A compound, and a method of preparing and using the same

Abstract

The present application relates to a kind of compound and its preparation method and purposes, with isophthalic acid and 4-(diethylamino)salicylaldehyde as precursor, respectively through esterification, hydrazinolysis, amide synthesis 4-diethylsalicylaldehyde isophthalic hydrazone, it is a new acylhydrazone compound.It is dissolved in acetonitrile solution to obtain acylhydrazone solution, Pb 2+ After being added, the acylhydrazone solution appears an absorption peak at 505nm, and other common metal ions have little interference, so it can be used in the ultraviolet-visible analysis of Pb ion, with higher accuracy and sensitivity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heavy metal ion detection, in particular to a compound, a preparation method and application thereof. BACKGROUND

[0002] Industrial wastewater rich in heavy metal ions (such as Pb 2+ , Hg 2+ , Cr 3+ , etc.) can be deposited in organisms through the food chain after being discharged, causing great harm to humans and the natural environment. Lead (Pb) is a toxic metal that can accumulate in human and animal tissues. Excessive intake of lead can cause anemia, neurological disorders, and kidney damage. Currently, traditional analysis techniques for detecting Pb ions mainly include atomic emission spectrometry (AES) and inductively coupled plasma mass spectrometry (ICP-MS) based on large instruments. These detection methods have high accuracy, but require precise instruments, professional operators, and complex sample pretreatment procedures, and are expensive, limiting their application in rapid detection. Therefore, the design and synthesis of receptor molecules with selective recognition function for Pb ions have attracted much attention in recent years.

[0003] As one of the most widely used ligands in coordination chemistry, Schiff bases have a special C=N structure. At the same time, the stability of the complexes formed by Schiff bases with metal ions is different due to the different substituents on the Schiff bases. Therefore, Schiff bases are often introduced into the structure of metal ion fluorescence and visible light probes as groups for recognizing metal ions.

[0004] Phthalhydrazide has a good signal reporting group, and salicylaldehyde has a hydroxyl group that can provide electrons. The conjugated system of the Schiff base formed by their combination is extended, has multiple coordination sites, and has a molar extinction coefficient of 10 4 L·mol*cm -1 The above has high sensitivity, large contrast, good color development, and recognition ability. Zhang Youming et al. (Synthesis of Phthalhydrazide Derivatives and Anion Recognition, Applied Chemistry, 2009, 26(11), 1253-1258; Synthesis and Anion Recognition of Phthalhydrazide Compounds, Chemical Reagents, 2009, 31(5), 321-323) studied the recognition of anions by phthalhydrazide Schiff bases. The results showed that these Schiff bases can achieve naked-eye detection of F - and Ac - .

[0005] However, the recognition of anions by phthalhydrazide Schiff bases has limitations, and it is currently not applicable to the recognition of cations, so it cannot be used for Pb ion detection at the present stage. SUMMARY

[0006] The object of the present application is to overcome the deficiencies of the prior art, to synthesize a new visible light probe (4-diethyl salicylaldehyde m-phthaldehyde hydrazone Schiff base) using m-phthaldehyde hydrazine and salicylaldehyde derivatives as precursors, which can selectively recognize Pb ions, including monovalent, divalent, trivalent, tetravalent and pentavalent Pb ions, and can be used in the detection of practical samples such as vegetables.

[0007] The current national standard uses dithizone colorimetry as a visible light detection method for Pb ions. This method uses dithizone as a chromogenic reagent, which is easily oxidized and easily interfered by iron ions, zinc ions and copper ions in the sample. The chromogenic reagent containing 4-diethyl salicylaldehyde m-phthaldehyde hydrazone Schiff base in the present application has higher stability than dithizone and is less affected by other metal ions in the sample. Among them, the interference of zinc ions can be ignored. At the same time, the response value of the compound to Pb ions is 8-10 times that of copper ions, so it can be used for common water, soil and food sample detection without interference from copper ions.

[0008] The specific scheme is as follows:

[0009] A compound, the structural formula of which is as follows:

[0010]

[0011] Further, the melting point of the compound is 270-285℃.

[0012] Further, the melting point of the compound is 275-282℃.

[0013] Further, the compound has infrared absorption peaks at at least one of the following: 1633cm -1 , 1587cm -1 , 1517cm -1 , 1414cm -1 , 1348cm -1 , 1253cm -1 , 1132cm -1 , 964cm -1 , 786cm -1 , 719cm -1 .

[0014] The application also protects a preparation method of the compound, which comprises: mixing isophthalic dihydrazide, 4-diethylaminosalicylaldehyde and a catalyst in a solvent to obtain a turbid liquid, heating the turbid liquid to reflux to generate a yellow precipitate; cooling the reaction system and filtering while cold, and recrystallizing the obtained solid to obtain yellow granular crystals, which are the compound.

[0015] Further, the catalyst is an acidic reagent, preferably any one of hydrochloric acid, sulfuric acid and glacial acetic acid.

[0016] Further, the solvent is an alcohol, preferably any one of methanol, ethanol, propanol and butanol.

[0017] Further, the heating reflux temperature is 80-100 DEG C, preferably 85-90 DEG C; and the heating reflux time is 2-10 h, preferably 4-6 h.

[0018] Preferably, the cooling temperature is-10-10 DEG C, more preferably-5-5 DEG C.

[0019] Preferably, the recrystallization uses methanol as the solvent.

[0020] The application also protects the use of the compound in Pb ion detection.

[0021] Beneficial effects: the application provides a new compound, which can be named 4-diethylaminosalicylaldehyde isophthalic dihydrazide according to systematic nomenclature, the acylhydrazone compound generates a new absorption peak at 505 nm only when Pb 2+ and Cu 2+ are introduced, and the response degree of Pb 2+ is much higher than that of Cu 2+ .

[0022] Further, the response equilibrium time of the acylhydrazone compound to Pb 2+ is 5 min, the linear range is 2.5-25 ppm, the Pb(II) detection limit is 0.78 ppm (3 sigma / k, n=11), and the compound can be used for detecting the Pb(II) content in water, soil and food (for example, mustard) samples, and the recovery rate is more than 90%. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the application, the following will briefly introduce the drawings. Obviously, the drawings described below only relate to some embodiments of the application, and not limit the application.

[0024] Figure 1is a synthesis schematic diagram of dimethyl isophthalate provided by one embodiment 1 of the present application;

[0025] Figure 2 is a dimethyl phthalate product photo provided by one embodiment 1 of the present application;

[0026] Figure 3 is an infrared standard spectrum of dimethyl isophthalate provided by one embodiment 1 of the present application;

[0027] Figure 4 is an infrared actual measurement spectrum of dimethyl isophthalate product provided by one embodiment 1 of the present application;

[0028] Figure 5 is a synthesis schematic diagram of isophthalic dihydrazide provided by one embodiment 1 of the present application;

[0029] Figure 6 is a recrystallized product photo of isophthalic dihydrazide provided by one embodiment 1 of the present application;

[0030] Figure 7 is an infrared standard spectrum of isophthalic dihydrazide provided by one embodiment 1 of the present application;

[0031] Figure 8 is an infrared actual measurement spectrum of isophthalic dihydrazide product provided by one embodiment 1 of the present application;

[0032] Figure 9 is a synthesis schematic diagram of 4-diethylaminosalicylaldehyde isophthalic dihydrazide provided by one embodiment 1 of the present application;

[0033] Figure 10 is a 4-diethylaminosalicylaldehyde isophthalic dihydrazide product crystallization photo provided by one embodiment 1 of the present application;

[0034] Figure 11 is a 4-diethylaminosalicylaldehyde isophthalic dihydrazide infrared spectrum provided by one embodiment 1 of the present application;

[0035] Figure 12 is a visible spectrum diagram of acylhydrazone mixed with various inorganic ions provided by one embodiment 2 of the present application (the concentration is 5.0×10 -5 mol / L);

[0036] Figure 13 is a kinetic response curve of acylhydrazone to Pb ions provided by one embodiment 2 of the present application (the concentration is 5.0×10 -5 mol / L);

[0037] Figure 14 is a standard curve of acylhydrazone to Pb ions provided by one embodiment of the present application, and the concentration of acylhydrazone is fixed as 5.0×10-5 mol / L. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present application will be described in more detail below. Although the preferred embodiments of the present application are described below, it is understood that the present application can be practiced with various modifications and that the embodiments illustrated should not be considered as limiting the scope of the application. Unless otherwise indicated, technical or conditions in the examples are carried out according to the techniques or conditions described in the literature or according to the product manual. Unless otherwise indicated, the reagents or instruments used are all conventional products that can be commercially available. In the following examples, unless otherwise specified, "%" means weight percent.

[0039] The main equipment used below is shown in Table 1:

[0040] Table 1 Main instruments for experiments

[0041]

[0042] The main reagents used below include:

[0043] Experimental reagents: 4-(diethylamino)salicylaldehyde, isophthalic acid, anhydrous ethanol, acetonitrile, methanol, concentrated sulfuric acid, hydrazine hydrate, glacial acetic acid, HgCl2, NiCl2, ZnCl2, PbCl2, MnCl2, CuCl2, FeCl3, AgNO3, KBr, NaF, CH3COONa, etc. are all from Sinopharm Group, all of which are analytical pure.

[0044] The solutions of acylhydrazone and various inorganic salts were prepared as stock solutions. Since the solubility of acylhydrazone in water is very low, acetonitrile was used as the solvent, and the concentration was 2.0 x 10 -4 mol / L, and was stored in the refrigerator. Other inorganic salts including ZnCl2, Cu(NO3)2, Pb(NO3)2, NiCl2, MnCl2, CoCl2, FeCl3, HgCl2, AgNO3, CH3COONa, NaF were all aqueous solutions. The concentration was 1.0 x 10 -3 mol / L, and was stored in a cool and dry place.

[0045] Example 1 Synthesis of 4-diethylsalicylaldehyde isophthalic hydrazone

[0046] The reagent was synthesized through three steps. First, isophthalic acid dimethyl ester was synthesized from isophthalic acid, then hydrazinolysis was performed to obtain isophthalic hydrazide, and finally condensation was performed to obtain 4-diethylamino salicylaldehyde isophthalic hydrazone, as follows:

[0047] (1) Synthesis of isophthalic acid dimethyl ester

[0048] The isophthalic acid dimethyl ester was synthesized by using 0.5 mL of concentrated sulfuric acid as catalyst, dissolving 1.66 g (10 mmol) of isophthalic acid in 20 mL of methanol, and heating to reflux for 20 h using a magnetic stirrer. After the reaction was completed, the solution was cooled in a refrigerator, and a large amount of white needle-shaped solid was precipitated. The solid was filtered while cold. The pH was adjusted to 7-8 using 0.8 mol / L aqueous sodium carbonate solution (no bubbles were generated), and the isophthalic acid dimethyl ester was recrystallized from methanol. The purified product (white needle-shaped crystals) was washed, filtered, and dried in an oven at a temperature of 40°C. The melting point and infrared spectrum of the product were determined. The synthesis scheme and appearance of the product are shown in Figs. 1 and 2, respectively. Figure 1 and Figure 2

[0049] The details of the synthesis of the isophthalic acid dimethyl ester include:

[0050] ① The magnetic heating stirrer used in this experiment was set to the third gear, and the speed was set to medium.

[0051] ② After heating and stirring for about 20 min, the solution became clear, and the reaction began.

[0052] ③ After the reaction was completed, the apparatus was turned off. The reaction flask contained a clear solution, which was cooled in a refrigerator. After being gently shaken and allowed to stand, a large amount of white needle-shaped solid was precipitated. This phenomenon indicated that the final solution was supersaturated at 4°C.

[0053] ④ The pH was adjusted to neutralize the added concentrated sulfuric acid, and the degree of neutralization was controlled so that no bubbles were generated.

[0054] ⑤ The recrystallization was performed using methanol, and the sample was covered with methanol.

[0055] ⑥ Because the isophthalic acid dimethyl ester was very fine, a large amount of the product could be lost during filtration. Therefore, filtration was used instead of suction filtration (filtration is preferably performed at low temperature). Of course, the number of filter paper layers can be increased during suction filtration to reduce the loss.

[0056] ⑦ The hot air drying at 40°C required more than 24 h to ensure complete drying. The dried isophthalic acid dimethyl ester was fine and needle-shaped.

[0057] The melting points of the synthesized isophthalic acid dimethyl ester were determined. Three samples were tested, and were numbered 1, 2, and 3. The results are shown in Table 2. The measured melting points were very close to the theoretical values, indicating that the purity of the synthesized ester was very high.

[0058] Table 2 Melting point determination of isophthalic acid dimethyl ester

[0059]

[0060] ​The infrared spectrum of the product was tested using KBr pellets, and the main vibrational peaks of the synthesized sample were assigned and listed in Table 3, and compared with standard spectra. It was found that the tested infrared spectra were basically consistent with the theoretical values, indicating that the product is dimethyl isophthalate.

[0061] Table 3 Infrared Analysis of Major Functional Groups of Dimethyl Isophthalate

[0062] Theoretical spectral absorption wavelength values (cm -1 )]]> Actual absorption wavelength values (cm -1 )]]> Functional group 1728 1729 -C=0 stretching vibration in esters 1607 1615 stretching vibration of C=C skeleton 1440 1442 -C-H stretching vibration in methyl group 1249 1244 -C-C(=0)-0 vibration in saturated ester 1078,1004 1076，1006 two -C-0 vibrations in ester 726 774 -C-H deformation vibration on benzene ring

[0063] (2) Synthesis of isophthalic acid hydrazide:

[0064] Dissolve 0.65 g of dimethyl isophthalate in 10.05 mL of methanol, then add approximately 2.033 mL of 80% hydrazine hydrate (ρ... 80％ =1.03 g / mL (excess may be appropriate), heat under reflux at 80-85℃ for 24 h (after the reaction, a small amount of white precipitate will remain at the bottom of the beaker or the mixture will be completely clear). Shake the flask after the reaction, cool with tap water, and then place it in a refrigerator to cool completely. After cooling, a large amount of white solid will precipitate. Filter while cold, wash with water, and thoroughly wash away the white solid. Place the white solid in a beaker, dissolve in water, heat until completely dissolved, cool naturally, and the solid will precipitate. Wash with a low-boiling-point reagent (e.g., methanol), and dry the residue at 60℃. Determine the melting point and infrared spectroscopy of the product. The synthesis diagram and product appearance are shown below. Figure 5 and Figure 6 As shown.

[0065] The solvent portion of the reaction solution was evaporated using a rotary vacuum evaporator at a vacuum of 0.1 MPa. The solution was dried at 40°C until no liquid evaporated. The temperature was then raised to 50°C and evaporated for another 5–10 minutes. The flask was washed with water, and the washed liquid was placed in a beaker and placed in a refrigerator to cool completely. The solution was filtered while cold and then dried in a 60°C oven. The melting point and infrared spectroscopy were then performed.

[0066] The relevant details of the above-mentioned synthesis process of isophthalohydrazide include:

[0067] ① This experiment uses a water bath, mainly for better temperature control. First, the water temperature is controlled at around 60℃. Dimethyl isophthalate and methanol are added to the flask and shaken to dissolve the ester. Then, 80% hydrazine hydrate is added, and the temperature is raised to 80-85℃ to start the reaction.

[0068] (2) The addition of 80% hydrazine hydrate should be done quickly and with a proper excess. Hydrazine hydrate is also known as hydrazine monohydrate, which is a strong base and hygroscopic. The pure product is a colorless transparent oily liquid with a faint ammonia smell, which smokes in the wet air, has strong basicity and hygroscopicity. It is particularly worth noting that it decomposes into N2, NH3 and H2 at high temperature (about 100°C). Therefore, the temperature should be properly increased to 100°C at the end of the reaction to remove excess hydrazine hydrate.

[0069] (3) During the recrystallization process, irritating gas may still appear, which is easily soluble NH3 at this time. NH3 is easily soluble in water, so the smell is particularly obvious during fast drying. After recrystallization, drying is performed, and white or white-like solid is obtained after drying. The solid is placed in a desiccator to prevent moisture, and the next step is performed. It is particularly important to note the temperature of drying, which should be kept at a low temperature to prevent oxidation caused by high temperature.

[0070] The melting point of the product is determined, and three synthesized samples are taken for testing, numbered 1, 2 and 3. The results are shown in Table 4, and the test values are close to the theoretical values, indicating that the synthesized material is the desired product.

[0071] Table 4 Melting point determination table of isophthalic dihydrazide

[0072]

[0073] The product is tested by KBr tabletting, the main vibration peaks are assigned, and are shown in Table 5, and are compared with the standard spectrum. By comparing the spectra, the characteristic peaks of the two spectra are similar, indicating that the product is isophthalic dihydrazide.

[0074] Table 5 Main functional group infrared analysis table of isophthalic dihydrazide

[0075]

[0076]

[0077] Note: The synthesis process of the above two reagents is only for reference and does not constitute a limitation on the present application. In other embodiments, commercially available products can also be used.

[0078] (3) Synthesis of 4-diethylaminosalicylaldehyde isophthaldehyde hydrazone:

[0079] 0.08 g of isophthalic dihydrazide, 0.20 g of 4-diethylaminosalicylaldehyde, 5 mL of glacial acetic acid were mixed in 7-10 mL of methanol, which was a turbid liquid at this time, and heated under reflux in a water bath at 85°C for 4 h, with yellow precipitate generated. The product was cooled in a refrigerator, with more solid precipitated, and filtered while cold, and recrystallized in methanol to obtain yellow granular crystals, which were the target product 4-diethylaminosalicylaldehyde isophthalic acid hydrazone, hereinafter referred to as acylhydrazone. The synthesis schematic diagram and product appearance are shown in Figure 9 and Figure 10 .

[0080] The relevant details of the above synthesis process are as follows:

[0081] 1. Theoretically, the amount of substance ratio required for the acylhydrazone generated by the reaction of hydrazide with aldehyde is aldehyde / hydrazide = 2. In the experiment, in order to improve the yield of acylhydrazone, the ratio of aldehyde to hydrazide can be increased to 2.5, at which time the yield is about 80% or so.

[0082] 2. Glacial acetic acid is used as a catalyst to speed up the reaction.

[0083] 3. Recrystallization with methanol, the product appears as yellow lustrous crystals, the solubility of the product in methanol is not high, but in order to ensure purity, multiple crystallization, batch crystallization can be used.

[0084] Two portions of the synthesized sample were taken, and the C, N, H element analysis of the synthesized acylhydrazone was performed, as shown in Table 6, which can be found that the theoretical value and the measured value are close.

[0085] Table 6 Element analysis results of acylhydrazone (molecular formula: C 30 H 36 N6O4 Molecular weight: 544.65)

[0086]

[0087] The melting point of acylhydrazone was measured, and the experimental results are as follows, and the related reports of the reagent cannot be found in the literature, and according to the molecular weight, the theoretical melting point is above 250°C, and according to the similar literature (Synthesis of isophthalic acid hydrazone derivatives and anion recognition, Applied Chemistry, 2009, 26(11), 1253-1258; Synthesis of isophthalic acid hydrazone compounds and anion recognition research, Chemical Reagents, 2009, 31(5), 321-323), the melting point of acylhydrazone with isophthalic acid as the mother body is greater than 270°C, and the measured value also verifies that the synthesized product is likely to be acylhydrazone.

[0088] Table 7 Melting point measurement results of acylhydrazone

[0089]

[0090] The infrared measurement results of acylhydrazone are as follows Figure 11The assignments of the peaks are shown in Table 8. The main functional groups of the acylhydrazone are found to have corresponding IR absorption peaks.

[0091] Table 8. IR vibration peak assignments of the main functional groups of 4-diethylamino salicylaldehyde-benzene dicarboxylic acylhydrazone

[0092] Product Absorption Wavelength cm -1 ]] Functional group 1633 stretching vibration of -C=0 on amide 1587 stretching vibration of -C=N in substituent on benzene ring 1517 bending vibration of -N-H in substituent 1414 stretching vibration of -C-N in amide 1348 stretching vibration of -C-N in aryl carbon 1253 stretching vibration of -C-0 in aromatic alcohol 1132 stretching vibration of -C-C in aromatic ketone group 964 stretching vibration of -C-0 in acid anhydride 786 deformation vibration of -C-H on benzene ring and meta disubstitution 719 deformation vibration of -N-H in amine

[0093] Example 2

[0094] The acylhydrazone prepared in Example 1 was prepared into an acylhydrazone stock solution and tested as follows:

[0095] (1) Absorption spectrum test of acylhydrazone and various metal ions

[0096] In a centrifuge tube, 0.75 mL of the acylhydrazone stock solution (2 x 10 -4 mol / L) was added, and 150 uL of various ion stock solutions (1.0 x 10 -3 mol / L) were added, including Zn(II), Cu(II), Ni(II), Mn(II), Co(II), Hg(II), Fe(III), NaAc and NaF, and acetonitrile was added to 3.0 mL, so that the concentration of each ion and acylhydrazone in the final solution was 5.0 x 10 -5 mol / L. The solution was allowed to stand in the dark for 20 min and tested by UV-Vis absorption spectrum, and the results are shown in Figure 12 It can be found that after the addition of Pb(II) ions, the acylhydrazone has a new absorption peak at 505 nm, with an absorbance of about 0.8, and the absorption of other single ions at this wavelength is less than 0.05.

[0097] Then, the spectrum of the mixture of the above ions (all at a concentration of 5.0 x 10 -5 mol / L) and acylhydrazone was tested, and the absorbance was much smaller than that of Pb(II) and acylhydrazone, indicating that the substance can selectively respond to Pb(II).

[0098] In addition, among the common transition metal ions, only the addition of Pb 2+ and Cu 2+ causes the acylhydrazone to have a new absorption peak at 505 nm, and the response degree of Pb 2+ is much higher than that of Cu 2+ , so the interference of copper ions can be avoided, and the detection of Pb(II) has high accuracy.

[0099] (2) Kinetic curve test

[0100] The absorbance of the acylhydrazone and Pb(II) solution at 505 nm was tested at different time points according to the above conditions, and the results are shown in Figure 13As shown, the acylhydrazone responds to Pb(II) quickly, and reaches equilibrium in about 5 minutes.

[0101] (3) Standard curve of Pb(II)

[0102] The concentration of the fixed acylhydrazone was 5.0 x 10 -5 mol / L, the fixed time was 5 minutes, the amount of Pb(II) was changed, the absorbance at 505 nm was tested, and the standard curve was drawn, as shown in Figure 14 , and the results are as follows:

[0103] When the molar ratio of Pb(II):L was 0.05-0.5, i.e. the concentration of Pb(II) was 2.5-25 ppm, the absorbance increased with the addition of Pb(II), and the linearity was good, the linear equation was y = 1.5342x-0.023, R 2 = 0.9979. When the molar ratio exceeded 0.5, the absorbance was basically stable at about 0.8, which may be that the combination of Pb(II) and acylhydrazone reached saturation, and further addition would not cause a change in absorbance. The detection limit of Pb(II) was calculated to be 0.78 ppm (3σ / k, n = 11).

[0104] As can be seen, the acylhydrazone responds to Pb 2+ with an equilibrium time of 5 minutes, a linear range of 2.5-25 ppm, and a detection limit of Pb(II) of 0.78 ppm (3σ / k, n = 11), and has high sensitivity.

[0105] Example 3 Determination of the content of Pb(II) in vegetable samples by acylhydrazone solution

[0106] 0.3 g of mustard sample was accurately weighed into a polytetrafluoroethylene digestion tank, 3 mL of concentrated nitric acid and 3 mL of hydrochloric acid were added, and the sample was pre-digested overnight, and then microwave digestion was performed according to the program of 150°C for 10 minutes, 180°C for 5 minutes, and 210°C for 30 minutes. After digestion, the sample was cooled, and then diluted to 25 mL with ultrapure water. 100 μL of the extract was added to the acylhydrazone solution prepared in Example 1 (using acetonitrile as the solvent, and the concentration of acylhydrazone was 2.0 x 10 -4 mol / L), and diluted to 3 mL with acetonitrile. After standing for 5 minutes, the absorbance at 505 nm was tested, the concentration was converted according to the standard curve, and the addition of Pb(II) was treated and calculated, and the results are shown in Table 9.

[0107] Table 9 Determination of the content of Pb(II) in mustard samples (three parallel tests)

[0108] Item Detection concentration (ppm) Recovery rate (%) Relative standard deviation (%) Treatment liquid Not detected Pb 2+ spiked (10 ppm) 9.6 96％ 0.8 Pb 2+ spiked (5 ppm) 5.0 94％ 0.4

[0109] The above experiments show that acylhydrazone is used for detecting the content of Pb(II) in mustard samples, and the recovery rate is more than 90%, which has high accuracy.

[0110] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the specific details in the above-described embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0111] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combinations are not described again by the present application.

[0112] In addition, various different embodiments of the present application can also be combined in any manner, as long as it does not deviate from the idea of the present application, and it should also be considered as disclosed by the present application.

Claims

1. The use of a compound in the detection of Pb(II), characterized in that: The compound has the following structural formula: It is used for the detection of Pb(II) content in water, soil and food samples, with a recovery rate of over 90%.

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