Application of pyrimidyl hydrazide compound in detection of copper ions or mercury ions

Abstract

The invention discloses application of a pyrimidyl hydrazide compound in detection of copper ions or mercury ions and a method for detecting the copper ions or the mercury ions. The pyrimidinyl hydrazide compound has a structural formula shown in the specification. The pyrimidinyl hydrazide compound N '-(2-pyrimidinyl) benzoyl hydrazine prepared by the invention is a dual-optical probe and can be used for detecting low-concentration bivalent copper ions or bivalent mercury ions in a water body.

Description

TECHNICAL FIELD

[0001] The application relates to the field of analytical detection technology, and particularly relates to application of a pyrimidyl hydrazide compound in detection of copper ions or mercury ions. BACKGROUND

[0002] With the acceleration of industrialization, more and more pollutants such as ions, organic small molecules, amino acids and antibiotics are discharged, which brings great harm to the environment and human beings. Transition metal ions are particularly common in various pollutants, so how to quickly and accurately detect and treat transition metal ions has become a problem that researchers urgently focus on. So far, people have adopted various detection ion analysis methods such as atomic absorption spectrometry (AAS), electrochemical method, inductively coupled plasma mass spectrometry (ICP-MS), X-ray absorption spectrometry and fluorescence spectrometry. Among them, the fluorescence method for detecting metal ions has the advantages of rapidness, simple operation, strong real-time detection capability and the like. So far, the application of fluorescence technology in ion detection has been well studied.

[0003] Copper and mercury, as important transition metals, are widely used in industry, but also bring serious environmental problems and many diseases to human beings. Excessive intake of the two ions can cause various symptoms, including hypoglycemia, gastric disease, cognitive impairment and kidney damage. Therefore, it is necessary to quickly and effectively detect copper and mercury ions. At present, there are many literatures about fluorescent chemical sensors for detecting copper ions and mercury ions. For example, the Chinese patent application document with the publication number CN115420723A discloses a probe for detecting Cu 2+ , the Chinese patent application document with the publication number CN118955324A discloses a probe for detecting Hg 2+ , but most of the probes are single probes, which can only detect Cu 2+ or can only detect Hg 2+ . Therefore, developing a dual probe that can be used for detecting Cu 2+ and Hg 2+ can expand the detection range. SUMMARY

[0004] The technical problem to be solved by the application is to provide a dual probe capable of detecting copper ions and mercury ions respectively.

[0005] The application solves the above technical problems by the following technical means:

[0006] The application relates to application of a pyrimidyl hydrazide compound in detection of copper ions or mercury ions, and the structural formula of the pyrimidyl hydrazide compound is

[0007] Preferably, the copper ion is a divalent copper ion; and the mercury ion is a divalent mercury ion.

[0008] Preferably, the pyrimidine hydrazide compound is used as a fluorescent probe.

[0009] Preferably, in the process of fluorescence detection, the excitation wavelength λ ex = 375 nm; and the fluorescence intensity of the emission wavelength λ em = 426 nm peak is read.

[0010] Preferably, the copper ion or the mercury ion is a copper ion or a mercury ion in water.

[0011] Preferably, in the application process, the pyrimidine hydrazide compound is prepared into a solution with DMSO as a solvent and then used.

[0012] Beneficial effects: The pyrimidine hydrazide compound of the present application has a large conjugate and can emit fluorescence in a solution such as dimethyl sulfoxide (DMSO), and is a dual optical probe for detecting low-concentration Cu 2+ or Hg 2+ by using solution fluorescence emission spectrum. The pyrimidine hydrazide compound as a fluorescent probe can detect trace amounts of Cu 2+ and Hg 2+ , and is a dual fluorescent probe for detecting metal ions.

[0013] Preferably, the concentration range of Cu 2+ to be detected is 5.0 × 10 -5 ~ 4.0 × 10 -4 mol L -1 .

[0014] Preferably, the concentration range of Hg 2+ to be detected is 1.0 × 10 -5 ~ 2.0 × 10 -4 mol L -1 .

[0015] The present application further provides a method for detecting copper ions or mercury ions by using a pyrimidine hydrazide compound, comprising the following steps:

[0016] S1, mixing a standard copper ion solution or a standard mercury ion solution and a DMSO solution of the pyrimidine hydrazide compound to obtain a mixed solution, performing fluorescence detection on the mixed solution to obtain a fluorescence intensity I, performing fluorescence detection on the DMSO solution of the pyrimidine hydrazide compound to obtain a fluorescence intensity I0, establishing a standard curve between the relative fluorescence intensity I0 / I and the concentration of the copper ion or the mercury ion to obtain a linear equation; wherein the structural formula of the pyrimidine hydrazide compound is

[0017] S2, mixing the to-be-tested copper ion solution or mercury ion solution with the DMSO solution of the pyrimidyl hydrazide compound, performing fluorescence detection, and calculating the concentration of the copper ion or mercury ion in the to-be-tested copper ion solution or mercury ion solution according to the linear equation.

[0018] Preferably, the concentration of Cu 2+ in the mixed solution for detection is 5.0*10 -5 ~4.0*10 -4 mol / L. -1 The linear equation I0 / I=0.98033+2.79688*10 3 C, wherein C is the concentration of Cu 2+ in the mixed solution for detection, is 1.0*10 -5 ~2.0*10 -4 mol / L. -1 The linear equation I0 / I=1.04946+3.48429*10 3 C, wherein C is the concentration of Hg 2+ in the mixed solution for detection, is 1.0*10 2+ ~2.0*10 -1 mol / L.

[0019] Preferably, in S1, the solvent of the standard copper ion solution or standard mercury ion solution is water; and in S2, the solvent of the to-be-tested copper ion solution or mercury ion solution is water.

[0020] Preferably, the concentration of the pyrimidyl hydrazide compound in the solution for fluorescence detection in S1 and S2 is 2.33*10 -3 mol / L. -1 .

[0021] Preferably, in the process of fluorescence detection in S1 and S2, the excitation wavelength λ ex =375nm.

[0022] Beneficial effects: the pyrimidyl hydrazide compound has good solubility in DMSO solvent and large fluorescence emission intensity.

[0023] Beneficial effects: the DMSO solution of the pyrimidyl hydrazide compound has good linear relationship between the relative fluorescence intensity I0 / I and the concentration of copper ion or mercury ion in a specific ion concentration range when detecting copper ion or mercury ion by fluorescence.

[0024] Preferably, in the process of fluorescence detection in S1 and S2, the fluorescence intensity of the peak of the emission wavelength λ em =426nm is read.

[0025] Preferably, the to-be-tested copper ion solution or mercury ion solution is a copper nitrate aqueous solution or a mercury nitrate aqueous solution.

[0026] The fluorescent probe is applied in actual detection, and the water sample to be detected does not contain only single metal ions, but often contains multiple ions in a mixed state, and the anti-interference ability is one of important indexes for evaluating the probe. 3+ , Co 2+ , Cr 3+ , Cd 2+ , K + , Ni 2+ , Pb 2+ , Mn 2+ , Ca 2+ , Zn 2+ , Fe 3+ , and the like.

[0027] Preferably, the 2-hydrazinylpyrimidine is acylated with benzoyl chloride to obtain the N'-(2-pyrimidinyl) benzoyl hydrazine pyrimidine compound

[0028] Preferably, the reaction temperature is controlled in the range of 0-20 DEG C, the reaction solvent is a mixture of one or more of dichloromethane, trichloromethane and carbon tetrachloride, and the reaction time is 2-4 hours.

[0029] Preferably, the molar ratio of the 2-hydrazinylpyrimidine to benzoyl chloride is 1:1.2-2.

[0030] Preferably, the reaction raw material further comprises triethylamine, and the molar ratio of the 2-hydrazinylpyrimidine, triethylamine and benzoyl chloride is 1:1.5-3:1.2-2.

[0031] Preferably, the specific process of acylating the 2-hydrazinylpyrimidine with benzoyl chloride to obtain the N'-(2-pyrimidinyl) benzoyl hydrazine comprises the following steps: dissolving the 2-hydrazinylpyrimidine and triethylamine with a solvent, adding a solution containing benzoyl chloride dropwise under nitrogen protection at 0-20 DEG C, stirring the reaction at 0-20 DEG C for 2-4 hours after the dropwise addition is completed, filtering after the reaction is completed, recrystallizing and drying to obtain the N'-(2-pyrimidinyl) benzoyl hydrazine.

[0032] The present application has the following advantages:

[0033] The pyrimidine hydrazide compound N'-(2-pyrimidinyl) benzoyl hydrazine in the present application has a simple synthesis method and mild reaction conditions. The compound can be used as a fluorescent double probe to detect low-concentration Cu 2+ or Hg 2+ in water, and has good anti-interference ability. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The solid infrared spectrum (KBr tablet) of N'-(2-pyrimidinyl) benzoyl hydrazine prepared in Example 1 of the present application;

[0035] Figure 2 The negative state mass spectrum of N'-(2-pyrimidinyl) benzoyl hydrazine prepared in Example 1 of the present application;

[0036] Figure 3 The nuclear magnetic resonance hydrogen spectrum (400 MHZ, deuterated DMSO as solvent, tetramethylsilane as internal standard) of N'-(2-pyrimidinyl) benzoyl hydrazine prepared in Example 1 of the present application;

[0037] Figure 4 The nuclear magnetic resonance carbon spectrum (400 MHZ, deuterated DMSO as solvent, tetramethylsilane as internal standard) of N'-(2-pyrimidinyl) benzoyl hydrazine prepared in Example 1 of the present application;

[0038] Figure 5 The fluorescence emission spectrum of N'-(2-pyrimidinyl) benzoyl hydrazine / DMSO solution with a concentration of 2.33 x 10 -3 mol L -1 at an excitation wavelength of 375 nm, in which the data indicated by the arrow is the concentration of added divalent copper ions;

[0039] Figure 6 The fluorescence emission intensity column chart of N'-(2-pyrimidinyl) benzoyl hydrazine / DMSO solution with a concentration of 2.33 x 10 -3 mol L -1 at an excitation wavelength of 375 nm, at an emission wavelength of 426 nm, in which other metal ions interfere with the divalent copper ions, in Example 3 of the present application;

[0040] Figure 7 The linear relationship chart of the relative fluorescence intensity I0 / I value and the concentration (C) of the detected substance when detecting divalent copper ions from N'-(2-pyrimidinyl) benzoyl hydrazine / DMSO solution with a concentration of 2.33 x 10 -3 mol L -1 at an excitation wavelength of 375 nm, at an emission wavelength of 426 nm, in Example 4 of the present application;

[0041] Figure 8 The fluorescence emission spectrum of N'-(2-pyrimidinyl) benzoyl hydrazine / DMSO solution with a concentration of 2.33 x 10 -3 mol L -1 at an excitation wavelength of 375 nm, in which the data indicated by the arrow is the concentration of added divalent mercury ions, in Example 5 of the present application.

[0042] Figure 9 The concentration in Example 6 of this invention is 2.33 × 10⁻⁶. -3 mol L -1 In a solution of N'-(2-pyrimidinyl)benzoylhydrazide / DMSO, the fluorescence emission intensity bar graph of other metal ions interfering with divalent mercury ions was measured at an emission wavelength of 426 nm using 375 nm as the excitation wavelength.

[0043] Figure 10 In Example 7 of this invention, the excitation wavelength was 375 nm, the emission wavelength was 426 nm, and the concentration was 2.33 × 10⁻⁶. -3 mol L -1 Linear relationship between relative fluorescence intensity I0 / I value and analyte concentration (C) when detecting divalent mercury ions with N'-(2-pyrimidinyl)benzoylhydrazine / DMSO solution;

[0044] Figure 11 The concentration in Comparative Example 2 of this invention is 2.33 × 10⁻⁶. -3 mol L -1 Fluorescence emission spectrum of N'-(2-pyrimidinyl)benzoylhydrazide / DMSO solution after the addition of metal ions at an excitation wavelength of 375 nm;

[0045] Figure 12 In Comparative Example 3 of this invention, carbon tetrachloride (CCl4), carbon disulfide (CS2), N,N-dimethylformamide (DMF), ethyl acetate (EA), nitrobenzene (NB), tetrahydrofuran (THF), aniline, pyridine, acetone, methanol (MeOH), ethanol (EtOH), acetonitrile (AeCN), and dimethyl sulfoxide (DMSO) were used, with a concentration of 2.33 × 10⁻⁶. -3 mol L -1 Fluorescence emission spectrum of N'-(2-pyrimidinyl)benzoylhydrazine with excitation wavelength of 375 nm. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] The test materials and reagents used in the following examples, and the like, can be obtained from commercial sources, unless otherwise specified.

[0048] The specific techniques or conditions not mentioned in the examples can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0049] Example 1

[0050] A method for preparing a pyrimidyl hydrazide compound, N'-(2-pyrimidyl) benzhydrazide, is shown in the following reaction scheme:

[0051]

[0052] Wherein: TEA is the abbreviation of triethylamine; DCM is the abbreviation of dichloromethane.

[0053] Specifically comprising the following steps:

[0054] Synthesis of N'-(2-pyrimidyl) benzhydrazide: 2-hydrazinylpyrimidine (4.40 g, 0.04 mol), triethylamine (6.074 g, 0.06 mol) were placed in a 150 mL three-necked flask equipped with a reflux condenser, and dissolved in 40 ml of dichloromethane. Benzoyl chloride (6.720 g, 0.048 mol) was dissolved in 40 ml of dichloromethane, and added dropwise into the above three-necked flask under magnetic stirring and nitrogen protection at 5°C. After the dropwise addition was completed, the reaction was continued to stir at 8°C for 2 hours. After the reaction was completed, the mixture was filtered, and the filter cake was recrystallized with 30 mL of a mixed solvent of ethyl acetate: petroleum ether = 1:2 (by volume ratio) to obtain 5.949 g of N'-(2-pyrimidyl) benzhydrazide solid, with a product yield of 69.5% based on 2-hydrazinylpyrimidine. Figures 1-4 The solid infrared spectrum (KBr pressed tablet), negative ion mass spectrum, nuclear magnetic resonance hydrogen spectrum (400 MHZ, deuterated DMSO as solvent, tetramethylsilane as internal standard), and nuclear magnetic resonance carbon spectrum (400 MHZ, deuterated DMSO as solvent, tetramethylsilane as internal standard) of N'-(2-pyrimidyl) benzhydrazide prepared in Example 1, respectively, are as follows: The main data of the infrared and nuclear magnetic resonance of N'-(2-pyrimidyl) benzhydrazide are as follows: IR: 3293 cm -1 , 3258 cm -1 , 3082 cm -1 , 1659 cm -1 , 1509 cm -1 , 1455 cm -1 , 791 cm -1 , 714 cm -1 . 1H NMR (400MHz, DMSO-d6) δ: 10.4~10.3(s,1H),9.1(d,1H),8.4(d,2H),7.9~7.8(m,2H),7.6~7.5(m,1H),7.5(t,2H),6.8(t,1H). 13 C NMR (400MHz, DMSO-d6) δ: 166.5, 163.8, 158.6, 133.3, 132.1, 128.9, 127.9, 113.0. (From...) Figures 1-4 It was deduced that the synthesized compound was the target substance.

[0055] Example 2

[0056] The pyrimidinyl hydrazide compound prepared in Example 1 was used as a fluorescent probe to detect low concentrations of Cu. 2+ .

[0057] 2.0 mg of the pyrimidinyl hydrazide compound was added to DMSO solvent and ultrasonically dispersed to prepare a solution with a concentration of 2.33 × 10⁻⁶. -3 mol L -1 The solution was prepared by adding 2 mL of the above solution to a cuvette and analyzing it using a Hitachi F-4500 fluorescence spectrometer at λ. ex Excitation was performed at 375 nm (excitation wavelength), and the fluorescence emission spectrum was measured. Then, 1 μL (0.1 mol / L) of a prepared aqueous solution of copper nitrate was added sequentially, and the fluorescence emission spectrum of the solution at the excitation wavelength of 375 nm was measured each time. The results are as follows: Figure 5 As shown, by Figure 5 It can be seen that with Cu 2+ As the ion concentration increases, the fluorescence intensity of the solution decreases rapidly, especially when Cu... 2+ The amount of ions added was 9.5 × 10⁻⁶. - 4 moL L -1 At that time, the fluorescence emission intensity of the solution changed very little.

[0058] Example 3

[0059] 2.0 mg of the pyrimidinyl hydrazide compound from Example 1 was added to DMSO solvent and ultrasonically dispersed to prepare a solution with a concentration of 2.33 × 10⁻⁶. -3 mol L -1 The solution was prepared by injecting 2 mL of the above solution into a cuvette and measuring the wavelength of the solution at λ using a Hitachi F-4500 fluorescence spectrometer with an excitation wavelength of 375 nm. em =Fluorescence intensity at 426nm (emission wavelength). Continue adding 20μL (0.1mol / L) of Cu removal solution. 2+ and Hg 2+The fluorescence intensity of aqueous solutions containing nitrates of other metals was measured at an emission wavelength of 426 nm. The results are as follows: Figure 6 As shown by the addition of pyrimidinyl hydrazide and other metal ions, 20 μL (0.1 mol / L) of copper nitrate aqueous solution was added, and the emission wavelength λ of the mixed ionic solution was measured. em The fluorescence intensity at 426 nm is shown in the following results. Figure 6 Medium pyrimidine hydrazide + other metal ions + Cu 2+ As shown, by Figure 6 It can be seen that other metal ions (Al) 3+ Co 2+ Cr 3+ Cd 2+ K + Ni 2+ Pb 2+ Mn 2+ Ca 2+ Zn 2+ Fe 3+ ) for Cu 2+ The fluorescence detection was largely unaffected. In the figure, the absence of ions in the pyrimidinyl hydrazide + other metal ions refers to a concentration of 2.33 × 10⁻⁶. -3 mol L -1 Fluorescence intensity of pyrimidinyl hydrazide compounds in DMSO solution; pyrimidinyl hydrazide + other metal ions + Cu 2+ The absence of ions in this context refers to a concentration of 2.33 × 10⁻⁶. - 3 mol L -1 Cu was added to the DMSO solution of the pyrimidinyl hydrazide compound. 2+ The fluorescence intensity without the addition of any other ions.

[0060] Example 4

[0061] Using the pyrimidinyl hydrazide compound prepared in Example 1 as a fluorescent probe, the detection of Cu in the pyrimidinyl hydrazide compound / DMSO solution was determined. 2+ The relative fluorescence intensity I0 / I value of Cu during ionization and the detection of Cu 2+ The relationship between concentration (C).

[0062] 2.0 mg of the pyrimidinyl hydrazide compound was added to DMSO solvent and ultrasonically dispersed to prepare a solution with a concentration of 2.33 × 10⁻⁶. -3 mol L -1The solution was prepared as follows. 2 mL of the above solution was injected into a cuvette, and the fluorescence emission spectrum was measured using a Hitachi F-4500 fluorescence spectrometer at λex = 375 nm (excitation wavelength). Then, 1 μL, 2 μL, 3 μL, 4 μL, 6 μL, 7 μL, and 8 μL of a prepared copper nitrate aqueous solution (0.1 mol / L) were added sequentially, and the fluorescence intensity at an emission wavelength of 426 nm (excitation wavelength of 375 nm) was measured respectively. The relative fluorescence intensity (I0 / I) was then obtained (I0 and I are Cu, respectively). 2+ Fluorescence intensity at concentrations of 0 and C) and Cu 2+ The linear relationship between concentration (C) and measurement results are as follows: Figure 7 As shown in Table 1.

[0063] Table 1. Detection of Cu in pyrimidinyl hydrazide compounds / DMSO solution 2+ The linear relationship between the I0 / I value and the concentration of the analyte (C).

[0064] Equation Regression coefficients (R 2 )]]> Detection range of analyte (mol / L -1 ) [I0 / I = 0.98033 + 2.79688 x 10 3 C]] 0.99462 5.0 x 10 -5 ~ 4.0 x 10 -4 ]]>

[0065] The relative fluorescence intensity (I0 / I) measured above and Cu 2+ The relationship between concentration (C) and concentration (C) indicates that at 5.0 × 10⁻⁶ -5 ~4.0×10 -4 mol L -1 Fluorescence intensity within range and Cu 2+ The concentration showed a good linear relationship. This compound can be used as a fluorescent probe for the quantitative detection of low concentrations of Cu. 2+ .

[0066] Example 5

[0067] The pyrimidinyl hydrazide compound prepared in Example 1 was used as a fluorescent probe to detect low concentrations of Hg. 2+ .

[0068] 2.0 mg of the pyrimidinyl hydrazide compound was added to DMSO solvent and ultrasonically dispersed to prepare a solution with a concentration of 2.33 × 10⁻⁶. -3 mol L -1 The solution was prepared as follows. 2 mL of the above solution was injected into a cuvette, and the fluorescence emission spectrum was measured using a Hitachi F-4500 fluorescence spectrometer at an excitation wavelength of λex = 375 nm. Then, 1 μL of a prepared (0.1 mol / L) aqueous solution of mercuric nitrate was added sequentially, and the fluorescence emission spectra of the solution at an excitation wavelength of λex = 375 nm were measured each time. The results are as follows. Figure 8 As shown, by Figure 8 It can be seen that, with Hg 2+ As the ion concentration increases, the fluorescence intensity of the solution decreases rapidly, especially when Hg... 2+The amount of ions added was 8.5 × 10⁻⁶. -4 moL L -1 At that time, the fluorescence emission intensity of the solution changed very little.

[0069] Example 6

[0070] 2.0 mg of the pyrimidinyl hydrazide compound from Example 1 was added to DMSO solvent and ultrasonically dispersed to prepare a solution with a concentration of 2.33 × 10⁻⁶. -3 mol L -1 The solution was prepared. 2 mL of the above solution was injected into a cuvette, and the fluorescence intensity at λem = 426 nm (emission wavelength) was measured using a Hitachi F-4500 fluorescence spectrometer with an excitation wavelength of 375 nm. Then, 20 μL (0.1 mol / L) of Cu-removing agent was added. 2+ and Hg 2+ The fluorescence intensity of aqueous solutions containing nitrates of other metals was measured at an emission wavelength of 426 nm. The results are as follows: Figure 9 The mixture of pyrimidinyl hydrazide and other metal ions was then used. 20 μL (0.1 mol / L) of a mercuric nitrate aqueous solution was added, and the fluorescence intensity of the mixed ion solution at an emission wavelength of 426 nm was measured. The results are as follows: Figure 9 Medium pyrimidine hydrazide + other metal ions + Hg 2+ As shown, by Figure 9 It can be seen that other metal ions (Al) 3+ Co 2+ Cr 3+ Cd 2 + K + Ni 2+ Pb 2+ Mn 2+ Ca 2+ Zn 2+ Fe 3+ ) for Hg 2+ The fluorescence detection was largely unaffected; in the figure, the absence of ions in pyrimidinyl hydrazide + other metal ions refers to a concentration of 2.33 × 10⁻⁶. -3 mol L -1 The fluorescence intensity of the pyrimidinyl hydrazide compound in DMSO solution without the addition of any ions; pyrimidinyl hydrazide + other metal ions + Hg 2+ The absence of ions in this context refers to a concentration of 2.33 × 10⁻⁶. -3 mol L -1 In a DMSO solution of pyrimidinyl hydrazide compounds, only Hg was added. 2+ The fluorescence intensity without the addition of any of the other ions mentioned above.

[0071] Example 7

[0072] The pyrimidine hydrazide compound prepared in Example 1 was used as a fluorescent probe to determine the Hg 2+ relative fluorescence intensity I0 / I value of the pyrimidine hydrazide compound / DMSO solution when detecting Hg 2+ concentration (C).

[0073] 2.0 mg of the pyrimidine hydrazide compound was added to a DMSO solvent and ultrasonically dispersed to prepare a solution with a concentration of 2.33 x 10 -3 mol / L. -1 2 mL of the above solution was injected into a cuvette, and the fluorescence emission spectrum was determined using a Hitachi F-4500 fluorescence spectrometer with λex=375 nm (excitation wavelength). Then, 0.2 μL, 0.4 μL, 0.8 μL, 1 μL, 2 μL, 3 μL, and 4 μL of the prepared aqueous mercury nitrate solution (0.1 mol / L) were sequentially added, and the fluorescence intensity at an emission wavelength of 426 nm (excitation wavelength of 375 nm) was determined for each, to obtain the linear relationship between the relative fluorescence intensity (I0 / I) (I0 and I are the fluorescence intensities when the Hg 2+ concentration is 0 and C, respectively) and the Hg 2+ concentration (C). Figure 10 The results are shown in Table 2.

[0074] Table 2 Linear relationship between the I0 / I value of the pyrimidine hydrazide compound / DMSO solution and the concentration (C) of the detected Hg 2+

[0075] Equation Regression coefficients (R 2 )]]> Detection range of analyte (mol / L -1 ) [I0 / I = 1.04946 + 3.48429 x 10 3 C]] 0.99049 1.0 x 10 -5 ~ 2.0 x 10 -4 ]]>

[0076] The relationship between the relative fluorescence intensity (I0 / I) determined above and the Hg 2+ concentration (C) indicates that the fluorescence intensity has a good linear relationship with the Hg -5 concentration in the range of 1.0 x 10 -4 mol / L to 2.0 x 10 -1 mol / L. 2+ This compound can be used as a fluorescent probe to quantitatively detect low concentrations of Hg 2+ .

[0077] Comparative Example 1

[0078] Application No. 202311792107, entitled "An Oxadiazole Ketone Compound, Preparation Method Thereof, and Use in Detecting Fe 3+ ​A Chinese patent application document disclosing the application of this technology discloses a method for preparing an oxadiazolone compound by reacting 2-hydrazinopyrimidine with 4-nitrobenzoyl chloride to obtain 4-nitro-N'-(2-pyrimidinyl)benzoylhydrazine, followed by reaction with triphosgene. This compound is 5-(4-nitrophenyl)-3-(2-pyrimidinyl)-1,3,4'-oxadiazol-2(3H)-one, and only its fluorescence detection of Fe has been reported. 3+ The performance test cannot detect copper ions.

[0079] Comparative Example 2

[0080] The pyrimidinyl hydrazide compound prepared in Example 1 was used as a fluorescent probe to detect low concentrations of metal ions.

[0081] 2.0 mg of the pyrimidinyl hydrazide compound was added to DMSO solvent and ultrasonically dispersed to prepare a solution with a concentration of 2.33 × 10⁻⁶. -3 mol L -1 The solution was prepared as follows. 2 mL of the above solution was injected into a cuvette, and the fluorescence emission spectrum was measured using a Hitachi F-4500 fluorescence spectrometer at λex = 375 nm (excitation wavelength). Then, 20 μL (0.1 mol / L) of a prepared aqueous solution of one of the following nitrates (chromium nitrate, cobalt nitrate, aluminum nitrate, cadmium nitrate, ferric nitrate, potassium nitrate, nickel nitrate, lead nitrate, manganese nitrate, calcium nitrate, zinc nitrate, copper nitrate, and mercuric nitrate) was added, and the fluorescence emission spectra of each solution at the 375 nm excitation wavelength were measured. The results are as follows: Figure 11 As shown (where "no ions" refers to a concentration of 2.33 × 10⁻⁶), -3 mol L -1 The test curve of the pyrimidinyl hydrazide compound in DMSO solution without the addition of any ions was obtained from... Figure 11 It can be seen that at λem = 426 nm (λex = 375 nm), only Cu... 2+ and Hg 2+ The ion significantly quenches the fluorescence intensity of pyrimidinyl hydrazide solution, a property not found in other metal ions.

[0082] Comparative Example 3

[0083] Thirteen solvents, namely carbon tetrachloride (CCl4), carbon disulfide (CS2), N,N-dimethylformamide (DMF), ethyl acetate (EA), nitrobenzene (NB), tetrahydrofuran (THF), aniline, pyridine, acetone, methanol (MeOH), ethanol (EtOH), acetonitrile (AeCN), and dimethyl sulfoxide (DMSO), were used to prepare solutions of pyrimidinyl hydrazide compounds for detection. The specific steps included: adding 2.0 mg of the pyrimidinyl hydrazide compound prepared in Example 1 to each of the thirteen solvents, dispersing ultrasonically, and preparing solutions with a concentration of 2.33 × 10⁻⁶. -3 mol L -1 The solutions were then injected into cuvettes and excited with a Hitachi F-4500 fluorescence spectrometer at λex = 375 nm (excitation wavelength) to measure the corresponding fluorescence emission spectra.

[0084] Depend on Figure 12 It can be seen that, under consistent testing conditions, the fluorescence emission peak intensity of the pyrimidinyl hydrazide compound varies significantly in different solvents, with the highest emission intensity observed in DMSO. Furthermore, Tables 1 and 2 show that the DMSO solution of the pyrimidinyl hydrazide compound exhibits significant variations in Cu emission intensity. 2+ or Hg 2+ The relative fluorescence intensity of Cu at that time 2+ or Hg 2+ The concentration of Cu exhibits a good linear relationship within a specific concentration range, while a similar linear relationship cannot be obtained in other solvents, meaning that Cu cannot be quantitatively detected in other solvents. 2+ or Hg 2+ .

[0085] In practical applications, fluorescent probes are often used to detect water samples containing multiple metal ions, not just a single metal ion. Therefore, interference resistance is a crucial indicator for evaluating probes. Test results show that the prepared compound probe exhibits excellent resistance to interference from other ions, making it a highly practical method for detecting Cu. 2+ and Hg 2+ Fluorescent probes.

[0086] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. The application of a pyrimidinyl hydrazide compound in the detection of copper or mercury ions, wherein the structural formula of the pyrimidinyl hydrazide compound is as follows:

2. The application of the pyrimidinyl hydrazide compound according to claim 1 in the detection of copper ions or mercury ions, characterized in that: The copper ions are divalent copper ions; the mercury ions are divalent mercury ions.

3. The application of the pyrimidinyl hydrazide compound according to claim 1 in the detection of copper ions or mercury ions, characterized in that: The pyrimidinyl hydrazide compound is used as a fluorescent probe.

4. The application of the pyrimidinyl hydrazide compound according to claim 3 in the detection of copper ions or mercury ions, characterized in that: During fluorescence detection, the excitation wavelength λ ex =375nm; Read the emission wavelength λ em =Fluorescence intensity at a peak of 426 nm.

5. The application of the pyrimidinyl hydrazide compound according to claim 1 in the detection of copper ions or mercury ions, characterized in that: The copper ions or mercury ions mentioned are copper ions or mercury ions in water.

6. The application of the pyrimidinyl hydrazide compound according to claim 1 in the detection of copper ions or mercury ions, characterized in that: In the application process, the pyrimidinyl hydrazide compound is prepared into a solution using DMSO as a solvent before use.

7. The application of the pyrimidinyl hydrazide compound according to claim 6 in the detection of copper ions or mercury ions, characterized in that: Detection of Cu 2+ The concentration range is 5.0 × 10⁻⁶. -5 ~4.0×10 -4 mol L -1 .

8. The application of the pyrimidinyl hydrazide compound according to claim 6 in the detection of copper ions or mercury ions, characterized in that: Hg detection 2+ The concentration range is 1.0 × 10⁻⁶. -5 ~2.0×10 -4 mol L -1 .

9. A method for detecting copper or mercury ions using a pyrimidinyl hydrazide compound, characterized in that: Includes the following steps: S1. A mixture is prepared by mixing a standard copper ion solution or a standard mercury ion solution with a DMSO solution of a pyrimidinyl hydrazine compound. The mixture is subjected to fluorescence detection to obtain fluorescence intensity I, and the DMSO solution of the pyrimidinyl hydrazine compound is subjected to fluorescence detection to obtain fluorescence intensity I0. A standard curve is established between the relative fluorescence intensity I0 / I and the concentration of copper or mercury ions to obtain a linear equation. The structural formula of the pyrimidinyl hydrazine compound is as follows: S2. Mix the copper ion solution or mercury ion solution to be tested with a DMSO solution of a pyrimidinyl hydrazine compound, perform fluorescence detection, and calculate the concentration of copper ions or mercury ions in the copper ion solution or mercury ion solution to be tested according to the linear equation.

10. The method for detecting copper or mercury ions using a pyrimidinyl hydrazine compound according to claim 9, characterized in that: Cu in the mixture being tested 2+ The concentration range is 5.0 × 10⁻⁶. -5 ~4.0×10 -4 mol L -1 The linear equation is I0 / I = 0.98033 + 2.79688 × 10⁻⁶. 3 C, Hg in the mixture being tested 2+ The concentration range is 1.0 × 10⁻⁶. -5 ~2.0×10 -4 mol L -1 The linear equation is I0 / I = 1.04946 + 3.48429 × 10⁻⁶. 3 C, where C in the equation is Cu 2+ or Hg 2+ Concentration, in mol / L -1 .

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