Zinc measurement
The method of measuring zinc using sulfonic acid indicators via fluorescence solves the problems of interference and harmful reagents in existing zinc measurement technologies, enabling efficient and accurate measurement of low-concentration zinc while reducing environmental risks and costs.
Patent Information
- Application Number
- CN202511865700.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2020-05-26
- Filing Date
- 2021-05-21
- Publication Date
- 2026-03-20
AI Technical Summary
Existing technologies for measuring zinc in water or liquid solutions suffer from problems such as interference from interfering substances, the use of harmful reagents, and inaccurate measurements, especially in the measurement of low concentrations of zinc.
Zinc was measured using a fluorescence method. 8-hydroxy-5-quinoline sulfonic acid indicator was used to react with zinc, and the concentration of zinc was measured by measuring the change in fluorescence intensity. Surfactants and modifiers were added during the measurement process to reduce interference, and harmful reagents such as cyanide were avoided.
This enables more accurate and faster measurements in low-concentration zinc measurements, reducing environmental harm, lowering measurement costs, and improving measurement accuracy and efficiency.
Smart Images
Figure CN121703076A_ABST
Abstract
Description
[0001] This application is a continuation of U.S. Patent Application No. 17 / 939, 1 10, filed 5 / 21 / 2021, which is a continuation-in-part of U.S. Patent Application No. 17 / 1 1 1, 1 1 1, filed 1 1 / 1 1 / 2020, which claims priority to U.S. Provisional Patent Application No. 62 / 947, 1 1 1, filed 12 / 20 / 2019, all of which are entitled “Zinc Measurement”. TECHNICAL FIELD
[0002] The present application relates generally to measuring zinc in aqueous or liquid samples, and more particularly to measuring low zinc concentrations using a fluorescence method. BACKGROUND
[0003] Ensuring water quality is critical in a variety of industries such as pharmaceutical and other manufacturing fields. Additionally, ensuring water quality is critical to the health and well-being of humans, animals, and plants that rely on water for survival. Zinc is one element that is commonly measured. Too much zinc in water can be harmful to humans or animals. Zinc can have long term health effects and can make water less desirable for consumers or facilities. Zinc can be present from natural or human activities such as manufacturing. The measurement and mitigation of zinc can result in higher costs for water treatment. Therefore, it is critical to detect the presence and concentration of zinc in water or other liquid solutions. SUMMARY
[0004] In general, one embodiment provides a method for measuring zinc in a solution, the method comprising: preparing an indicator solution; introducing the indicator solution into a solution, wherein the solution contains an amount of zinc, and the introduction causes a change in fluorescence of the solution in response to the indicator solution reacting with the zinc; and measuring the amount of zinc in the solution by measuring the change in fluorescence intensity.
[0005] Another embodiment provides a measurement device for measuring zinc in a solution, the measurement device comprising: a processor; and a memory storing instructions executable by the processor for: preparing a sulfonic acid indicator; introducing an indicator solution into a solution, wherein the solution contains an amount of zinc, and the introduction causes a change in fluorescence of the solution in response to the indicator solution reacting with the zinc; and measuring the amount of zinc in the solution by measuring the change in fluorescence intensity.
[0006] In some preferred embodiments, the indicator solution comprises 8-hydroxy-5- quinoline sulfonic acid.
[0007] In some preferred embodiments, the indicator solution comprises a surfactant additive.
[0008] In some preferred embodiments, the solution comprises a water sample.
[0009] In some preferred embodiments, the method further comprises adding a mitigant to the solution, wherein the mitigant prevents an interferent from binding to the sulfonic acid indicator.
[0010] In some preferred embodiments, the amount of zinc comprises an amount less than 0.008 mg / L.
[0011] In some preferred embodiments, the method further comprises titrating the pH of the solution to a pH from the group consisting of: equal to pH 6, greater than pH 6, and less than pH 6.
[0012] In some preferred embodiments, the zinc binds to the sulfonic acid, causing a change in the fluorescence intensity.
[0013] In some preferred embodiments, the fluorescence intensity is proportional to the concentration of zinc in the solution.
[0014] In some preferred embodiments, the measuring comprises measuring the zinc in the solution without a cyanide compound.
[0015] Another embodiment provides a method for measuring zinc in a solution, the method comprising: preparing an indicator solution, wherein the indicator solution comprises 8-hydroxy-5-quinoline sulfonic acid; introducing the indicator solution and a surfactant into a solution, wherein the solution comprises a water sample and contains an amount of zinc, wherein the introducing causes the solution to change fluorescence in response to the indicator solution reacting with the zinc; and measuring the amount of zinc in the solution by measuring a change in fluorescence intensity, wherein the fluorescence intensity is proportional to the concentration of zinc in the solution.
[0016] The foregoing is a summary and, as such, can 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.
[0017] For a better understanding of the embodiments, and to show how they can be put into effect, reference will be made to the following description taken in conjunction with the accompanying drawings. The scope of the application will be pointed out in the appended claims. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 A flow diagram of an exemplary zinc measurement system is shown.
[0019] Figure 2 A reaction scheme of an exemplary sulfonic acid indicator for detecting zinc is shown.
[0020] Figure 3 A-B shows other examples of fluorescence intensity measurements using sulfonic acid indicators using low and high range methods.
[0021] Figure 4 An exemplary calibration curve for MDL of a measurement method is shown.
[0022] Figure 5 One instance of computer circuitry is shown. DETAILED DESCRIPTION
[0023] It will be readily understood that the components of the embodiments, as generally described and illustrated in the Figures herein, can be arranged and designed in a wide variety of different configurations. 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, but is merely representative of
[0024] Reference throughout this specification to "one embodiment" or "an embodiment" (etc.) means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" (etc.) in various places throughout this specification are not necessarily all referring to the same embodiment.
[0025] Furthermore, the described features, structures, or characteristics can 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. One skilled in the relevant art will recognize, however, that the various embodiments can 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 description below is intended only to be illustrative, and is not intended to limit the scope of the embodiments.
[0026] Zinc measurement in water or other aqueous samples or solutions is important for a variety of different reasons. For example, zinc measurement can be used to determine water quality. High concentrations of zinc can be harmful to animals, humans, and / or plants. Thus, as another example, a user or entity can desire that the zinc in a body of water be below a particular threshold, and thus, the user can measure the zinc to determine whether the amount of zinc is below the threshold. Zinc can be naturally occurring in a body of water or can be present in a body of water due to human activity such as manufacturing or storage conditions.
[0027] Conventional methods of zinc measurement and detection can have the limitations discussed herein. For example, conventional methods can use cyanide, cyclohexanone, and / or chloral hydrate. Governments can have usage restrictions or waste disposal requirements for these conventional methods. One exemplary method is the Hach 8009 - Zinon method. This method can detect zinc (Zn(II)) in the range of 0.010 - 3.0 mg / L. This method has a reaction time of approximately 3.5 minutes and uses a spectrophotometer (620 nm) or colorimeter (610 nm) for measurement. However, there are some limitations to this method. First, the presence of excess indicator can interfere with visual inspection. Second, use of this method can be problematic in the presence of interferences above given concentrations. For example, aluminum above 6 mg / L, cadmium above 0.5 mg / L, iron (III) above 7 mg / L, manganese above 5 mg / L, and nickel above 5 mg / L can interfere with correct zinc measurement. The above interference levels and types of interferences are merely illustrative and can include other concentrations and / or interferences, e.g., calcium and magnesium. Third, this method uses hazardous reagents, such as cyanide and / or cyclohexanone.
[0028] Another exemplary method for zinc measurement is the LCK 360 - 4-(2-pyridylazo)resorcinol method. This method detects zinc (Zn(II)) in the range of 0.2 - 6.0 mg / L or 0.24 - 7.2 mg / L with Crack-Set LCW 902. This method has a reaction time of approximately 3.0 minutes and uses a spectrophotometer (490 nm) for measurement. However, there are some limitations to this method. First, this method is used for very small sample volumes, such as 0.2 mL. Second, use of this method can be problematic in the presence of interferences above given concentrations, such as aluminum and manganese. Other interferences include sulfate, chloride, sodium, potassium, calcium, nitrate, magnesium, iron (II and III), tin, nickel, copper, chromium, carbonate, cobalt, and / or lead. Third, this method uses hazardous reagents, such as cyanide and / or chloral hydrate. Chloral hydrate can be particularly problematic due to being listed as a potentially controlled substance.
[0029] Because the presence of interferences can introduce significant error in zinc measurement, current methods, systems, and kits using the above methods for zinc measurement using spectrophotometric or colorimetric tests are limited. Additionally, hazardous or controlled reagents make obtaining the reagents and disposal difficult. What is needed is a method to measure zinc in a water sample with accuracy while reducing interference problems and hazardous reagents.
[0030] Accordingly, one embodiment provides systems and methods for measuring low concentrations of zinc with improved measurements in the presence of interferents and with less harmful reagents. In one embodiment, zinc in an aqueous sample or solution can be measured using a fluorescence method. The solution can contain an amount of zinc to be measured. In one embodiment, a sulfonic acid indicator can be used. In one embodiment, an 8-hydroxy-5-quinoline sulfonic acid indicator can be used. The indicator can be introduced into the solution or water sample. In one embodiment, zinc can bind with the sulfonic acid indicator causing a change in fluorescence intensity. Accordingly, a change in fluorescence intensity can occur in response to the indicator reacting with zinc. In one embodiment, the fluorescence intensity can be proportional to the concentration of zinc in the solution. In one embodiment, zinc can bind the indicator in a 1 :2 ratio (zinc:indicator). In one embodiment, the amount of zinc in the solution can be measured by measuring the change in fluorescence intensity. In one embodiment, a surfactant can be added to the solution. In one embodiment, a mitigation agent can be added to the solution to prevent interferents from binding with the indicator or to prevent zinc from binding with the indicator. The solution can be titrated. The titration can be about equal to, higher than, or lower than a pH of 6.0. In one embodiment, the pH value can be selected to minimize interference. For example, a pH about equal to or lower than a pH of 6.0 can minimize interference and a pH higher than 6.0 can be used for more pure water samples. In one embodiment, no cyanide is used in the method.
[0031] The exemplary embodiments illustrated are best understood with reference to the drawings. The following description is merely exemplary and illustrative and is not limiting.
[0032] Reference Figure 1 is shown for measuring zinc in a solution. In one embodiment, a sulfonic acid indicator can be prepared. The sulfonic acid indicator can be introduced into a solution containing zinc. In one embodiment, the sulfonic acid indicator in the presence of zinc can cause a change in fluorescence intensity of the sulfonic acid indicator and, in turn, the solution. Because different zinc concentrations result in different fluorescence intensities, the change in fluorescence intensity can be correlated to the concentration of zinc in the solution.
[0033] At 101, in one embodiment, a sulfonic acid indicator can be prepared. The sulfonic acid indicator can be an 8-hydroxy-5-quinoline sulfonic acid indicator (see Figure 2 ). In the absence of zinc, the indicator can be non-fluorescent. In the presence of zinc, the indicator can be fluorescent. Accordingly, the solution can undergo a change in fluorescence when the indicator is exposed to zinc. Reference Figure 2 is shown for an exemplary reaction of a sulfonic acid indicator.
[0034] At 102, in one embodiment, a sulfonic acid indicator can be introduced into a solution. The indicator can be placed into the solution at room temperature. The solution can contain an amount of zinc. In one embodiment, the zinc can cause a change in fluorescence intensity in the solution after reacting with the indicator in the solution. The change in fluorescence intensity can be proportional to the amount of zinc in the solution. The fluorescence can be excited or increased based on the interaction of the amount of zinc with the sulfonic acid indicator.
[0035] In one embodiment, the sulfonic acid indicator can be placed into a solution, an aqueous sample, a water sample, or the like. The solution can be titrated. The titration can be about equal to, higher than, or lower than a pH of 6.0. In one embodiment, the pH can be selected to minimize interference. For example, a pH about equal to or lower than a pH of 6.0 can minimize interference, and a pH higher than 6.0 can be used for a more pure water sample. In one embodiment, a surfactant can be added to the solution. The surfactant can allow for an increase in the strength of the zinc-indicator complex.
[0036] The solution can be an aqueous sample that includes a sample from a natural water body, a holding tank, a process tank, a pipe, or the like. The solution can be in a continuous flow, a static volume of liquid, or any combination thereof. In one embodiment, the solution can be introduced into a sulfonic acid indicator (e.g., a test chamber of a measurement device). In one embodiment, the measurement device can be a handheld device. The handheld device can have advantages such as lower cost, portability, field use, or the like. Alternatively, the measurement device can be a larger benchtop device. Introducing the solution into the measurement device can include placing or introducing the solution into the test chamber manually by a user or using mechanical means (e.g., gravity flow, a pump, pressure, fluid flow, or the like). For example, a pump can be used to introduce a water sample for zinc measurement into a measurement or test chamber. In one embodiment, a valve or the like can control the flow of the solution into or out of one or more chambers, if present.
[0037] The chamber, container, cell, cavity, or the like can contain an aqueous sample, at least one thiocarbamate-based indicator, and related reagents such as a surfactant, an acid, a base, and / or a buffer. The device can include one or more reagent bottles containing the necessary reagents. The reagents contained in the one or more bottles can be pumped or gravity fed. The flow of the reagents can be metered to ensure proper volume delivery to the measurement cell. The aqueous sample can be fed through a pressurized inlet, a container, or the like. The aqueous sample can be introduced into the measurement chamber by pump feeding or weight feeding. The sampling device can be in series or in parallel with the aqueous stream. The device can have a system that ensures proper mixing of the aqueous sample, the sulfonic acid indicator, and the related reagents.
[0038] Additionally or alternatively, a measurement device can be present or introduced into a volume of solution. The measurement device is then exposed to the volume of solution where it can make a measurement. The system can be a flow-through system in which the solution and / or reagents are mixed and measured automatically. As discussed in more detail herein, once the sample is in contact with the measurement system, the system can measure the zinc of the sample. In one embodiment, the measurement device can include one or more chambers in which one or more method steps can be performed.
[0039] At 103, in one embodiment, the system and method can measure the amount of zinc in the solution by measuring the change in fluorescence intensity caused by the reaction of zinc with the indicator. In one embodiment, the presence of zinc in an aqueous solution can cause an increase in the fluorescence intensity of the sulfonic acid indicator. In one embodiment, zinc can bind to the sulfonic acid indicator. For example, zinc can bind two indicator molecules (see Figure 2 ). Examples of this increase in fluorescence intensity as well as the dose response curve for the sulfonic acid indicator are shown in Figure 3 A-B and Figure 4 . As shown, the zinc concentration from 0 to 0.080 mg / L was used with N=8 and a linear curve was fit to demonstrate the approximate MDL (method detection limit) of the method. For the current method setup, the MDL was calculated to be approximately 0.008 mg / L. Thus, the change in fluorescence of the solution can be proportional to the amount of zinc within the solution. Thus, the measurement device or user can correlate the measured change in fluorescence to the amount of zinc in the solution.
[0040] Referring to Figure 3 , other examples of fluorescence intensity measurements using the sulfonic acid indicator for low range methods Figure 3 A) and high range methods Figure 3 B) are shown. In one embodiment, a low range method can be used. In one embodiment, the low range zinc (Zn(II)) detection can be in the range of approximately 0.0 to 0.25 mg / L. The low range zinc detection can use the emission scan mode of the fluorescence spectrophotometer. The low range parameters can include an excitation wavelength of 365 nm, an emission wavelength scan from 365 nm to 600 nm, and a photomultiplier tube (PMT) voltage of 500 V. In one embodiment, the high range zinc (Zn(II)) detection can be in a range higher than the low detection method, such as 0 to 3.5 mg / L or even higher concentrations. The high range zinc detection method can use the excitation scan mode of the fluorescence spectrophotometer. For example, the emission wavelength can be 524 nm and an excitation scan from 300 nm to 410 nm can be used with a PMT voltage of 335 V.
[0041] Therefore, the fluorescence intensity of a zinc-containing solution can be correlated with the concentration of zinc in the aqueous solution. In one embodiment, the amount of fluorescence can be proportional to the amount or concentration of zinc in the solution. Fluorescence profiles can be generated for various zinc concentrations, different sulfonic acid indicators, and different conditions that may affect absorption or fluorescence values (e.g., temperature, sample content, turbidity, viscosity, measuring equipment, aqueous sample chamber, etc.). The fluorescence profiles can then be used to determine the amount of zinc in the solution.
[0042] At point 104, in one embodiment, the system and method can determine whether the amount of zinc can be measured. For example, the amount of zinc can be measured using the aforementioned sulfonic acid indicator or by fluorescence. The fluorescence measurement results can be compared with expected values, historical values, etc. Zinc measurements or fluorescence measurements can be performed at user-defined periodic intervals or pre-programmed frequencies in the device. Measuring zinc via the device allows for real-time data to be obtained with very little human intervention during the measurement process. In the event of unexpected values output by the system, the system can automatically request a remeasurement of the solution or sample.
[0043] A programmed calibration curve can be input into the device for calibrating the measuring apparatus. In one embodiment, the system and method can be used to periodically test for zinc in a known amount in a sample. The system can then be recalibrated or an error report can be sent for maintenance. The system can implement a cleaning cycle in cases where errors are caused by uncleaned equipment or where the equipment requires cleaning. Cleaning of the fluorescence chamber may be required at unspecified time intervals, after a certain number of measurements, or upon request from the user or system. In one embodiment, the cleaning cycle of the fluorescence apparatus can be performed using automated or manual methods.
[0044] At point 104, in one implementation, if the zinc concentration cannot be determined, the system can continue to measure zinc and / or fluorescence signals. Alternatively, the system can output an alarm, record events, etc. If the zinc concentration can be determined, the system can provide the measurement result of the zinc concentration at point 105. The measurement result, which may be the fluorescence intensity or zinc concentration, can be the output, provided to the device in the form of display, printing, storage, audio, haptic feedback, etc. Alternatively, the output result can be transmitted to another device via wired, wireless, fiber optic, Bluetooth®, near-field communication, etc.
[0045] One implementation may use alarms to warn of measurements or concentrations outside acceptable levels. One implementation may use the system to shut off water output or divert water from sources with unacceptable zinc levels. For example, the zinc measuring device may use a relay connected to an electric valve. The system may connect to a communication network. The system may issue alarms to users or the network. This alarm may be triggered regardless of whether a zinc measurement result has been determined. Alarms may be audible, visual, data-driven, store data in a memory device, send output via a connected or wireless system, print out, etc. The system may log information such as measurement location, calibration action, geographic location, time, date, number of measurement cycles, etc. Alarms or logs may be automated, meaning the system may automatically output whether calibration is needed. The system may also have associated alarms, limits, or predetermined thresholds. For example, if the zinc concentration reaches a threshold. Alarms or logs may be: analyzed in real time, stored for later use, or any combination thereof.
[0046] Therefore, the embodiments described herein represent a technological improvement over conventional zinc measurement techniques. Using the techniques described herein, one embodiment can use a sulfonic acid indicator to measure zinc in solution. This contrasts with the use of cyanide, which has the aforementioned limitations. Such techniques provide a faster and more accurate method for measuring zinc in aqueous or liquid solutions, while using fewer hazardous or harmful chemicals or reagents in zinc measurement.
[0047] Although various other circuits, circuit systems, or components may be used in information processing devices, regarding the instrument for zinc measurement according to any of the embodiments described herein, Figure 5 An example is shown. Device circuitry 10' may include a chip-based measurement system, such as a specific computing platform (e.g., mobile computing, desktop computing, etc.). Software and one or more processors are combined in a single chip 11'. As is well known in the art, processors include an internal arithmetic logic unit (ALU), registers, cache memory, buses, I / O ports, etc. Internal buses, etc., vary depending on the vendor, but essentially all peripherals (12') can be connected to a single chip 11'. Circuitry 10' combines the processor, memory control, and I / O controller hub into a single chip 11'. Furthermore, this type of system 10' generally does not use SATA, PCI, or LPC. Common interfaces include SDIO and I2C, for example.
[0048] There are one or more power management chips 13', such as a battery management unit (BMU), which manages power supplied, for example, through 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', is used to provide BIOS-like functionality and DRAM memory.
[0049] System 10' generally 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 a wireless Internet device (e.g., an access point). Additionally, there is typically included a device 12', e.g., a transmit and receive antenna, an oscillator, a PLL, etc. System 10' includes an input / output device 17' for data input and display / rendering (e.g., a computing location easily accessible to a user that is remote from the single-beam system arrangement). System 10' generally also includes various memory devices, e.g., a flash memory 18' and a SDRAM 19'.
[0050] From the foregoing, it will be appreciated that the electronic elements of one or more systems or devices can include, among other things, at least one processing unit, memory, and a communications bus or communication means that connects various elements (including memory or one or more processors). A system or device can include or access various device-readable media. System memory can include device-readable storage media in the form of volatile and / or nonvolatile memory, such as read only memory (ROM) and / or random access memory (RAM). By way of example, and not limitation, system memory can also include an operating system, application programs, other program modules, and program data. The disclosed system can be used in one embodiment to make measurements of zinc in an aqueous sample.
[0051] Those skilled in the art will appreciate that aspects can be embodied as a system, method, or device program product. Accordingly, aspects can take the form of an entirely hardware embodiment or an embodiment including software that can all be referred to herein as a "circuit," "module" or "system." Furthermore, aspects can take the form of a device program product embodied in one or more device readable storage media having device readable program code embodied thereon.
[0052] It should be noted that the various functions described herein can 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, a storage device is not a signal and "non-transitory" includes all media except signal media.
[0053] Program code for carrying out operations can be written in any combination of one or more programming languages. The program code can execute entirely on a single device, partly on a single device, as a stand-alone software package, partly on a single device and partly on another device, or entirely on the other device. In some cases, the devices can be connected through any type of connection or network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made through other device (for example, through the Internet using an Internet Service Provider), through a wireless connection (for example, near-field communication), or through a hard-wired connection (like over a USB connection). The embodiments are not limited in this regard.
[0054] Exemplary embodiments are described herein with reference to the accompanying drawings, which show example embodiments in accordance with various exemplary embodiments. It is understood that the acts and function can be at least partly implemented by program instructions. These program instructions can be provided to a processor of a device (e.g., a hand-held measurement device) or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the device implement the functions / acts specified.
[0055] It should be noted that values provided herein are to be interpreted as including equivalent values by use of the term "about" as shown. Equivalent values will be apparent to those of ordinary skill in the art, but include at least values obtained by ordinary rounding of the last significant digit.
[0056] The present disclosure has been provided for illustration and description, but is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Various changes and modifications can be obvious to one of ordinary skill in the art, and embodiments have been chosen and described which best explain the principles and practical application, and are best suited to convey the disclosure to others skilled in the art. Embodiments have been chosen and described which best explain the principles of the disclosure and the practical application, and are best suited to convey the disclosure to others skilled in the art.
[0057] Thus, although there have been described herein example embodiments of the present disclosure, it is in no way intended that the present disclosure be limited thereto. As known to those of ordinary skill in the art, various modifications are possible in the practice within the scope of the present disclosure.
Claims
1. A method for measuring zinc in a solution, the method comprising: Prepare an indicator solution, wherein the indicator solution comprises 8-hydroxy-5-quinoline sulfonic acid; An indicator solution is introduced into a solution containing a certain amount of zinc, and the introduction causes the solution to undergo a fluorescence change in response to the reaction of the indicator solution with the zinc. A moderating agent is added to the solution, wherein the moderating agent prevents the interfering substance from binding with the indicator; and The amount of zinc in the solution is measured by measuring changes in fluorescence intensity and comparing these changes with a calibration curve generated based on the conditions of the solution, wherein the conditions affect the fluorescence measurement of the solution, and wherein the fluorescence intensity is proportional to the concentration of zinc in the solution. The method employs low-range zinc detection, wherein the low-range zinc detection utilizes the emission scanning mode of a fluorescence spectrophotometer.
2. The method of claim 1, wherein the indicator solution comprises a surfactant additive.
3. The method of claim 1, wherein the solution comprises a water sample.
4. The method of claim 1, wherein the amount of zinc includes an amount of less than 0.008 mg / L.
5. The method of claim 1, further comprising titrating the pH of the solution to a pH derived from the group consisting of: equal to pH 6, greater than pH 6, and less than pH 6.
6. The method of claim 1, wherein the zinc binds to the sulfonic acid, thereby causing the change in fluorescence intensity.
7. The method of claim 1, wherein the measurement comprises measuring zinc in the solution in the absence of cyanide compounds.
8. A measuring device for measuring zinc in a solution, the measuring device comprising: processor; and A memory storing processor-executable instructions for performing the method according to any one of claims 1-7.