristic described with respect to the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" etc. 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 the embodiments. However, those skilled in the relevant art will recognize that various embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail. The following description is for illustrative purposes only and only illustrates certain exemplary embodiments.

[0018] Conventional methods for measuring ozone in water may have some limitations. For example, ozone measurement can be used to determine water quality. High ozone concentrations can be harmful to animals, humans, and / or plants. Thus, as another example, a user or entity may desire that the ozone in a water body be below a specific threshold, and thus, the user can measure the ozone to determine whether the amount of ozone is below the threshold.

[0019] One standard for measuring free ozone in water is Hach's AccuVac (available from Hach Company, Loveland CO, USA (AccuVac is a registered trademark of Hach Company in countries such as the United States), which is a bleaching chemistry. These methods result in color bleaching of an amount proportional to the ozone concentration. The color obtained from the colorimetric reaction can be determined photometrically, for example, using a spectrophotometer. The amount of ozone can be determined by comparison with a similarly prepared blank vial. The absorbance of the sample reaction vial must be compared with the absorbance of the unreacted blank vial to determine the ozone concentration of the sample reaction vial.

[0020] However, existing analyte testing methods have limitations that are overcome by the methods and techniques described in more detail herein. One limitation of the prior art is that they use bleaching chemistries that are disadvantageous to some users and measurement systems. Additionally, traditional colorimetric methods require the preparation of separate "blank" vials. The additional step of preparing blank vials may introduce errors into the measurement results during blank preparation based on individual technique. Additionally, because traditional colorimetric techniques involve the bleaching of dyes, the time of preparation and the time of making the measurement may introduce variability into the sample readings. Additionally, because the technique involves the bleaching of dyes, difficulties may arise because the starting amount of the colorimetric dye may be different in both the blank and the sample vials, thereby introducing an error into the determination of the amount of analyte being tested in the sample. This error may result in false positive or false negative results.

[0021] Accordingly, one embodiment provides systems and methods for measuring ozone in a sample. A sample can be taken from a volume of liquid such as a holding tank, a water source, a food material source, a beverage source, etc. The sample can be free of other oxidants. In one embodiment, the method can detect ozone at concentrations in the range of about 0 to 1.7 ppm (parts per million). In one embodiment, the method can use fluorometry. The indicator that gives a fluorescence signal can be an indigo-based derivative. The indigo-based indicator can be indigo carmine or indigo-5,5'-disulfonic acid disodium salt. In one embodiment, the fluorescence can be related to the detection of ozone. In one embodiment, the fluorescence intensity or fluorescence change can be related to the ozone in the sample. A buffer can be added, such as a phosphate buffer. In one embodiment, the pH of the solution can be adjusted to activate the reporter molecule or the indicator molecule. The pH can be adjusted to above pH 7.0.

[0022] The illustrated exemplary embodiments will be best understood by reference to the accompanying drawings. The following description is for illustrative purposes only and illustrates certain exemplary embodiments.

[0023] Reference Figure 1 , an exemplary system and method for detecting ozone in a sample are shown. In one embodiment, an indigo-based indicator can be prepared. The indigo-based indicator can be indigo-5,5'-disulfonic acid disodium salt or indigo carmine. The indigo carmine indicator can be introduced into a sample containing ozone. In one embodiment, the indigo carmine indicator can cause a change in the fluorescence intensity of the indicator in the presence of ozone. The change in fluorescence intensity can be related to the concentration of ozone in the solution or sample.

[0024] At 101, in one embodiment, an indigo-based can be prepared. The indigo-based indicator can be indigo-5,5'-disulfonic acid disodium salt or indigo carmine (see Figure 2 ). Referring to Figure 3 , an exemplary reaction of the indigo carmine indicator is shown. In one embodiment, the indigo carmine indicator can detect ozone in the range of 0 to 1.7 mg / L. This range is exemplary; for example, the range can be determined based on the need to control ozone to a level suitable for water treatment.

[0025] At 102, in one embodiment, indigo carmine indicator can be introduced into a sample. The sample can contain ozone or a certain amount of ozone. The solution can be the sample, which can include samples from natural water bodies, holding tanks, processing tanks, pipelines, water systems, a certain volume of liquid for food preparation, etc. The solution can be in a continuous flow state, a static volume of liquid, or any combination thereof. In one embodiment, the sample can be introduced into an indigo-based indicator (e.g., the test chamber of a measuring device). Introducing the sample into the measuring device can include the user manually or using mechanical means (e.g., gravity flow, pump, pressure, fluid flow, etc.) to place or introduce the sample into the test chamber. For example, a water sample for ozone testing can be introduced into the measuring chamber or test chamber using a pump. In one embodiment, valves, etc. can control the inflow and outflow of the solution into and from one or more chambers (if any).

[0026] Additionally or alternatively, the measuring device can be present in or introduced into a certain volume of the sample. The measuring device is then exposed to the certain volume of the sample, where the measuring device can make measurements. The system can be a flow-through system in which the solution and / or reagent are automatically mixed and measured. As discussed in more detail herein, once the sample contacts the measuring system, the system can measure the ozone in the sample or the fluorescence change of the sample. In one embodiment, the measuring device can include one or more chambers in which one or more method steps can be performed.

[0027] At 103, in one embodiment, the pH of the solution can be controlled. Additionally or alternatively, ozone can be added to the solution. Ozone can be added to the sample using an ozone generator or can be from another process. In one embodiment, the presence of ozone can "turn-on" the fluorescence property of the indigo carmine indicator. For example, the pH can be adjusted or titrated to near a pH within the range of about 7.0 or higher pH values (more alkaline). The indigo carmine indicator concentration can be approximately 10 to 150 micromoles (μM). The indicator concentration can be adjusted based on the ozone concentration in the sample. In one embodiment, a buffer can be added. The buffer can be a phosphate buffer. The phosphate buffer concentration can be about 75 mM. Citrate can be added as an additive. The approximate detection range of ozone is 0 to 1.7 mg / L or ppm (parts per million).

[0028] At 104, in one embodiment, the system and method can determine whether the ozone concentration can be determined. In one embodiment, the presence of ozone in the sample can cause an increase in the fluorescence intensity of the indigo-based indicator. This increase in the fluorescence intensity of the indigo-based indicator and an example of the dose-response curve can be in Figure 4It is shown in. One embodiment of relative fluorescence units (RFU) is plotted against ozone concentration (ppm). The ozone concentrations shown are from 0 to about 1.7 ppm. The experimental conditions can include: generating ozone using an ozone generator at room temperature or cooling the sample to about 0 to 5 degrees Celsius, agitating the sample, pretreating the pipette tips by placing them into the ozonated sample, and measuring absorbance using a 10 cm cell. These conditions are exemplary and can be varied based on the conditions. In one embodiment, the indigo carmine indicator can be used at a final concentration of 10 to 150 micromoles (μM).

[0029] The measured absorbance can be related to the concentration or amount of ozone in the sample or water. This correlation can be based on the UV-Vis measurements of ozone. It can be used as a reference measurement. Then the same aliquots can be used in a 22±1 mm or 16 mm cell with a buffer and an indicator. Depending on the ozone concentration, the sample can be diluted with deionized water. The measurement can use a Hach DR1300 FL (obtainable from Hach Company, Loveland, Colorado, USA) instrument to measure the RFU value or concentration relative to the UV-Vis value. In one embodiment, the excitation wavelength can be between 320 and 385 nanometers (nm), preferably 365 nm. In one embodiment, the emission wavelength can be 420 to 470 nm, preferably 450 nm. In one embodiment, an excitation LED at 365 nm and a PMT detector with a 450 nm emission filter can be used to measure the fluorescence intensity. The fluorescence intensity is proportional to the ozone concentration. In one embodiment, a quartz cuvette may not be required. In one embodiment, a glass or methacrylate cuvette can be used.

[0030] A phosphate buffer can be added. In one embodiment, citrate can be added as an additive. The concentration of citrate can be 15 mM. Citrate can prevent the formation of metal phosphates by complexation.

[0031] Thus, the fluorescence intensity of a solution containing ozone can be related to the intensity or the change in intensity of the sample or aqueous solution. Fluorescence curves can be generated for various concentrations, for different indigo-based indicators, for any different conditions that may affect the absorption or fluorescence values (e.g., temperature, sample content, turbidity, viscosity, measurement device, aqueous sample chamber, etc.), etc.

[0032] Alternatively or additionally, ozone measurements can be made at user-set periodic intervals or at a pre-programmed frequency in the device. Real-time data can be obtained through the measurements of the device, and little manual participation is required during the measurement process. It may be necessary to clean the fluorescence measurement chamber at unspecified time intervals. A programmed calibration curve can be input into the device.

[0033] A chamber, container, cell, cavity, etc. can hold a sample, at least one indigo carmine indicator, and related reagents such as buffers and / or additives. The device can include one or more reagent bottles containing the necessary reagents. The reagents contained in one or more bottles can be pump-fed or gravity-fed. The flow of the reagents can be metered to ensure proper volume delivery to the measurement cell. The sample can be fed through a pressurized inlet, container, etc. The sample can be introduced into the measurement chamber by pump-feeding or gravity-feeding. The sampling device can be in series or parallel with the water stream. The device can have a system to ensure proper mixing of the aqueous sample, indigo carmine indicator, and related reagents.

[0034] The fluorescence intensity or ozone concentration can be an output result in the form of a display, print, storage, audio, tactile feedback, etc. on the device. Alternatively or additionally, the output result can be sent to another device via wired, wireless, fiber optic, Bluetooth®, near field communication, etc. One embodiment can use an alarm to warn of measurement results or concentrations outside the acceptable level. One embodiment can use the system to shut off the water output, or divert water from a source with unacceptable analyte levels. For example, an analyte measurement device can use a relay connected to an electric valve, etc.

[0035] At 106, in one embodiment, if the ozone concentration cannot be determined, the system can continue to measure the ozone, the change in fluorescence intensity, and / or the fluorescence intensity. Additionally or alternatively, the system can output an alarm, record an event, etc.

[0036] If the ozone concentration can be determined, at 105, the system can provide the measurement result of the ozone concentration. The system can be connected to a communication network. The system can issue an alarm to the user or the network. This alarm can be issued whether or not the ozone measurement result is determined. The alarm can be in the form of sound, vision, data, storing data to a memory device, sending an output through a connected system or a wireless system, a printout, etc. The system can record information such as the measurement location, calibration actions, geographical location, time, date, the number of measurement cycles, etc. The alarm or log can be automated, meaning the system can automatically output whether calibration is needed. The system can also have related alarms, limits, or preset thresholds. For example, if the ozone concentration reaches the threshold. The alarm or log can be analyzed in real time, stored for later use, or any combination of these.

[0037] Accordingly, the various embodiments described herein represent a technological improvement over conventional ozone measurement techniques. Using the techniques described herein, one embodiment can use indigo carmine indicator to measure ozone in a solution. This is in contrast to methods having the limitations described above. Such techniques provide a faster and more accurate method for measuring ozone in an aqueous or liquid solution. Accordingly, the various embodiments described herein represent a technological improvement for accurate ozone measurement in a sample. Using the techniques described herein, one embodiment can use methods and apparatus for measuring ozone concentration. This is in contrast to conventional methods having the limitations described above.

[0038] Although various other circuits, circuit systems, or components may be used in an information processing device, with respect to an instrument for ozone measurement according to any one of the embodiments described herein, Figure 5 an example is shown in FIG. The device circuit system 10' may include a measurement system based on a created chip design, e.g., a specific computing platform (e.g., mobile computing, desktop computing, etc.). Software and one or more processors are combined in a single chip 11'. It is well known in the art that a processor includes internal arithmetic units, registers, caches, buses, I / O ports, etc. The internal buses, etc. depend on different vendors, but essentially all peripherals (12') can be connected to the single chip 11'. The circuit system 10' combines a processor, memory control, and an I / O controller hub into a single chip 11'. Additionally, this type of system 10' generally does not use SATA or PCI or LPC. For example, common interfaces include SDIO and I2C.

[0039] There are one or more power management chips 13', e.g., a battery management unit (BMU), which manages power supplied, for example, by a rechargeable battery 14' (which can be recharged by connecting to a power source (not shown)). In at least one design, a single chip such as 11' provides a BIOS-like function and DRAM memory.

[0040] The system 10' typically includes one or more of a WWAN transceiver 15' and a WLAN transceiver 16' for connecting to various networks such as a radio communication network and wireless Internet devices (e.g., access points). Additionally, devices 12' are typically included, e.g., transmit and receive antennas, oscillators, PLLs, etc. The system 10' includes input / output devices 17' for data input and display / rendering (e.g., a computing location that is easily accessible to a user and located away from the single beam system). The system 10' typically also includes various memory devices, such as flash memory 18' and SDRAM 19'.

[0041] As can be understood from the foregoing, the electronic components of one or more systems or devices may include, but are not limited to: at least one processing unit, a memory, and a communication bus or communication device that connects the various elements (including the memory) to one or more processors. The system or device may include or access various device-readable media. The system memory may include device-readable storage media in the form of volatile and / or non-volatile memory (such as read-only memory (ROM) and / or random access memory (RAM)). By way of example and not limitation, the system memory may also include an operating system, application programs, other program modules, and program data. The disclosed system may be used in one embodiment to perform ozone measurements on a sample.

[0042] Those skilled in the art will appreciate that aspects may be implemented as a system, method, or device program product. Accordingly, aspects may take the form of an entirely hardware embodiment, an embodiment including software, which may herein be collectively referred to as "circuitry", "module", or "system". Additionally, aspects may take the form of a device program product embodied in one or more device-readable media having device-readable program code therein.

[0043] It should be noted that the various functions described herein may be implemented using instructions stored on a device-readable storage medium (such as a non-signal storage device), where the instructions are executed by a processor. In the context of this document, the storage device is not a signal, and "non-transitory" includes all media other than signal media.

[0044] The program code for implementing the operations may be written in any combination of one or more programming languages. The program code may execute entirely on a single device, partially on a single device, as a stand-alone software package, partially on a single device and partially on another device, or entirely on other devices. In some cases, the devices may be connected by any type of connection or network (including a local area network (LAN) or a wide area network (WAN)), or may be connected through other devices (e.g., via the Internet using an Internet service provider), via a wireless connection (e.g., near field communication), or via a hardwired connection (such as via a USB connection).

[0045] Exemplary embodiments are described herein with reference to the accompanying drawings, which illustrate exemplary methods, devices, and products according to the various exemplary embodiments. It is to be understood that the acts and functions may be at least partially implemented by program instructions. These program instructions may be provided to a processor of a device (such as a handheld measurement device) or other programmable data processing device, thereby producing a machine such that the instructions executed by the processor of the device implement the specified functions / acts.

[0046] Note that the values provided herein are to be interpreted as including equivalent values represented by the use of the term "about". Equivalent values will be apparent to those of ordinary skill in the art, but will include at least values obtained by ordinary rounding of the last significant digit.

[0047] This disclosure is provided for illustrative and descriptive purposes, but is not intended to be exhaustive or limiting. Numerous changes and variations will be apparent to those of ordinary skill in the art. Exemplary embodiments are selected and described to explain the principles and practical applications, and to enable those of ordinary skill in the art to understand the disclosure of various embodiments with various changes suitable for the particular purposes contemplated.

[0048] Accordingly, although the exemplary embodiments illustrated have been described herein with reference to the accompanying drawings, it is to be understood that this description is not limiting, and that various other changes and modifications may be effected therein by those of ordinary skill in the art without departing from the scope and spirit of the disclosure.

Claims

1. A method for measuring ozone in a sample, the method comprises: introducing an indigo-based indicator into the sample, wherein the sample contains a certain amount of ozone, and the introduction causes a fluorescence change in the solution; and measuring the amount of ozone in the sample by measuring the change in fluorescence intensity.

2. The method according to claim 1, wherein the indigo-based indicator is selected from the group consisting of sodium indigo-5,5'-disulfonate and indigo carmine.

3. The method according to claim 1, the method further comprises: titrating the sample to a pH of about 7.

0.

4. The method according to claim 1, the method further comprises: titrating the sample to a pH greater than 7.

0.

5. The method according to claim 1, the method further comprises: adding a phosphate buffer.

6. The method according to claim 1, wherein the amount of ozone is in the range of 0 to 1.7 mg / L.

7. The method according to claim 1, wherein the fluorescence intensity is related to the concentration of ozone in the sample.

8. The method according to claim 1, wherein the measurement uses an excitation wavelength of 320 to 370 nm and an emission wavelength of 420 to 470 nm.

9. The method according to claim 1, wherein the measurement is carried out in a cuvette made of a material selected from the group consisting of glass and methacrylate.

10. The method according to claim 1, wherein the sample comprises water from a beverage material system.

11. A method for measuring ozone in a sample, the method comprises: introducing an indigo-based indicator into the sample, wherein the sample contains a certain amount of ozone, and the introduction causes a fluorescence change in the solution; titrating the sample to a certain pH value; and measuring the amount of ozone in the sample by measuring the change in fluorescence intensity.

12. The method according to claim 11, wherein the indigo-based indicator is selected from the group consisting of sodium indigo-5,5'-disulfonate and indigo carmine.

13. The method according to claim 11, wherein the pH value comprises a pH of about 7.

0.

14. The method according to claim 11, wherein the pH value comprises a pH greater than 7.

0.

15. The method according to claim 11, the method further comprises: adding a phosphate buffer.

16. The method according to claim 11, wherein the amount of ozone is in the range of 0 to 1.7 mg / L.

17. The method according to claim 11, wherein the fluorescence intensity is related to the concentration of ozone in the sample.

18. The method according to claim 11, wherein the measurement uses an excitation wavelength of 320 to 370 nm and an emission wavelength of 420 to 470 nm.

19. The method according to claim 11, wherein the measurement is carried out in a cuvette made of a material selected from the group consisting of glass and methacrylate.

20. A measuring device for measuring ozone in a sample, the measuring device comprises: an indigo-based indicator; at least one measurement chamber; a processor; and A memory that stores instructions executable by the processor for: introducing the indigo-based indicator into a sample, wherein the sample contains a certain amount of ozone; and measuring the amount of ozone in the sample by measuring a change in fluorescence of the sample.

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