Colorimetric detection of aluminum in aqueous samples

Abstract

Embodiments provide a method for measuring an aluminum concentration in an aqueous sample, the method comprising: preparing a chrome azurol S indicator solution; placing the chrome azurol S indicator solution in a sample comprising aluminum wherein the placing causes chrome azurol S to chelate aluminum in the sample, thereby forming a colored complex; and measuring the concentration of aluminum in the sample using colorimetric techniques, where the measuring comprises measuring the absorbance of the colored complex at the wavelength. Other embodiments are described and claimed.

Description

[0001] This application is a divisional application with application number 202080006954.7, application date June 11, 2021, and subject matter “Colorimetric Detection of Aluminum in Aqueous Samples”. Technical Field

[0002] The present application relates generally to water quality testing and, more particularly, to the measurement of aluminum in aqueous samples. Background Art

[0003] The measurement of aluminum is important to ensure water quality. Applications for aluminum measurement may include wastewater treatment, drinking water treatment, monitoring natural water bodies, aquaculture, beverage / food manufacturing, pharmaceuticals, boiler systems, industrial processes, petrochemical processes, chemical tanks, etc. Aluminum may be important to the viability of aquatic life and natural water bodies. Additionally, appropriate levels of aluminum may be necessary in a manufacturing or processing operation in order for the reactions or processes in the operation to occur properly. Correct measurement of aluminum may also be important to prevent aluminum from interfering with reactions in solution.

[0004] Aluminum is an abundant metal in the Earth's crust. Aluminum can leach into water supplies from rocks and / or soil. Aluminum can also be introduced during water treatment as aluminum hydroxide or aluminum sulfate. Some studies have linked the presence of aluminum to dementias, such as Alzheimer's disease. There are a variety of methods for measuring aluminum in drinking water. However, many aluminum tests require that possible interfering substances be minimized in the test. In addition, some aluminum detection tests are inaccurate for low concentrations of aluminum. Summary of the invention

[0005] One embodiment provides a method for measuring the concentration of aluminum in an aqueous sample, comprising: preparing a chrome azuro blue S indicator solution; placing the chrome azuro blue S indicator solution in a sample containing aluminum, wherein the placement causes the chrome azuro blue S to chelate aluminum in the sample to form a colored complex; and measuring the concentration of aluminum in the sample using a colorimetric technique, wherein the measurement includes measuring the absorbance of the colored complex at a wavelength.

[0006] Another embodiment provides an apparatus for measuring the concentration of aluminum in an aqueous sample, the apparatus comprising: a processor; a storage device storing instructions executable by the processor to: introduce the aqueous sample into a reaction vessel; prepare a chrome azure S indicator solution; place the chrome azure S indicator solution in a sample containing aluminum, wherein the placement causes the chrome azure S to chelate aluminum in the sample to form a colored complex; and measure the concentration of aluminum in the sample using a colorimetric technique, wherein the measurement comprises measuring the absorbance of the colored complex at a wavelength.

[0007] Another embodiment provides a measuring device for measuring the aluminum concentration in an aqueous sample, the measuring device comprising: a processor; a storage device storing instructions that can be executed by the processor to: receive a prepared chrome azuro blue S indicator solution in the measuring device; receive a sample containing aluminum in the measuring device, wherein the receiving causes the chrome azuro blue S to chelate aluminum in the sample to form a colored complex; and measure the concentration of aluminum in the sample using the measuring device and a colorimetric technique, wherein the measurement includes measuring the absorbance of the colored complex at a wavelength.

[0008] 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.

[0009] For a better understanding of the embodiments and other and further features and advantages of the embodiments, 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 DRAWINGS

[0010] Figure 1 An example of a computer circuit system is shown.

[0011] Figure 2 An exemplary flow chart for aluminum detection using a measurement system is shown.

[0012] Figure 3 An exemplary embodiment of aluminum detection using colorimetric technology is shown. DETAILED DESCRIPTION

[0013] It will be readily understood that the components of the embodiments as generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations other than the described exemplary embodiments. Therefore, the following more detailed description of the exemplary embodiments, as shown in the drawings, is not intended to limit the scope of the claimed embodiments, but merely represents exemplary embodiments.

[0014] 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 phrases "in one embodiment" or "in an embodiment", etc., appearing in various places throughout this specification are not necessarily all referring to the same embodiment.

[0015] In addition, the described features, structures or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to give a thorough understanding of the embodiments. However, those skilled in the relevant art will recognize that the various embodiments can be practiced without one or more of the specific details, or in the case of other methods, components, materials, etc. In other cases, well-known structures, materials or operations are not shown or described in detail to avoid confusion.

[0016] Colorimetric methods are commonly used to measure aluminum levels. One method includes the Hach Method 10215 test kit using the TNTplus™ 848. This method requires a recommended sample pH between 2.5 and 3.5. This method also requires a sample temperature of 20-23°C. The reagents used in this method recommend that the reagents be stored at 15-25°C. This method also requires 25 minutes to generate a measurement of aluminum, which is a significant length of time. In addition, this method only measures aluminum in the range of 0.020-0.5 parts per million (ppm). Therefore, this method does not provide measurement of lower aluminum concentrations or may provide inaccurate readings if the aluminum concentration is too low. In addition, it is recommended that samples be stored at a pH of less than 2.0 for later analysis. This method requires careful pipetting and addition of reagents in addition to a 25-minute wait time for the reaction to complete. This method uses standard colorimetric techniques, which provide a measurement of aluminum in the sample, typically in milligrams per liter. However, colorimetric assays require the use of a sample blank that is subtracted from the test results. In addition, interfering ions may cause inaccurate readings. These interfering ions include Mg 2+ , K + 、Na + NH 4 + , Cl - 、NO 3 -、SO 4 2- , Ca 2+ 、Ag + , Mn 2+ 、Cd 2+ 、Co 2+ 、Ni 2+ Sn 2+ , Pb 2+ ,PO 4 3- , Cu 2+ , Hg 2+ , Fe 2+ , Fe 3+ 、Zn 2+ 、Si 4+ Cr 3+ Cr6+ , and F - .

[0017] Therefore, current aluminum testing methods have limitations, which are overcome by methods and techniques as described in more detail herein. One limitation of current technology is that it requires a longer process than the methods described herein. In addition, traditional colorimetric methods require the preparation of a separate "blank" bottle. The additional step of preparing a blank bottle may introduce errors into the measurement based on the personal skills when preparing the blank bottle. Moreover, since traditional colorimetric techniques are sensitive to a variety of interferents, the presence of interfering ions may reduce the accuracy of the content of aluminum-containing samples. In addition, the methods described herein provide a wider range of aluminum detection than conventional techniques. Specifically, the described methods and systems provide for the measurement of aluminum concentrations at lower concentrations than traditional measurement techniques.

[0018] Thus, embodiments include preparing a chrome azuro blue S indicator solution. The preparation of the chrome azuro blue S indicator solution may include preparing chrome azuro blue S in a buffer solution. Chrome azuro blue S may also be referred to as mordant blue 29. In embodiments, the buffer may include an additive. For example, the buffer solution may include acetate, succinic acid, sodium succinate, etc. The buffer may facilitate the generation of a calibration curve, for example, a succinic acid / sodium succinate buffer may be used to generate a Figure 3 Calibration curve of . However, this is a non-limiting example, and other buffer solutions can be used. The buffer can be selected to maintain the pH value equal to, approximately equal to, less than or greater than pH 5.0. The buffer can also be selected not to interfere with analytes, such as aluminum. In addition, the buffer solution can include a surfactant. In an embodiment, a chrome azuro blue S indicator solution can be placed in an aqueous sample containing aluminum. The delivery method of a reagent such as chrome azuro blue S to an aqueous sample can be completed by pipetting, a dropper, a test strip, a powder pillow, using a solid, using a liquid solution, etc. In the case of aluminum in the sample, chrome azuro blue S can chelate the aluminum in the sample to form a colored complex. In an embodiment, a colorimetric technique can measure the concentration of aluminum from a colored complex. For example, the measurement can be a measurement of the absorbance of the colored complex at a wavelength. The measurement can include obtaining a ratio of absorbances collected at multiple wavelengths. The measurements may be performed using different measurement devices, such as a portable parallel analyzer (PPA, such as the SL1000 available from Hach Company, Loveland, CO), test strips, colorimetric analyzers, spectrophotometers, pocket colorimeters, on-line process instruments, and the like.

[0019] The illustrated exemplary embodiments will be best understood by reference to the accompanying drawings.The following description is intended by way of example only and merely illustrates certain exemplary embodiments.

[0020] Although various other circuits, circuit systems, or components may be used in the information processing device with respect to the instrument for aluminum measurement according to any of the various embodiments described herein, Figure 1 An example is shown in . For example, Figure 1 The device circuit system described in the embodiment can be used to transmit the measurement results to another device, or can be used as a device for receiving the measurement results. The device circuit system 100 can include a measurement system on a chip design scheme of a specific computing platform (e.g., mobile computing, desktop computing, etc.). The software and the processor are combined in a single chip 101. The processor includes an internal arithmetic unit, registers, cache memory, bus, I / O ports, etc. as well known in the art. Although the internal bus, etc. depends on different suppliers, basically all peripheral devices (102) can be attached to a single chip 101. The circuit system 100 combines the processor, memory control and I / O controller hub into a single chip 101. Moreover, this type of system 100 typically does not use SATA or PCI or LPC. For example, common interfaces include SDIO and I2C.

[0021] There is a power management chip 103, such as a battery management unit BMU, which manages power supplied, for example, via a rechargeable battery 104, which can be charged by connection to a power source (not shown). In at least one design, a single chip (such as 101) is used to supply BIOS-like functions and DRAM memory.

[0022] The system 100 typically includes one or more of a WWAN transceiver 105 and a WLAN transceiver 106 for connecting to various networks, such as telecommunication networks and wireless Internet devices, such as access points. In addition, it generally includes devices 102, such as transmit and receive antennas, oscillators, RF amplifiers, PLLs, etc. The system 100 includes input / output devices 107 for data input and display / rendering (e.g., located away from the computing location of the single beam system for easy access by the user). The system 100 also typically includes various storage devices, such as flash memory 108 and SDRAM 109.

[0023] It can be understood from the foregoing that 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 connected to various components of the memory including the processing unit. The system or device may include or have access to various device-readable media. The system memory may include volatile and / or non-volatile memory such as device-readable storage media in the form of read-only memory (ROM) and / or random access memory (RAM). As an 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 an embodiment to perform aluminum measurements of aqueous samples.

[0024] Reference now Figure 2 , embodiments provide measurements of aluminum concentrations in aqueous environments. In embodiments, a chrome azuro blue S indicator solution may be prepared. The chrome azuro blue S indicator solution may be placed in a sample containing aluminum, such as an aqueous sample. Chrome azuro blue S may chelate aluminum in the sample. This chelation process may result in the formation of a colored complex. The resulting colored complex may be used to identify the concentration of aluminum in the sample. For example, using colorimetric techniques, parameters of the colored complex may be measured. For example, colorimetric techniques may be used to measure the absorbance of the colored complex at one or more wavelengths. The absorbance may be proportional to the absorbance at a wavelength, a ratio of absorbances measured at multiple wavelengths, and the like.

[0025] At 201, in an embodiment, a chrome azuro blue S indicator solution may be prepared. Chrome azuro blue S may be from a commercial source or may be synthesized in-house. Unlike conventional techniques, the preparation of the indicator solution may be performed at a pH of 5.0, around, below, or above a pH of 5.0. Compared to conventional techniques, the preparation of the indicator solution at a pH of 5.0, around, below, or above a pH of 5.0 may allow a wider range of aluminum to be measured. The preparation of the chrome azuro blue S indicator solution may include preparing the chrome azuro blue S in a buffer solution. The buffer components of the buffer solution may be selected based on interactions with aluminum. In other words, the components may be selected to reduce interactions with aluminum. In addition, the buffer components may be selected to chelate with interfering metals, etc., that may be expected in an aqueous sample. In one embodiment, the buffer may include acetate or succinic acid. The buffer and / or the indicator solution may additionally or alternatively include additives. The additive may include a surfactant or an alcohol. The surfactant may produce micelles in the solution. As a result, the maximum wavelength may shift. The micelles and subsequent wavelength shift can be selected to take advantage of devices or conditions that may require a shift in the absorbance wavelength. For example, if the measurement device is tuned for a specific absorbance wavelength measurement, a surfactant can be added to produce a reaction that will allow the absorbance measurement to be measured by the device.

[0026] At 202, a chrome azuro blue S indicator solution can be placed in a sample, such as an aqueous sample. As an example, a user may want to measure the aluminum concentration in a natural water source (e.g., pond, lake, stream, etc.), a residential water source (e.g., swimming pool, residential water supply, etc.), a commercial or municipal water source (e.g., a water treatment facility, a water storage tank, a facility water supply, a laboratory sample, etc.), etc. Therefore, a chrome azuro blue S indicator solution can be placed or otherwise introduced into an aqueous sample. Different techniques can be used to introduce an indicator solution into an aqueous sample. For example, a sample can be placed in a bottle, a measuring device, a container, etc., and then an indicator solution can be introduced into the sample, such as by using a dropper, a pipette, a powder pillow, a test strip, etc. Alternatively, an indicator solution can be placed in a bottle, a measuring device, a container, etc., and then the sample is introduced into the indicator solution.

[0027] The sample may contain aluminum. Aluminum may be in the form of a pure substance or a compound. Additionally or alternatively, aluminum may be in the form of a liquid or fine suspension in an aqueous sample. In an embodiment, an aluminum sample and / or an indicator solution may be added to a reaction vessel or other chamber of a measuring device. The introduction of an aluminum sample and / or an indicator solution may be automatic or manual. For example, the sample for testing may be pumped, aliquoted, pipetted or introduced into a container or device in any manner. The aluminum for testing may come from a variety of sources, for example, aluminum may come from municipal water, drinking water, surface water, wastewater, industrial sewage, natural waterways, manufacturing processes, swimming pools, etc. The method and system may have more than one reaction vessel. For example, an aluminum sample may be introduced into a first container, and the subsequent steps of the embodiment may occur in another one or more containers. For example, a sample may be introduced into a first container or chamber, an indicator solution may be introduced into a second container or chamber, and then the sample and the indicator solution may be mixed into a third container or chamber.

[0028] The chamber, container, pool, etc. can contain aqueous sample, chrome azuro blue S indicator solution, buffer and related reagents. The equipment can include one or more reagent bottles, and one or more reagent bottles contain necessary reagents, such as but not limited to: chrome azuro blue S indicator solution, buffer or any reagent that may not be premixed before the measurement process. The reagent contained in one or more bottles can be pump-fed or gravity-fed. The flow of reagent can be metered to ensure that the correct amount is delivered to the measurement pool. The aqueous sample can be fed by pressure inlet, container, etc. The aqueous sample can be introduced into the measurement chamber by pump-fed or gravity-fed. The sampling device can be connected in series or in parallel with the aqueous stream. The equipment can have a system to ensure the correct mixing of aqueous sample, chrome azuro blue S indicator solution and related reagents.

[0029] Aqueous samples can include samples from natural water bodies, water storage tanks, treatment water tanks, pipelines, etc. The sample containing aluminum can be a continuous flow, a static amount of liquid, or any combination thereof. In one embodiment, the sample containing aluminum can be introduced into a container, such as a test chamber of a measuring device. Introducing the sample containing aluminum into the measuring device can include placing or introducing the sample containing aluminum into the test chamber manually by the user or using mechanical means such as gravity flow, pumps, pressure, fluid flow, etc. For example, a water sample for aluminum testing can be introduced into a measuring chamber or a test chamber using a pump. In one embodiment, valves, etc. can control the inflow and outflow of aqueous solutions into or out of one or more chambers (if present). In an embodiment, pumps, valves, and pipelines can control and guide the flow of reagents such as indicator solutions. In an embodiment, these systems can be automated or controlled by a processor.

[0030] Additionally or alternatively, the measuring device may be present in or introduced into a certain amount of a sample containing aluminum. The measuring device is then exposed to a certain amount of an aqueous sample where the measurement can be performed. For example, a handheld measuring device may include a test strip, a test chip (such as Chemkeys available from Hach Company, Loveland, Colorado), etc., which allows the device or a portion of the device to be immersed in an aqueous sample, and then a portion of the aqueous sample is pulled into the measuring device. As another example, the measuring device may be positioned in or near a water source or sample source, and samples may be periodically pulled for measurement. The system may be a flow-through system in which samples and / or reagents containing aluminum are automatically mixed and measured. Once the sample contacts the measuring system, the system may measure the aluminum in the sample using a colorimetric technique. In an embodiment, the measuring device may include one or more chambers in which one or more method steps may be performed.

[0031] At 203, in an embodiment, the system may determine whether it is possible to determine or measure the concentration of aluminum in the sample. To make this determination, the system may attempt to measure the concentration of aluminum in the sample using, for example, one or more colorimetric techniques. In an embodiment, the indicator solution may include a colorimetric indicator and be sensitive to aluminum. Therefore, once the indicator solution or the components in the indicator solution are introduced into a sample containing aluminum, they react with the aluminum in the sample, thereby producing a colorimetric change in the sample. Specifically, when the indicator solution is introduced into an aqueous sample, an indicator such as chrome azuro blue S can chelate the aluminum in the aqueous sample. This chelation causes a colorimetric change in the indicator solution. In other words, the color of the colored complex produced by the chelation is different from the color of the indicator solution or aqueous sample alone. In other words, chelation causes the absorbance wavelength of the indicator solution and the aqueous sample to change.

[0032] The colorimetric indicator can be water soluble. The colorimetric indicator can be chrome azuro blue S. The indicator can give a visual indication of the aluminum concentration, which can be determined by an absorbance measurement performed using a laboratory apparatus or other measuring device. The color or absorbance change produced by the interaction of the indicator with the aluminum in the sample can be determined photometrically, for example, using a spectrophotometer. For example, the measuring device can measure the absorption wavelength of the colored complex. The absorption wavelength can be proportional to the concentration of aluminum in the sample. Therefore, by identifying the absorption wavelength, the system can measure the concentration of aluminum in the sample. In one embodiment, two or more absorption wavelengths can be measured. The aluminum concentration can then be proportional to the ratio of the multiple absorption wavelengths. The absorbance intensity of free chrome azuro blue S can also be monitored and used as an internal reference.

[0033] The concentration of aluminum can be determined in a variety of ways. For example, a comparison of known concentrations of aluminum to an indicator or absorbance wavelength can be used to create a calibration curve of known aluminum concentrations. As another example, the absorbance of a sample containing aluminum can be determined using a set of aluminum samples of known concentrations to generate a calibration curve. The absorbance wavelength of the resulting colored complex can also be compared to a "blank" to determine the concentration of aluminum in the sample.

[0034] refer to Figure 3 , shows an exemplary embodiment of determining the aluminum concentration in a sample using colorimetric techniques. The described system or method can determine whether a colorimetric change has occurred in a sample. Specifically, a colorimetric change may occur in a solution due to the presence of aluminum concentration in the solution. In an embodiment, a ratio of absorbances can be obtained. For example, a spectrophotometer can obtain absorbances at two wavelengths. In Figure 3 In the example shown in Figure 1, the two wavelengths are 548 nm and 427 nm. The ratio of these two wavelengths may be proportional to the concentration of aluminum in the sample. Therefore, the system can determine the aluminum concentration based on the two wavelengths.

[0035] For example, the method described herein can chelate aluminum in the presence of a chrome azuro blue S indicator solution. For example, the chelation of aluminum can form a colored complex and may cause a decrease in the absorbance intensity at 427 nm and an increase in the absorbance intensity at 548 nm. In this way, the method can be used as its own control. Although a blank can be prepared, a blank may not be required. The blank can be used for regular calibration or testing. In an embodiment, a ratio absorbance can be drawn on the concentration of aluminum. In an embodiment, the reaction occurs quickly, so the measurement of aluminum concentration is much faster than conventional techniques. The detectable range of aluminum concentration can depend on the slope of the calibration curve. The calibration curve can be optimized using the path length and / or instrument performance of the sample cell. The change in absorbance may be proportional to the aluminum concentration in the sample. Colorimetric measurements can be performed using standard laboratory equipment (such as a spectrophotometer).

[0036] The determination may also be made based on predicted absorbance under known conditions. The prediction may be based on variables such as temperature, pH, turbidity, path length, instrument use, etc. For example, the system may be programmed with a calibration curve. Deviations from the predicted curve may make the results less reliable and cause the system to abort the measurement or send an alarm. As another example, the system may receive information indicating that multiple measurement cycles for measuring aluminum concentration are outside acceptable limits. For example, such measurements may indicate that a step in the process may not be optimal. Such steps may include aluminum chelation, indicator concentration, pH, temperature, etc. At 205, in an embodiment, if the concentration of aluminum cannot be determined, the system may continue to measure aluminum, obtain another sample, attempt to chelate aluminum, etc. Additionally or alternatively, the system may output an alarm, record an event, etc.

[0037] If the concentration of aluminum can be determined at 203, the system can provide a measurement of the aluminum concentration at 204. The change in absorption can be measured using a spectrophotometer. Spectrophotometry is the measurement of the reflectance or transmission properties of a sample measured at a given wavelength or set of wavelengths. Spectrophotometry can be a quantitative measurement of how much light is absorbed by a colored complex produced by the chelation of a material, such as an indicator solution, with aluminum. For example, while the color of chrome azure S in solution may be yellow / orange (427 nm), the maximum absorbance of the aluminum-chrome azure S complex may be about 548 nm. Changes in absorption can also be measured using other colorimetric measurement devices.

[0038] Alternatively or additionally, aluminum concentration measurements can be made at periodic intervals set by the user or at a pre-programmed frequency in the device. Measurement of aluminum by the device allows real-time data and requires little human involvement in the measurement process. Cleaning of the colorimetric chamber may be required at unspecified intervals. Programmed calibration curves can be input into the device.

[0039] The aluminum measurement may be an output on the device in the form of display, printing, storage, audio, tactile feedback, etc. Alternatively or additionally, the output may be sent to another device via wired, wireless, fiber optic, Bluetooth®, near field communication, etc. Embodiments may use an alarm to warn that the aluminum measurement or concentration is outside of an acceptable level. Embodiments may use a system to shut off water output or divert water from a source with an unacceptable level of aluminum. For example, an aluminum measurement device may use a relay coupled to an electrically actuated valve, etc.

[0040] As will be appreciated by those skilled in the art, various aspects may be embodied as systems, methods, or device program products. Thus, various aspects may take the form of a complete hardware embodiment or an embodiment including software, which may all be generally referred to herein as a "circuit," "module," or "system." Additionally, various aspects may take the form of a device program product embodied in one or more device-readable media having device-readable program code embodied therewith.

[0041] 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, wherein 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.

[0042] Program code for performing operations may be written in any combination of one or more programming languages. The program code may be executed entirely on a single device, partially on a single device as a standalone software package, partially on a single device and partially on another device, or entirely on another device. In some cases, the devices may be connected via any type of connection or any type of network including a local area network (LAN) or a wide area network (WAN), or the connection may be made via other devices (e.g., via the Internet using an Internet service provider), via a wireless connection such as near field communication, or via a hardwired connection (such as via a USB connection).

[0043] Exemplary embodiments are described herein with reference to the accompanying drawings, which illustrate example methods, devices, and products according to various exemplary embodiments. It will be understood that the actions and functions may be implemented at least in part by program instructions. These program instructions may be provided to a processor of a device, such as a processor. Figure 1 The handheld measuring device shown, or other programmable data processing device, to produce a machine, causes instructions executed via the processor of the device to perform specified functions / actions.

[0044] Note that the values ​​provided herein should be interpreted to include equivalent values ​​indicated by the use of the term “about.” Equivalent values ​​will be apparent to one of ordinary skill in the art, but at least include values ​​obtained by ordinary rounding of the last significant figure.

[0045] Although the present disclosure has been presented for the purpose of illustration and description, it is not intended to be exhaustive or limiting. Many modifications and variations will be apparent to those of ordinary skill in the art. The exemplary embodiments are selected and described in order to explain the principles and practical applications and to enable others of ordinary skill in the art to understand the disclosure of various embodiments with various modifications that are suitable for the intended specific use.

[0046] Thus, although exemplary embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the description is not limiting and that various other changes and modifications may be made therein by those skilled in the art without departing from the scope or spirit of the invention.

Claims

1. A method for measuring the concentration of aluminum in an aqueous sample, include: Prepare chrome azurol S indicator solution; placing the chrome azuro blue S indicator solution in a sample containing aluminum, wherein the placing causes the chrome azuro blue S to chelate aluminum in the sample to form a colored complex, wherein the sample comprises the same volume of liquid; and The concentration of aluminum in the sample is measured using a colorimetric technique, wherein the measurement includes measuring the absorbance of the colored complex at a wavelength and measuring the absorbance of the colored complex at a wavelength in the presence of aluminum, wherein the concentration of aluminum is based on the ratio of the absorbance of the colored complex at a wavelength and the absorbance of the colored complex at a wavelength in the presence of aluminum.

2. The method according to claim 1, in, The measuring includes: measuring absorbance intensities at two different wavelengths; and creating a ratio of the two absorbance intensities to generate a ratio absorbance intensity.

3. The method according to claim 2, in, The ratiometric absorbance intensity is proportional to the concentration of aluminum in the sample, and wherein the measuring includes determining the concentration of aluminum based on a calibration curve.

4. The method according to claim 1, in, The preparation includes dissolving the chrome azuro blue S indicator in a buffer solution.

5. The method according to claim 4, in, The buffer solution includes an additive selected from the group consisting of acetate and succinate.

6. The method according to claim 4, in, The dissolving includes dissolving the chromeazurol S indicator in a buffer solution at a predetermined pH value to maximize the intensity of a desired wavelength.

7. The method according to claim 1, in, The measurement includes: monitoring the absorbance intensity of free chrome azurol S in the indicator solution.

8. The method according to claim 1, further comprising: include: Additives are added to shift the absorption wavelength.

9. The method according to claim 1, in, The preparation includes preparing the chrome azurol S in a measuring device selected from the group consisting of a powder pillow, a test strip, and a liquid solution.

10. The method according to claim 1, in, The measuring includes comparing the wavelength of the absorbance with the absorbance wavelength of a blank.

11. An apparatus for measuring the concentration of aluminum in an aqueous sample, include: processor; A storage device storing instructions executable by a processor to: Prepare chrome azurol S indicator solution; placing the chrome azuro blue S indicator solution in a sample containing aluminum, wherein the placing causes the chrome azuro blue S to chelate aluminum in the sample to form a colored complex, wherein the sample comprises the same volume of liquid; and The concentration of aluminum in the sample is measured using a colorimetric technique, wherein the measurement includes measuring the absorbance of the colored complex at a wavelength and measuring the absorbance of the colored complex at a wavelength in the presence of aluminum, wherein the concentration of aluminum is based on the ratio of the absorbance of the colored complex at a wavelength and the absorbance of the colored complex at a wavelength in the presence of aluminum.

12. The device according to claim 11, in, The measuring includes: measuring absorbance intensities at two different wavelengths; and creating a ratio of the two absorbance intensities to generate a ratio absorbance intensity.

13. The device according to claim 12, in, The ratiometric absorbance intensity is proportional to the concentration of aluminum in the sample, and wherein the measuring includes determining the concentration of aluminum based on a calibration curve.

14. The device according to claim 11, in, The preparation includes dissolving the chrome azuro blue S indicator in a buffer solution.

15. The device according to claim 14, in, The buffer solution includes an additive selected from the group consisting of acetate and succinate.

16. The device according to claim 14, in, The dissolving includes dissolving the chromeazurol S indicator in a buffer solution at a predetermined pH value to maximize the intensity of a desired wavelength.

17. The device according to claim 11, in, The measurement includes: monitoring the absorbance intensity of free chrome azurol S in the indicator solution.

18. The device according to claim 11, further comprising: include: Additives are added to shift the absorption wavelength.

19. The method according to claim 11, in, The preparing includes preparing the chromeazurol S in a measuring device selected from the group consisting of a powder pillow, a test strip, and a liquid solution.

20. A measuring device for measuring the aluminum concentration in an aqueous sample, include: processor; A storage device storing instructions executable by a processor to: receiving the prepared chrome azuro blue S indicator solution in the measuring device; receiving a sample containing aluminum in the measuring device, wherein the receiving causes chrome azuroin S to chelate aluminum in the sample to form a colored complex, wherein the sample comprises a same volume of liquid; and The concentration of aluminum in the sample is measured using the measuring device and the colorimetric technique, wherein the measurement includes measuring the absorbance of the colored complex at a wavelength and measuring the absorbance of the colored complex at a wavelength in the presence of aluminum, wherein the concentration of aluminum is based on the ratio of the absorbance of the colored complex at a wavelength and the absorbance of the colored complex at a wavelength in the presence of aluminum.

Images