Method for rapidly detecting concentration of chromate ions or mercury ions in aqueous solution based on intelligent terminal

Abstract

The invention relates to a method for rapidly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal, and belongs to the technical field of fluorescent probe detection application. The method comprises the following steps: soaking Eu-MOF detection test paper into a chromate ion solution or a mercury ion solution with a standard gradient concentration, and shooting a fluorescence image of the soaked Eu-MOF detection test paper through an intelligent terminal under the irradiation of an ultraviolet light source; extracting RGB values of fluorescence images corresponding to chromate ion solutions or mercury ion solutions with different concentrations, calculating a B / R value, and establishing a B / R value-chromate ion concentration standard curve or a B / R value-mercury ion concentration standard curve; the Eu-MOF detection test paper is soaked in a solution with the concentration of chromate ions or mercury ions to be detected, a fluorescence image of the Eu-MOF detection test paper is shot through an intelligent terminal to obtain an actually-measured B / R value, and the concentration of the chromate ions or the mercury ions is detected according to the actually-measured B / R value, a B / R value-chromate ion concentration standard curve or the actually-measured B / R value and a B / R value-mercury ion concentration standard curve. And comparing to obtain the concentration of chromate ions or mercury ions in the solution to be detected.

Description

Technical Field

[0001] The invention relates to a method for quickly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal, and belongs to the technical field of fluorescent probe detection applications. Background Art

[0002] With the development of industry, water pollution and environmental problems are becoming increasingly serious. A large amount of wastewater with high concentrations of heavy metal ions, anions and various organic pollutants is discharged, which seriously endangers human health and the ecological environment. Among them, chromate ions or mercury ions are widely used in industrial production and are also highly toxic environmental pollutants. At the same time, chromate ions or mercury ions are bioaccumulative and difficult to degrade in the natural environment. Excessive intake of chromate ions or mercury ions can lead to a series of serious diseases and even cancer. Even a small amount of intake will gradually accumulate in the human body to form a variety of chronic diseases. Therefore, it is of great significance to develop a simple and quick detection method to detect the concentration of chromate ions or mercury ions in aqueous solutions.

[0003] At present, atomic absorption spectroscopy, atomic emission spectroscopy, atomic fluorescence spectroscopy, inductively coupled plasma mass spectrometry, colorimetry, ultraviolet-visible spectrophotometry and other methods are widely used for the detection of chromate ions or mercury ions. However, these methods are time-consuming, unable to be detected on site, complicated to operate, low in precision and expensive equipment, which in turn limits the scope of their application. Summary of the invention

[0004] In view of the problems that the detection of chromate ions or mercury ions in solutions in the prior art is time-consuming, cannot be detected on site, is complicated to operate, has low precision and expensive equipment, the present invention proposes a method for quickly detecting the concentration of chromate ions or mercury ions in aqueous solution based on an intelligent terminal. Lanthanide luminescent metal organic framework (Eu-MOF) has multiple adjustable luminescence centers and exhibits excellent luminescence properties, such as a larger Stokes shift, a longer fluorescence lifetime and a narrower emission band. Eu-MOF is prepared into Eu-MOF detection test paper, and the Eu-MOF is combined with an intelligent terminal to realize simple, rapid and on-site real-time detection of the concentration of chromate ions or mercury ions.

[0005] The technical scheme of the present invention comprises the following steps: immersing a Eu-MOF test paper into a chromate ion solution or a mercury ion solution with a standard gradient concentration, and photographing a fluorescent image of the Eu-MOF test paper after immersion through an intelligent terminal under irradiation with an ultraviolet light source; extracting RGB values ​​of the fluorescent images corresponding to chromate ion solutions or mercury ion solutions with different concentrations, and calculating a B / R value at the same time, and establishing a B / R value-chromate ion concentration standard curve or a B / R value-mercury ion concentration standard curve; immersing the Eu-MOF test paper into a solution with a chromate ion or mercury ion concentration to be measured, and photographing a fluorescent image of the Eu-MOF test paper through an intelligent terminal to obtain a measured B / R value, and comparing and obtaining the chromate ion or mercury ion concentration in the solution to be measured according to the measured B / R value, the B / R value-chromate ion concentration standard curve, or the measured B / R value and the B / R value-mercury ion concentration standard curve.

[0006] A method for quickly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal, the specific steps are as follows:

[0007] (1) preparing a series of chromate ion solutions or mercury ion solutions with standard gradient concentrations, respectively immersing the Eu-MOF test paper in the chromate ion solutions or mercury ion solutions with standard gradient concentrations, and photographing the fluorescence image of the Eu-MOF test paper after immersion through an intelligent terminal under ultraviolet light;

[0008] (2) extracting the RGB values ​​of the fluorescence images corresponding to the chromate ion solutions of different concentrations, calculating the B / R values, and establishing a B / R value-chromate ion concentration standard curve according to the B / R values ​​and the corresponding chromate ion concentrations; or extracting the RGB values ​​of the fluorescence images corresponding to the mercury ion solutions of different concentrations, calculating the B / R values, and establishing a B / R value-mercury ion concentration standard curve according to the B / R values ​​and the corresponding mercury ion concentrations;

[0009] (3) The Eu-MOF test paper is immersed in a solution of the chromate ion concentration to be tested, and under the irradiation of an ultraviolet light source, a fluorescent image of the Eu-MOF test paper after immersion is captured by an intelligent terminal, and the measured RGB value of the fluorescent image is extracted, and the measured B / R value is calculated at the same time. The chromate ion concentration in the solution to be tested is obtained by comparison based on the measured B / R value and the B / R value-chromate ion concentration standard curve; or, the Eu-MOF test paper is immersed in a solution of the mercury ion concentration to be tested, and under the irradiation of an ultraviolet light source, a fluorescent image of the Eu-MOF test paper after immersion is captured by an intelligent terminal, and the measured RGB value of the fluorescent image is extracted, and the measured B / R value is calculated at the same time. The mercury ion concentration in the solution to be tested is obtained by comparison based on the measured B / R value and the B / R value-mercury ion concentration standard curve.

[0010] Preferably, the Eu-MOF test paper has a fluorescence sensing function for chromate ions with a sensitivity of 1.73x10 5 M -1 The detection limit is 3.78nM; the Eu-MOF test paper has a fluorescence sensing function for mercury ions, with a sensitivity of 4.68x10 5 M -1 The detection limit was 1.39nM.

[0011] Preferably, the preparation method of the Eu-MOF detection test paper in step (1) comprises the following specific steps:

[0012] 1) Eu(NO3)3·6H2O, [2,2'-biquinoline]-4,4'-dicarboxylic acid and 1,10-phenanthroline are mixed and dissolved in a solvent to obtain a mixed solution, the mixed solution is added into a sealed high-pressure reactor, hydrothermally reacted at a temperature of 120-140°C for 70-80h, cooled to room temperature, solid-liquid separation, and the solid is washed and dried to obtain the product Eu-MOF;

[0013] 2) grinding the product Eu-MOF to obtain Eu-MOF powder, and ultrasonically dispersing the Eu-MOF powder into anhydrous ethanol to obtain a Eu-MOF suspension;

[0014] 3) Soak the fiber filter paper in the Eu-MOF suspension, ultrasonically treat for 5 to 10 minutes, take out and dry, repeat the soaking-drying process to obtain the Eu-MOF detection test paper.

[0015] Preferably, the solvent in step 1) is N,N-dimethylformamide; the molar ratio of Eu(NO3)3·6H2O, [2,2'-biquinoline]-4,4'-dicarboxylic acid and 1,10-phenanthroline is 1.8-2.1:1-3:1, preferably, the molar ratio of Eu(NO3)3·6H2O, [2,2'-biquinoline]-4,4'-dicarboxylic acid and 1,10-phenanthroline is 2:2:1.

[0016] More preferably, in the mixed solution of step 1), the concentration of Eu(NO3)3 is 10-20 mg / mL, the concentration of [2,2'-biquinoline]-4,4'-dicarboxylic acid is 5-30 mg / mL, and the concentration of 1,10-phenanthroline is 2-4 mg / mL.

[0017] Preferably, in step 2), the particle size of the Eu-MOF powder is 5 to 30 μm, and the concentration of the Eu-MOF suspension is 0.1 to 5 mg / mL.

[0018] Preferably, the soaking time in step 3) is 5 to 10 minutes.

[0019] Preferably, the concentration gradient of the chromate ion solution in step (1) is 5 μmol / L, and the concentration range of a series of standard gradient concentrations of chromate ion solutions is 0 to 800 μmol / L; the concentration gradient of the mercury ion solution is 5 μmol / L, and the concentration range of a series of standard gradient concentrations of mercury ion solutions is 0 to 50 μmol / L.

[0020] Preferably, the immersion time in step (1) is the same as the immersion time in step (3), and the wavelength of the ultraviolet light source is 360-375 nm; preferably, the wavelength of the ultraviolet light source is 370 nm, and the wavelength of the Eu-MOF emission spectrum is 580 nm, 592 nm, 615 nm, 650 nm, and 698 nm. After adding chromate ions or mercury ions, the fluorescence emission intensity at 615 nm is weakened, showing a fluorescence signal of fluorescence off. Based on this principle, a sensing function of the fluorescence emission intensity at 615 nm and the concentration of chromate ions or mercury ions can be constructed.

[0021] More preferably, the soaking time is 5 to 20 minutes.

[0022] Preferably, the intelligent terminal can take pictures, save, preprocess the image and extract the RGB mean value of the fluorescent image of the Eu-MOF test paper after immersion.

[0023] The beneficial effects of the present invention are:

[0024] (1) The present invention prepares Eu-MOF detection test paper from Eu-MOF, and combines it with an intelligent terminal to achieve simple, rapid, accurate, and on-site real-time detection of chromate ion or mercury ion concentration;

[0025] (2) Compared with existing detection methods, the method of the present invention has the advantages of fast detection speed, simple operation and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 : are the excitation spectrum and emission spectrum of Eu-MOF in Example;

[0027] Figure 2 The fluorescence response of Eu-MOF to different concentrations of chromate ions in Example 1;

[0028] Figure 3 The fluorescence response of Eu-MOF to different concentrations of mercury ions in Example 5;

[0029] Figure 4 The test paper fluorescence images of different concentrations of chromate ions in Example 1;

[0030] Figure 5 The test paper fluorescence images of different concentrations of mercury ions in Example 5;

[0031] Figure 6 is the B / R value-chromate ion concentration standard curve in Example 1;

[0032] Figure 7 is the B / R value-mercury ion concentration standard curve in Example 5;

[0033] Figure 8 This is the fluorescence image measured in Example 1;

[0034] Fig. 9 This is the measured fluorescence image of Example 2;

[0035] Fig.10 This is the measured fluorescence image of Example 5;

[0036] Fig.11 This is the measured fluorescence image of Example 6. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with specific implementation modes, but the protection scope of the present invention is not limited to the described contents.

[0038] The preparation method of the Eu-MOF test paper in the embodiment of the present invention comprises the following specific steps:

[0039] 1) Eu(NO3)3·6H2O, [2,2'-biquinoline]-4,4'-dicarboxylic acid and 1,10-phenanthroline are mixed and dissolved in a solvent (N,N-dimethylformamide) to obtain a mixed solution, the mixed solution is added into a sealed high-pressure reactor, hydrothermally reacted at a temperature of 120°C for 72 hours, cooled to room temperature, solid-liquid separation, and the solid is washed and dried to obtain the product Eu-MOF; the molar ratio of Eu(NO3)3·6H2O, [2,2'-biquinoline]-4,4'-dicarboxylic acid and 1,10-phenanthroline is 1.936:2:1, the concentration of Eu(NO3)3 in the mixed solution is 14 mg / mL, the concentration of [2,2'-biquinoline]-4,4'-dicarboxylic acid is 12 mg / mL, and the concentration of 1,10-phenanthroline is 3 mg / mL;

[0040] The emission and excitation spectra of Eu-MOF were tested by fluorescence spectrophotometer. The test results are as follows: Figure 1 As shown, from Figure 1 It can be seen that the optimal excitation wavelength of Eu-MOF is 370nm, and the emission wavelengths are 580nm, 592nm, 615nm, 650nm, and 698nm. The five spectral lines are Eu 3+ The characteristic peaks of Eu-MOF indicate that the Eu-MOF can emit fluorescence through the “antenna effect”;

[0041] 2) The product Eu-MOF is ground to obtain Eu-MOF powder with a particle size of 5 to 30 μm, and the Eu-MOF powder is ultrasonically dispersed in anhydrous ethanol to obtain a Eu-MOF suspension with a concentration of 1.5 mg / mL;

[0042] 3) Soak the fiber filter paper in the Eu-MOF suspension, ultrasonically treat for 5 minutes, take out and dry, repeat the soaking-drying process to obtain the Eu-MOF detection test paper.

[0043] Example 1: A method for quickly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal, the specific steps are as follows:

[0044] (1) A series of standard gradient concentration chromate ion solutions were prepared (the concentrations were 0 μM, 5 μM, 10 μM, 20 μM, 30 μM, 40 μM, 50 μM, 100 μM, 200 μM, 400 μM, 600 μM, and 800 μM, respectively). Eu-MOF test strips were immersed in the standard gradient concentration chromate ion solutions (immersion for 15 min), and fluorescent images of the Eu-MOF test strips after immersion were captured by an intelligent terminal under ultraviolet light (wavelength of 370 nm) (see Figure 2). Figure 4 );

[0045] The fluorescence response of Eu-MOF to different concentrations of chromate ions is shown in Figure 2 ,from Figure 2 It can be seen that the fluorescence intensity of the Eu-MOF suspension gradually decreases with the increase of chromate ion concentration, indicating that Eu-MOF has the ability to detect chromate ions;

[0046] (2) Extract the RGB values ​​of the fluorescence images corresponding to the chromate ion solutions of different concentrations, and calculate the B / R value. According to the B / R value and the corresponding chromate ion concentration, establish the B / R value-chromate ion concentration standard curve (see Figure 6 ),from Figure 6 It can be seen that there is a correlation between the B / R value and the chromate ion concentration, especially a linear relationship with the chromate ion concentration in the range of 0-50μM; based on this standard curve, the chromate ion concentration can be directly obtained by measuring the B / R value;

[0047] (3) The Eu-MOF test paper was immersed in a solution with a chromate ion concentration (20 μM) to be tested (15 min). Under ultraviolet light, the measured fluorescence image of the Eu-MOF test paper after immersion was captured by a smart terminal (see Figure 8), extract the measured RGB values ​​(222.2, 21.4, 61.9) of the measured fluorescence image, and calculate the measured B / R value (0.279). According to the measured B / R value and the B / R value-chromate ion concentration standard curve, the chromate ion concentration in the test solution (20.4 μM) is obtained by comparison;

[0048] In this embodiment, the detected concentration value of chromate ions in the solution to be tested is 20.4 μM, and the actual concentration value is 20 μM, with an error of 2%.

[0049] Example 2: The difference between this example and Example 1 is that the solution to be tested contains chromate ions (concentration of 200 μM), iodide ions (concentration of 800 μM), chloride ions (concentration of 800 μM), and fluoride ions (concentration of 800 μM);

[0050] The same method as in Example 1 was used to detect the test solution, and the measured fluorescence image of the Eu-MOF test paper after immersion was captured by the smart terminal (see Fig. 9 ), extract the measured RGB values ​​(213.3, 35.7, 108.2) of the measured fluorescence image, and calculate the measured B / R value (0.507). According to the measured B / R value and the B / R value-chromate ion concentration standard curve, the chromate ion concentration in the test solution (190 μM) is obtained by comparison;

[0051] In this embodiment, the detected concentration value of chromate ions in the solution to be tested is 190 μM, and the actual concentration value is 200 μM, with an error of 5%.

[0052] Example 3: The difference between this example and Example 1 is that the concentration of chromate ions in the solution to be tested is 30 μM;

[0053] The test solution was tested by the same method as in Example 1, and the measured fluorescence image of the Eu-MOF test paper after immersion was captured by the intelligent terminal, and the measured RGB values ​​(217.1, 24.3, 71.2) of the measured fluorescence image were extracted, and the measured B / R value (0.328) was calculated at the same time. According to the measured B / R value and the B / R value-chromate ion concentration standard curve, the chromate ion concentration in the test solution was compared (28.7 μM);

[0054] In this embodiment, the detected concentration value of chromate ions in the solution to be tested is 28.7 μM, and the actual concentration value is 30 μM, with an error of 4.3%.

[0055] Example 4: The difference between this example and Example 1 is that the concentration of chromate ions in the solution to be tested is 600 μM;

[0056] The test solution was tested by the same method as in Example 1, and the measured fluorescence image of the Eu-MOF test paper after immersion was captured by the intelligent terminal, and the measured RGB values ​​(194.5, 56.2, 131.8) of the measured fluorescence image were extracted, and the measured B / R value (0.68) was calculated at the same time. According to the measured B / R value and the B / R value-chromate ion concentration standard curve, the chromate ion concentration in the test solution was compared (586 μM);

[0057] In this embodiment, the detected concentration value of chromate ions in the solution to be tested is 586 μM, and the actual concentration value is 600 μM, with an error of 2.3%.

[0058] Example 5: A method for rapidly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on a smart terminal, the specific steps are as follows:

[0059] (1) A series of standard gradient concentration mercury ion solutions (concentrations were 0 μM, 5 μM, 10 μM, 20 μM, 30 μM, 40 μM, and 50 μM) were prepared, and the Eu-MOF test strips were immersed in the standard gradient concentration mercury ion solutions (immersion for 15 min). Under ultraviolet light, the fluorescent images of the Eu-MOF test strips after immersion were captured by the smart terminal (see Figure 5 );

[0060] The fluorescence response of Eu-MOF to different concentrations of mercury ions is shown in Figure 3 ,from Figure 3 It can be seen that the fluorescence intensity of the Eu-MOF suspension gradually decreases with the increase of mercury ion concentration, indicating that Eu-MOF has the ability to detect mercury ions;

[0061] (2) Extract the RGB values ​​of the fluorescence images corresponding to mercury ion solutions of different concentrations, and calculate the B / R value. According to the B / R value and the corresponding mercury ion concentration, establish a B / R value-mercury ion concentration standard curve (see Figure 7 ),from Figure 7 It can be seen that there is a linear relationship between the B / R value and the mercury ion concentration. Based on this standard curve, the mercury ion concentration can be directly obtained by measuring the B / R value;

[0062] (3) The Eu-MOF test paper was immersed in a solution with a mercury ion concentration (20 μM) to be tested (15 min), and the measured fluorescence image of the Eu-MOF test paper after immersion was captured by a smart terminal under the irradiation of an ultraviolet light source (370 nm) (see Fig.10 ), extract the measured RGB values ​​(212.4, 20.8, 75.0) of the fluorescence image, and calculate the measured B / R value (0.353). According to the measured B / R value and the B / R value-mercury ion concentration standard curve, the mercury ion concentration in the test solution (19.2 μM) is obtained by comparison;

[0063] In this embodiment, the detected concentration value of mercury ions in the solution to be tested is 19.2 μM, and the actual concentration value is 20 μM, with an error of 4%.

[0064] Example 6: The difference between this example and Example 1 is that the solution to be tested contains mercury ions (concentration of 30 μM), potassium ions (concentration of 50 μM), gold sodium ions (concentration of 50 μM), and aluminum ions (concentration of 50 μM);

[0065] The same method as in Example 1 was used to detect the test solution, and the measured fluorescence image of the Eu-MOF test paper after immersion was captured by the smart terminal (see Fig.11 ), extract the measured RGB values ​​(223.4, 23.2, 110.0) of the measured fluorescence image, and calculate the measured B / R value (0.492). According to the measured B / R value and the B / R value-mercury ion concentration standard curve, the mercury ion concentration in the test solution (28.5 μM) is obtained by comparison;

[0066] In this embodiment, the detected concentration value of mercury ions in the solution to be tested is 28.5 μM, and the actual concentration value is 30 μM, with an error of 5%.

[0067] Example 7: The difference between this example and Example 5 is that the mercury ion concentration in the test solution is 50 μM;

[0068] The test solution was tested by the same method as in Example 5. The measured fluorescence image of the Eu-MOF test paper after immersion was captured by the intelligent terminal, and the measured RGB values ​​(177.4, 36.9, 150.8) of the measured fluorescence image were extracted. The measured B / R value (0.850) was calculated at the same time. According to the measured B / R value and the B / R value-mercury ion concentration standard curve, the mercury ion concentration in the test solution (52 μM) was obtained by comparison;

[0069] In this embodiment, the detected concentration value of mercury ions in the solution to be tested is 52 μM, and the actual concentration value is 50 μM, with an error of 4%.

[0070] The specific implementation modes of the present invention are described in detail above, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for rapidly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal, characterized in that: The specific steps are as follows: (1) preparing a series of chromate ion solutions or mercury ion solutions with standard gradient concentrations, respectively immersing the Eu-MOF test paper in the chromate ion solutions or mercury ion solutions with standard gradient concentrations, and photographing the fluorescence image of the Eu-MOF test paper after immersion through an intelligent terminal under ultraviolet light; (2) extracting the RGB values ​​of the fluorescence images corresponding to the chromate ion solutions of different concentrations, calculating the B / R values, and establishing a B / R value-chromate ion concentration standard curve according to the B / R values ​​and the corresponding chromate ion concentrations; or extracting the RGB values ​​of the fluorescence images corresponding to the mercury ion solutions of different concentrations, calculating the B / R values, and establishing a B / R value-mercury ion concentration standard curve according to the B / R values ​​and the corresponding mercury ion concentrations; (3) The Eu-MOF test paper is immersed in a solution of the chromate ion concentration to be tested, and under the irradiation of an ultraviolet light source, a fluorescent image of the Eu-MOF test paper after immersion is captured by an intelligent terminal, and the measured RGB value of the fluorescent image is extracted, and the measured B / R value is calculated at the same time. The chromate ion concentration in the solution to be tested is obtained by comparison based on the measured B / R value and the B / R value-chromate ion concentration standard curve; or, the Eu-MOF test paper is immersed in a solution of the mercury ion concentration to be tested, and under the irradiation of an ultraviolet light source, a fluorescent image of the Eu-MOF test paper after immersion is captured by an intelligent terminal, and the measured RGB value of the fluorescent image is extracted, and the measured B / R value is calculated at the same time. The mercury ion concentration in the solution to be tested is obtained by comparison based on the measured B / R value and the B / R value-mercury ion concentration standard curve.

2. According to claim 1, the method for rapidly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal is characterized in that: Step (1) Preparation method of Eu-MOF detection test paper, the specific steps are as follows: 1) Eu(NO3)3·6H2O, [2,2'-biquinoline]-4,4'-dicarboxylic acid and 1,10-phenanthroline are mixed and dissolved in a solvent to obtain a mixed solution, the mixed solution is added into a sealed high-pressure reactor, hydrothermally reacted at a temperature of 120-140°C for 70-80h, cooled to room temperature, solid-liquid separation, and the solid is washed and dried to obtain the product Eu-MOF; 2) grinding the product Eu-MOF to obtain Eu-MOF powder, and ultrasonically dispersing the Eu-MOF powder into anhydrous ethanol to obtain a Eu-MOF suspension; 3) Soak the fiber filter paper in the Eu-MOF suspension, ultrasonically treat for 5 to 10 minutes, take out and dry, repeat the soaking-drying process to obtain the Eu-MOF detection test paper.

3. The method for rapidly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal according to claim 2, characterized in that: Step 1) The solvent is N,N-dimethylformamide; the molar ratio of Eu(NO3)3·6H2O, [2,2'-biquinoline]-4,4'-dicarboxylic acid and 1,10-phenanthroline is 1.8-2.1:1-3:

1.

4. The method for rapidly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal according to claim 3, characterized in that: Step 1) In the mixed solution, the concentration of Eu(NO3)3 is 10-20 mg / mL, the concentration of [2,2'-biquinoline]-4,4'-dicarboxylic acid is 5-30 mg / mL, and the concentration of 1,10-phenanthroline is 2-4 mg / mL.

5. The method for rapidly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal according to claim 2, characterized in that: Step 2) The particle size of the Eu-MOF powder is 5 to 30 μm, and the concentration of the Eu-MOF suspension is 0.1 to 5 mg / mL.

6. The method for rapidly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal according to claim 2, characterized in that: Step 3) The soaking time is 5 to 10 minutes.

7. The method for rapidly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal according to claim 1, characterized in that: The concentration gradient of the chromate ion solution in step (1) is 5 μmol / L, and the concentration range of a series of standard gradient concentrations of the chromate ion solution is 0 to 800 μmol / L; the concentration gradient of the mercury ion solution is 5 μmol / L, and the concentration range of a series of standard gradient concentrations of the mercury ion solution is 0 to 50 μmol / L.

8. The method for rapidly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal according to claim 1, characterized in that: The soaking time in step (1) is the same as that in step (3), and the wavelength of the ultraviolet light source is 360-375 nm.

9. The method for rapidly detecting the concentration of chromate ions or mercury ions in an aqueous solution based on an intelligent terminal according to claim 8, characterized in that: The soaking time is 5 to 20 minutes.

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