Specific detection method for organic phenol pollutants in water based on fluorescent ionic liquid

Abstract

The invention discloses a specific detection method for organic phenol pollutants in water based on a fluorescent ionic liquid, which comprises the following steps: adding the ionic liquid into an aqueous solution containing organic phenols, and immediately carrying out fluorescence detection to realize the detection of the organic phenols in the water body; the fluorescent ionic liquid compound is 3-methyl-1-naphthyl methylimidazole naphthoate, and the organic phenol pollutant is nonyl phenol. The method for detecting the nonyl phenol in the water body by using the fluorescent ionic liquid compound has the characteristics of convenience in operation, high sensitivity, short response time, low detection limit, good stability, high accuracy and the like.

Description

Technical Field

[0001] The invention relates to the preparation of fluorescent ionic liquid, in particular to a fluorescent ionic liquid with a binaphthalene ring structure and a synthesis method thereof. The compound is suitable for being used as a fluorescent probe to achieve specific detection of nonylphenol, an organic pollutant in water. Background Art

[0002] Phenol pollutants are common pollutants in water environments, among which nonylphenol is one of the alkylphenol compounds, and is also an important chemical raw material and intermediate product, which can be mainly used in the preparation of surfactants, detergents, medicine, agriculture and other industries and fields. Nonylphenol is a typical environmental hormone, and its structure and characteristics are similar to estrogen, which can interfere with the human endocrine system, poison the reproductive system, and thus endanger human health. At present, the detection of nonylphenol is basically based on traditional methods, such as high performance liquid chromatography, electrochemical method, gas chromatography, etc. These methods are often time-consuming or unstable. The prior art provides a specific detection method for organic pollutants in water based on fluorescent ionic liquids, which has the characteristics of convenient operation, high sensitivity, short response time, low detection limit, good stability, high accuracy, etc. At present, there is no relevant report on the detection of nonylphenol in water based on ionic liquids. Summary of the invention

[0003] One of the purposes of the present invention is to propose a method for detecting organic phenol pollutants in water based on fluorescent ionic liquids. The present invention can be applied to the specific detection of nonylphenol when the water contains different types of ions and other phenolic substances, and has very high practical value and development prospects.

[0004] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0005] A specific detection method for organic phenol pollutants in water based on fluorescent ionic liquids comprises the following steps: pretreatment of water samples, adding fluorescent ionic liquids containing a double naphthalene ring structure into the pretreated water sample containing nonylphenol, and immediately performing fluorescence detection; the fluorescent ionic liquids containing a double naphthalene ring structure are Ring structure.

[0006] In the present invention, the structure of the fluorescent ionic liquid is as follows:

[0007]

[0008] In the present invention, the organic phenol pollutant detected is nonylphenol.

[0009] In the present invention, the water is mixed with cations, anions and other phenolic substances, cations, such as Ni + 、Na+ , Ca 2 + , Fe 3+ , Cu 2+ , K + Mg 2+ 、Co + , Mn 2 , anions, such as: COO - 、H2PO4 - 、NO3 - , CI - 、SO4 2- , other phenols, such as: bisphenol A, bisphenol B, bisphenol S, estrone, 1,2-diphenol.

[0010] In the present invention, the pretreatment of the water sample includes centrifuging for 5 minutes, taking the supernatant, and filtering it through a 0.45-μm membrane filter.

[0011] In the present invention, the usage ratio of the fluorescent ionic liquid and the detected water body is: 200 μL: 1600 μL; the concentration of the fluorescent ionic liquid is 10 mmol / L; and the concentration of nonylphenol is 1-200 μmol / L.

[0012] In the present invention, the pH of the water body is 3-10, preferably pH=7.

[0013] The preparation method of the fluorescent ionic liquid of the present invention is:

[0014] (1) Tetrahydrofuran, 1-chloromethylnaphthalene and N-methylimidazole are added to the same three-necked flask, and after reflux at 70° C. for 16 h in a magnetic heating and magnetic stirrer, chloroform is added, and after purification, an imidazole salt intermediate, 1-methyl-3-methylnaphthylimidazole chloride, is obtained.

[0015] (2) Weigh NaOH in a beaker, add a small amount of water to make a NaOH solution with a concentration of 3 mol / L, transfer the prepared NaOH solution into a single-necked flask; then weigh 1-naphthoic acid and add it to the NaOH solution (NaOH is slightly excessive, the molar ratio of NaOH to 1-naphthoic acid is about 1.03:1), react at 30°C for 24 hours, and a yellow Sodium formate solution.

[0016] (3) Add the imidazole salt intermediate 1-methyl-3-methylnaphthoimidazole chloride to the 1-naphthoic acid sodium solution, keep the reaction at 50°C in a constant temperature heating magnetic stirrer for 24 hours, evaporate the water, transfer to a beaker, add anhydrous ethanol, freeze for 3 hours, take out, and filter. After purification and drying, the product 3-methyl-1-naphthomethylimidazol naphthoate is obtained.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] ① The present invention uses fluorescent ionic liquid compounds to detect nonylphenol in water with a low limit of 0.6 μmol / L.

[0019] ② The present invention is a specific detection method that can detect nonylphenol in water under complex environments.

[0020] ③ The present invention provides a specific detection method for organic phenol pollutants in water based on fluorescent ionic liquid, which has the characteristics of convenient operation, high sensitivity, short response time, good stability and high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to further illustrate the structure and performance of the product, the following drawings are given.

[0022] Figure 1 The fluorescence quenching of fluorescent ionic liquid containing nonylphenol at different pH values:

[0023] Figure 2 It is the specific detection of nonylphenol by fluorescent ionic liquid when there are multiple pollutants and ions in the water. DETAILED DESCRIPTION

[0024] The raw materials involved in the present invention are all existing products, and the specific preparation operations (such as centrifugation) and testing methods (such as fluorescence detection) are all conventional methods. The technical solution of the present invention is further described below in conjunction with specific implementation methods.

[0025] Preparation Example

[0026]

[0027] Add 20mL of tetrahydrofuran, 3.6g (20mmol) of 1-chloromethylnaphthalene and 1.66g (20mmol) of N-methylimidazole to a 100mL three-necked flask, keep it at 70℃ for 16h in a magnetic heating stirrer, add 15mL of chloroform, shake well to make it a homogeneous phase. Then, remove the tetrahydrofuran and chloroform in the system by rotary evaporation, and use 10mL of tetrahydrofuran for elution. Dry to obtain 1-methyl-3-methylnaphthalene imidazole chloride. Next, weigh 0.8g of sodium hydroxide (20mmol) in a beaker, add 6.7mL of distilled water and shake well to prepare a sodium hydroxide solution with a concentration of 3mol / L as a solvent, and transfer the prepared solution into a single-necked flask for use. Weigh 3.344 g (19.42 mmol) of 1-naphthoic acid and add it to the prepared sodium hydroxide solution (the sodium hydroxide is slightly excessive here to ensure that the reaction proceeds fully, and the specific ratio is: the molar ratio of sodium hydroxide to 1-naphthoic acid is 1.03:1). The system is kept at 30°C in a constant temperature heating magnetic stirrer for 24 hours to obtain a 1-naphthoic acid sodium solution. Finally, 1-methyl-3-methylnaphthoimidazole chloride is added to the 1-naphthoic acid sodium solution, and the system is kept at 60°C in a constant temperature heating magnetic stirrer for 24 hours. After removing the water by rotary evaporation, the product is transferred to a beaker. Add 10 mL of anhydrous ethanol to the solution and shake well, then put the system into a refrigerator and freeze it for 3 hours, filter, rotary evaporate, rinse, and dry to obtain the product 3-methyl-1- Methylimidazole naphthoate, yield 83.2%.

[0028] Nonylphenol detection example in water

[0029] Embodiment 1

[0030] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of aqueous solution containing nonylphenol (nonylphenol concentration was 100 μmol / L), pH was adjusted to 3, and the performance was tested by fluorescence spectrometer. The measured ΔF, i.e., the difference between the measured fluorescence intensity and the fluorescence intensity of the ionic liquid itself, was about 2.5×10 4 .

[0031] Embodiment 2

[0032] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of aqueous solution containing nonylphenol (nonylphenol concentration was 100 μmol / L), pH was adjusted to 4, and the performance was tested by fluorescence spectrometer. The measured ΔF, i.e., the difference between the measured fluorescence intensity and the fluorescence intensity of the ionic liquid itself, was about 1.1×10 5 .

[0033] Embodiment 3

[0034] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of aqueous solution containing nonylphenol (nonylphenol concentration was 100 μmol / L), pH was adjusted to 5, and the performance was tested by fluorescence spectrometer. The measured ΔF, i.e., the difference between the measured fluorescence intensity and the fluorescence intensity of the ionic liquid itself, was about 1.5×10 5 .

[0035] Embodiment 4

[0036] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of aqueous solution containing nonylphenol (nonylphenol concentration was 100 μmol / L), pH was adjusted to 6, and the performance was tested by fluorescence spectrometer. The measured ΔF, i.e., the difference between the measured fluorescence intensity and the fluorescence intensity of the ionic liquid itself, was about 2.3×10 5 .

[0037] Embodiment 5

[0038] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of aqueous solution containing nonylphenol (nonylphenol concentration was 100 μmol / L), pH was adjusted to 7, and the performance was tested by fluorescence spectrometer. The measured ΔF, i.e., the difference between the measured fluorescence intensity and the fluorescence intensity of the ionic liquid itself, was about 2.7×10 5 .

[0039] Embodiment 6

[0040] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of aqueous solution containing nonylphenol (nonylphenol concentration was 100 μmol / L), pH was adjusted to 8, and the performance was tested by fluorescence spectrometer. The measured ΔF, i.e., the difference between the measured fluorescence intensity and the fluorescence intensity of the ionic liquid itself, was about 2.65×10 5 .

[0041] Embodiment 7

[0042] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of aqueous solution containing nonylphenol (nonylphenol concentration was 100 μmol / L), pH was adjusted to 10, and the performance was tested by fluorescence spectrometer. The measured ΔF, i.e., the difference between the measured fluorescence intensity and the fluorescence intensity of the ionic liquid itself, was about 2.7×10 5 .

[0043] Specificity test example

[0044] Embodiment 8

[0045] In 1600 μL Na + In aqueous solution (Na+ 200 μL of fluorescent liquid with a concentration of 10 mmol / L was added to an ionic liquid with a concentration of 200 μmol / L, the pH was adjusted to 7, and the performance was tested using a fluorescence spectrometer. The measured F / F0, that is, the ratio of the measured fluorescence intensity to the fluorescence intensity of the ionic liquid itself, was approximately 1.

[0046] Embodiment 9

[0047] In 1600 μL Mg 2+ In aqueous solution (Mg 2+ 200 μL of fluorescent liquid with a concentration of 10 mmol / L was added to an ionic liquid with a concentration of 200 μmol / L, the pH was adjusted to 7, and the performance was tested using a fluorescence spectrometer. The measured F / F0, that is, the ratio of the measured fluorescence intensity to the fluorescence intensity of the ionic liquid itself, was approximately 1.1.

[0048] Embodiment 10

[0049] In 1600 μL Fe 3+ In aqueous solution (Mg 2+ 200 μL of fluorescent liquid with a concentration of 10 mmol / L was added to an ionic liquid with a concentration of 200 μmol / L, the pH was adjusted to 7, and the performance was tested using a fluorescence spectrometer. The measured F / F0, that is, the ratio of the measured fluorescence intensity to the fluorescence intensity of the ionic liquid itself, was about 0.8.

[0050] Embodiment 11

[0051] In 1600 μL H2PO4 - In aqueous solution (H2PO4 - 200 μL of fluorescent liquid with a concentration of 10 mmol / L was added to the sample, and the pH was adjusted to 7. The performance was tested by fluorescence spectrometer. The measured F / F o That is, the ratio of the measured fluorescence intensity to the fluorescence intensity of the ionic liquid itself is about 0.9.

[0052] Embodiment 12

[0053] In 1600 μL SO4 2- In aqueous solution (SO4 2- 200 μL of fluorescent liquid with a concentration of 10 mmol / L was added to an ionic liquid with a concentration of 200 μmol / L, the pH was adjusted to 7, and the performance was tested using a fluorescence spectrometer. The measured F / F0, that is, the ratio of the measured fluorescence intensity to the fluorescence intensity of the ionic liquid itself, was approximately 1.0.

[0054] Embodiment 13

[0055] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of bisphenol A aqueous solution (bisphenol A concentration was 200 μmol / L), pH was adjusted to 7, and the performance was tested using a fluorescence spectrometer. The measured F / F o That is, the ratio of the measured fluorescence intensity to the fluorescence intensity of the ionic liquid itself is about 0.9.

[0056] Embodiment 14

[0057] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of bisphenol B aqueous solution (bisphenol B concentration was 200 μmol / L), the pH was adjusted to 7, and the performance was tested using a fluorescence spectrometer. The measured F / F0, i.e. the ratio of the measured fluorescence intensity to the fluorescence intensity of the ionic liquid itself, was approximately 0.85.

[0058] Embodiment 15

[0059] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of bisphenol S aqueous solution (bisphenol S concentration was 200 μmol / L), the pH was adjusted to 7, and the performance was tested using a fluorescence spectrometer. The measured F / F0, i.e. the ratio of the measured fluorescence intensity to the fluorescence intensity of the ionic liquid itself, was approximately 1.0.

[0060] Embodiment 16

[0061] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of 1,2-benzenediol aqueous solution (1,2-benzenediol concentration was 200 μmol / L), the pH was adjusted to 7, and the performance was tested using a fluorescence spectrometer. The measured F / F0, i.e. the ratio of the measured fluorescence intensity to the fluorescence intensity of the ionic liquid itself, was approximately 1.0.

[0062] Embodiment 17

[0063] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of an aqueous solution of estrone (the concentration of estrone was 200 μmol / L), the pH was adjusted to 7, and the performance was tested using a fluorescence spectrometer. The measured F / F0, i.e. the ratio of the measured fluorescence intensity to the fluorescence intensity of the ionic liquid itself, was approximately 0.8.

[0064] Embodiment 18

[0065] 200 μL of 10 mmol / L fluorescent liquid was added to 1600 μL of an aqueous solution of nonylphenol (nonylphenol concentration was 200 μmol / L), the pH was adjusted to 7, and the performance was tested using a fluorescence spectrometer. The measured F / F0, i.e. the ratio of the measured fluorescence intensity to the fluorescence intensity of the ionic liquid itself, was approximately 0.3.

[0066] Practical application examples

[0067] Physical water sample testing example

[0068] Embodiment 19

[0069] Take 1600 μL of wok bottom pond water sample, centrifuge and filter it, add nonylphenol (nonylphenol concentration is 5 μmol / L), and then add 200 μL of fluorescent liquid with a concentration of 10 mmol / L, adjust the pH to 7, and perform performance test with fluorescence spectrometer. The nonylphenol content is determined to be 5.1 μmol / L.

[0070] Embodiment 20

[0071] Take 1600 μL of campus water sample, centrifuge and filter it, add nonylphenol (the concentration of nonylphenol is 100 μmol / L), and then add 200 μL of fluorescent liquid with a concentration of 10 mmol / L, adjust the pH to 7, and perform performance test with fluorescence spectrometer. The nonylphenol content is determined to be 100.0 μmol / L.

[0072] Embodiment 21

[0073] Take 1600 μL of tap water sample, centrifuge and filter it, add nonylphenol (nonylphenol concentration is 25 μmol / L), and then add 200 μL of fluorescent liquid with a concentration of 10 mmol / L, adjust the pH to 7, and perform performance test on it with a fluorescence spectrometer. The nonylphenol content is determined to be 25.9 μmol / L.

[0074] Embodiment 22

[0075] Take 1600 μL of Shihu water sample, centrifuge and filter it, add nonylphenol (the concentration of nonylphenol is 100 μmol / L), and then add 200 μL of fluorescent liquid with a concentration of 10 mmol / L, adjust the pH to 7, and perform performance test with fluorescence spectrometer. The nonylphenol content is determined to be 99.2 μmol / L.

[0076] Embodiment 23

[0077] Take 1600 μL of Tayingge water sample, centrifuge and filter it, add nonylphenol (the concentration of nonylphenol is 100 μmol / L), and then add 200 μL of fluorescent liquid with a concentration of 10 mmol / L, adjust the pH to 7, and perform performance test with fluorescence spectrometer. The nonylphenol content is determined to be 101.6 μmol / L.

[0078] Embodiment 23

[0079] Take 1600 μL of Yinshan Lake water sample, centrifuge and filter it, add nonylphenol (the concentration of nonylphenol is 100 μmol / L), and then add 200 μL of fluorescent liquid with a concentration of 10 mmol / L, adjust the pH to 7, and perform performance test with fluorescence spectrometer. The nonylphenol content is determined to be 99.2 μmol / L.

Claims

1. A specific detection method for organic phenol pollutants in water based on fluorescent ionic liquids, characterized in that: The method comprises the following steps: adding ionic liquid into a pretreated aqueous solution containing organic phenol pollutants, and immediately performing fluorescence detection; the ionic liquid is an imidazole salt compound containing a binaphthalene ring structure.

2. The specific detection method of organic phenol pollutants in water based on fluorescent ionic liquids according to claim 1, characterized in that: The structure of ionic liquid compounds is shown below: 。 3. The specific detection method of organic phenol pollutants in water based on fluorescent ionic liquids as claimed in claim 1, characterized in that: The organic phenol is nonylphenol.

4. The specific detection method of organic phenol pollutants in water based on fluorescent ionic liquids as claimed in claim 1, characterized in that: When the water is doped with cations, anions and other phenolic substances, no fluorescence quenching is observed. Only when nonylphenol is doped with the water, fluorescence quenching is observed.

5. The cation as claimed in claim 4 is Ni + 、Na + , Ca 2+ , Fe 3+ , Cu 2+ , K + Mg 2+ 、Co + , Mn 2 ; Anion is COO - 、H2PO4 - 、NO3 - , Cl - 、SO4 2- ; Other phenols include bisphenol A, bisphenol B, bisphenol S, estrone, and 1,2-diphenol.

6. The specific detection method of organic phenol pollutants in water based on fluorescent ionic liquids as claimed in claim 1, characterized in that: The pH of the water environment is 3-10.

7. The specific detection method of organic phenol pollutants in water based on fluorescent ionic liquids as claimed in claim 1, characterized in that The dosage ratio of the fluorescent ionic liquid to the detected water body is 200 μL:1600 μL; the concentration of the fluorescent ionic liquid is 10 mmol / L; and the concentration of nonylphenol is 1-200 μmol / L.

8. The specific detection method of organic phenol pollutants in water based on fluorescent ionic liquids as claimed in claim 1, characterized in that: The water samples were pretreated by centrifugation for 5 min and filtering the supernatant through a 0.45-μm membrane filter.

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