阅读说明：本技术 一种荧光离子液体及其合成方法与应用 (Fluorescent ionic liquid and synthesis method and application thereof ) 是由 车思莹 尹琳琳 佘远斌 范尧 于 2021-07-23 设计创作，主要内容包括：本发明公开了一种式(I)所示的荧光离子液体[HDQ][P-(66614)],并提供了一种快速、可视化检测实际样品中汞离子及对常见金属离子进行区分的方法；本发明以离子交换法合成具有蓝色荧光发射的离子液体,该方法合成步骤简单、合成产率高；合成的荧光离子液体热稳定性好、不易挥发、对环境污染性小；离子液体对汞离子有较强的特异性、灵敏度,可实现较宽线性范围内汞离子的检测；本发明可以对实际样品中的汞离子进行定性分析、定量检测,为复杂体系中汞离子的检测提供了可能；(The invention discloses a fluorescent ionic liquid (HDQ) shown in formula (I)][P 66614 ]And provides a method for rapidly and visually detecting mercury ions in an actual sample and distinguishing common metal ions; the ionic liquid with blue fluorescence emission is synthesized by an ion exchange method, and the method has simple synthesis steps and high synthesis yield; the synthesized fluorescent ionic liquid has good thermal stability, is not easy to volatilize and has small pollution to the environment; the ionic liquid has strong effect on mercury ionsThe detection of mercury ions in a wider linear range can be realized due to the anisotropy and the sensitivity; the invention can carry out qualitative analysis and quantitative detection on the mercury ions in the actual sample, and provides possibility for the detection of the mercury ions in a complex system;)

1. A fluorescent ionic liquid with chemical formula of [ HDQ][P₆₆₆₁₄]The structural formula is shown as the formula (I):

2. the fluorescent ionic liquid [ HDQ ] of claim 1][P₆₆₆₁₄]The synthesis method is characterized by comprising the following steps:

using absolute ethyl alcohol as solvent to react with [ P ]₆₆₆₁₄][OH]Stirring and reacting with 8-hydroxyquinoline at 40-80 ℃ for 2-24 h, then removing the solvent by rotary evaporation, and drying in a nitrogen atmosphere at 40-80 ℃ to obtain the fluorescent ionic liquid (HDQ)][P₆₆₆₁₄]；

Said [ P ]₆₆₆₁₄][OH]The molar ratio of the 8-hydroxyquinoline to the compound is 1: 1.

3. the synthetic method of claim 2 wherein [ P ] is₆₆₆₁₄][OH]From [ P ]₆₆₆₁₄][Cl]Dechlorinating with strong basic anion exchange resinThe dechlorination treatment method comprises the following steps:

will [ P ]₆₆₆₁₄][Cl]Adding the ethanol solution into a chromatographic column filled with strongly basic anion exchange resin, and collecting the effluent to obtain [ P ]₆₆₆₁₄][OH]The ethanol solution of (1).

4. The fluorescent ionic liquid [ HDQ ] of claim 1][P₆₆₆₁₄]The fluorescent probe can be used as a fluorescent/colorimetric probe for rapid detection of mercury ions in practical samples.

5. The use of claim 4, wherein the method of detection is as follows:

(1) drawing a standard fitting curve

Fluorescent ionic liquid (HDQ)][P₆₆₆₁₄]Dissolving in anhydrous alcohol, adding standard mercuric sulfate, preparing standard solutions with different mercuric sulfate concentrations, and recording under the conditions of excitation wavelength of 320nm and excitation and emission slit widths of 10nm and 20nm respectively [ HDQ ]][P₆₆₆₁₄]Fitting a linear curve by taking the fluorescence intensity of the highest peak as a vertical coordinate and the mercury sulfate concentration as a horizontal coordinate;

(2) actual sample detection

Fluorescent ionic liquid (HDQ)][P₆₆₆₁₄]Dissolved in absolute ethanol and diluted to a concentration at an excitation wavelength of 320nm, [ HDQ ]][P₆₆₆₁₄]And (2) the fluorescence intensity at 414nm is 800-1300 a.u., adding a sample to be detected, collecting fluorescence emission spectra under the conditions that the excitation wavelength is 320nm and the excitation and emission slit widths are 10nm and 20nm respectively, and carrying out quantitative analysis on the concentration of mercury ions in the actual sample according to the linear curve fitted in the step (1).

Technical Field

The invention relates to a fluorescent ionic liquid, a synthesis method thereof and application thereof in mercury ion fluorescence/colorimetric rapid detection and common metal ion differentiation in practical samples.

Background

Among all heavy metal ions, mercury is one of the useful metal elements that are ubiquitous in the industries of cosmetics, paints, batteries, ammunition factories, and the like, against rule. Many untreated fumes, waste water and waste are discharged into the ecological environment, which causes a wide distribution of mercury in the air, water and soil, in the form: metallic mercury, inorganic mercury, mercury ions, and organic mercury. And mercury ions are among the most important of the strongly toxic analytes. When mercury ions enter a human body through contact or a food chain, the mercury ions are combined with substances containing sulfydryl, such as enzyme and protein, so that the functions and growth of cells are influenced. The current detection methods for mercury ions mainly comprise an electrochemical analysis method, an inductively coupled plasma mass spectrometry method, a high performance liquid chromatography method, an atomic absorption spectrometry method and the like, and the methods have low detection limit and high sensitivity, but the instrument is expensive and the pretreatment is complex, so that the establishment of a detection method capable of quickly, accurately and sensitively detecting mercury ions is of great importance to the safety of human beings and the environment.

As a functional material, ionic liquids have been successfully used in various fields such as catalysts, synthesis, electrochemistry, and extraction. Has been widely used in the fields of gas capture, solvent, catalyst, extraction and the like, and achieves good effects. More importantly, in recent years, ionic liquids have shown great potential as fluorescent probes for detecting target objects, particularly metal ions, due to their high degree of tunability. The ionic liquid has the advantages of stable structure, excellent thermal stability, good biocompatibility, high adjustability and great development potential.

Aiming at solving the problem of high cost of mercury ion detection in practical samplesLong time, complicated pretreatment and the like, and the invention uses simple acid-base deprotonation reaction to generate [ P₆₆₆₁₄][Cl]The ionic liquid [ HDQ ] with blue fluorescence emission is synthesized with 8-hydroxyquinoline as a raw material][P₆₆₆₁₄]A fluorescence quenching type fluorescence/colorimetric sensor is developed for detecting mercury ions in an actual sample, and the possibility is provided for the rapid and accurate detection of the mercury ions in a complex system.

Disclosure of Invention

The invention designs and synthesizes a novel high-sensitivity and specific ionic liquid type fluorescent probe, the probe can be used for quickly detecting mercury ions in an actual sample, the differentiation of common metal ions can be realized by combining chemometrics, and the method has the advantages of low detection limit on the mercury ions, high sensitivity, wide linear range and simple operation.

The invention uses fluorescent ionic liquid (HDQ)][P₆₆₆₁₄]Is a fluorescent/colorimetric probe, takes mercury ions as a substance to be detected, and passes the mercury ions and [ HDQ ]][P₆₆₆₁₄]The specific combination quenches the fluorescence of the probe, and the quantitative analysis is carried out according to a linear curve which is fitted by taking the fluorescence intensity as a vertical coordinate and the concentration of the mercury sulfate as a horizontal coordinate, so that the accurate identification and quantitative detection of mercury ions in an actual sample are realized. Combining 1-10 PSO-OSWLS-SVM model pairs⁴Mercury ions in nM concentration range are analyzed more accurately and then the differentiation of common metal ions is realized by combining with PLSDA model.

The technical scheme of the invention is as follows:

a fluorescent ionic liquid with chemical formula of [ HDQ][P₆₆₆₁₄]The structural formula is shown as the formula (I):

the fluorescent ionic liquid [ HDQ ] of the invention][P₆₆₆₁₄]The synthesis method comprises the following steps:

using absolute ethyl alcohol as solvent to react with [ P ]₆₆₆₁₄][OH]Stirring and reacting with 8-hydroxyquinoline at 40-80 ℃ for 2-24 h, then removing the solvent by rotary evaporation, and drying in a nitrogen atmosphere at 40-80 DEG CObtaining fluorescent ionic liquid (HDQ)][P₆₆₆₁₄]；

Said [ P ]₆₆₆₁₄][OH]The molar ratio of the 8-hydroxyquinoline to the compound is 1: 1;

said [ P ]₆₆₆₁₄][OH]From trihexyl (tetradecyl) phosphonium chloride ([ P ]₆₆₆₁₄][Cl]) The dechlorination treatment agent is obtained by dechlorination treatment of strong-base anion exchange resin, and the specific dechlorination treatment method comprises the following steps:

will [ P ]₆₆₆₁₄][Cl]Adding the ethanol solution into a chromatographic column filled with strongly basic anion exchange resin, and collecting the effluent to obtain [ P ]₆₆₆₁₄][OH]The ethanol solution (without evaporation, directly used for reaction).

The fluorescent ionic liquid [ HDQ ] of the invention][P₆₆₆₁₄]The method can be used as a fluorescence/colorimetric probe for rapid detection of mercury ions in an actual sample, and the specific detection method comprises the following steps:

(1) drawing a standard fitting curve

Fluorescent ionic liquid (HDQ)][P₆₆₆₁₄]Dissolving in anhydrous alcohol, adding standard mercuric sulfate, preparing standard solutions with different mercuric sulfate concentrations, and recording under the conditions of excitation wavelength of 320nm and excitation and emission slit widths of 10nm and 20nm respectively [ HDQ ]][P₆₆₆₁₄]Fitting a linear curve by taking the fluorescence intensity of the highest peak as a vertical coordinate and the mercury sulfate concentration as a horizontal coordinate;

(2) actual sample detection

Fluorescent ionic liquid (HDQ)][P₆₆₆₁₄]Dissolved in absolute ethanol and diluted to a concentration at an excitation wavelength of 320nm, [ HDQ ]][P₆₆₆₁₄]And (2) the fluorescence intensity at 414nm is 800-1300 a.u., adding a sample to be detected, collecting fluorescence emission spectra under the conditions that the excitation wavelength is 320nm and the excitation and emission slit widths are 10nm and 20nm respectively, and carrying out quantitative analysis on the concentration of mercury ions in the actual sample according to the linear curve fitted in the step (1).

The fluorescence spectrum measurement conditions of the invention are that the excitation wavelength is 320nm, the widths of the excitation slit and the emission slit are respectively 10nm and 20nm, and the measurement range of the emission wavelength is 340-580 nm.

The method carries out quantitative analysis on the mercury ions in the actual sample according to a linear curve which is fitted by taking the fluorescence intensity as a vertical coordinate and the mercury sulfate concentration as a horizontal coordinate.

The method combines an optimized sample weighted least square support vector machine pair 1-10 based on a particle swarm optimization (PSO-OSWLS-SVM) model⁴Linear fitting was performed with nM mercury sulfate, followed by a partial least squares analysis (PLSDA) model to achieve differentiation of common metal salts.

[ HDQ ] prepared by the invention][P₆₆₆₁₄]The fluorescent/colorimetric probe can be used for detecting mercury ions in tea, white spirit, urine, human plasma, human serum and bovine serum albumin.

The invention uses fluorescent ionic liquid (HDQ)][P₆₆₆₁₄]Is a fluorescent/colorimetric probe, takes mercury ions as a substance to be detected, and passes the mercury ions and [ HDQ ]][P₆₆₆₁₄]The specific binding quenches the fluorescence of the probe, and the accurate identification and quantitative detection of mercury ions in the actual sample are realized by utilizing a linear curve which is fitted by taking the fluorescence intensity as a vertical coordinate and the mercury sulfate concentration as a horizontal coordinate to carry out quantitative analysis. And a PSO-OSWLS-SVM model is combined to perform more accurate quantitative analysis, and a PLSDA model is combined to distinguish common metal salts.

Compared with the prior art, the invention has the beneficial effects that:

the invention develops a novel fluorescent ionic liquid and provides a method for quickly and visually detecting mercury ions in an actual sample and distinguishing common metal ions. To prepare an ionic liquid having blue fluorescence emission [ HDQ ]][P₆₆₆₁₄]And (3) as a fluorescence/colorimetric probe, preparing an ethanol solution with a fixed concentration, adding the actual sample to be detected, and uniformly mixing. Recording the excitation wavelength at 320nm [ HDQ ]][P₆₆₆₁₄]The quantitative detection of the mercury ions in the actual sample is realized according to the fitted linear curve by the fluorescence excitation spectrum, and then the common metal ions are distinguished by combining the chemometrics.

The ionic liquid with blue fluorescence emission is synthesized by an ion exchange method, and the method has simple synthesis steps and high synthesis yield; synthetic [ HDQ][P₆₆₆₁₄]The fluorescent ionic liquid has good thermal stability,The volatile is not easy, and the pollution to the environment is small; ionic liquids [ HDQ][P₆₆₆₁₄]The method has stronger specificity and sensitivity to mercury ions, and can realize the detection of the mercury ions in a wider linear range; the invention can carry out qualitative analysis and quantitative detection on the mercury ions in the actual sample, and provides possibility for the detection of the mercury ions in a complex system.

Drawings

FIG. 1 shows the present invention in [ HDQ ]][P₆₆₆₁₄]The fluorescence emission spectra of the ethanol solutions to which mercury sulfate was added at different concentrations (1nM, 5nM, 30nM, 70nM, 0.1. mu.M, 0.3. mu.M, 0.5. mu.M, 0.7. mu.M, 1. mu.M, 3. mu.M, 5. mu.M, 7. mu.M, 10. mu.M).

FIG. 2 shows the present invention in [ HDQ ]][P₆₆₆₁₄]The visual photographs taken under the irradiation of an ultraviolet lamp were obtained by adding ethanol solutions of mercury sulfate at different concentrations (0, 0.1nM, 1nM, 30. mu.M, 70. mu.M, 1. mu.M, 10. mu.M) to the ethanol solution of (A).

FIG. 3 shows [ HDQ ] according to the present invention][P₆₆₆₁₄]The fluorescence intensity of the fluorescent material is a vertical coordinate, and the concentration (9-100 nM) of mercury sulfate is a linear curve (A) fitted by a horizontal coordinate; with [ HDQ ]][P₆₆₆₁₄]The fluorescence intensity of (A) is shown as the ordinate, and the concentration of mercury sulfate (0.3-1 μ M) is shown as the linear curve (B) fitted on the abscissa.

FIG. 4 shows the predicted error values of the test set over 100 PSO cycles; illustration is shown: predicting root mean square error values (A) of the test set predicted in 100 PSO cycles; quantitative results (B) of mercury ions using PSO-OSWLS-SVM.

FIG. 5 shows the present invention in [ HDQ ]][P₆₆₆₁₄]Adding an ethanol solution (70 μ M) of mercuric sulfate and other common metal salts (lambda)_rawem-λ_em) Plot of the ratio of fluorescence intensity.

FIG. 6 shows the result of discrimination and discrimination of common metal ions by PLSDA according to the present invention.

FIG. 7 the results of the present invention in the actual samples (white spirit, tea, human plasma, human serum, bovine serum albumin, urine) are recovered with the addition of standards.

Detailed Description

In order to better understand the present invention, the following embodiments are further illustrated, but the present invention is not limited to the following embodiments, and the following should not be construed as limiting the scope of the present invention.

The chemicals and solvents used in the examples were all analytical grade.

The strongly basic anion exchange resin used was a 717 strongly basic type I anion exchange resin available from Aladdin Chemicals, Inc.

The fluorescence spectrum measurement conditions are that the excitation wavelength is 320nm, the emission wavelength is 340-580 nm, and the widths of the excitation slit and the emission slit are 10nm and 20nm respectively.

Example 1

The synthesis method of the fluorescent ionic liquid comprises the following specific steps:

(1)[P₆₆₆₁₄][Cl]dechlorination treatment:

will [ P ]₆₆₆₁₄][Cl]The ethanol solution of (a) is slowly added to a chromatographic column containing strongly basic anion exchange resin ([ P ]₆₆₆₁₄][Cl]The mass ratio of the anion exchange resin to the strongly basic anion exchange resin is 1: 6) collecting the effluent to obtain [ P ]₆₆₆₁₄][OH]The ethanol solution of (1).

(2) Fluorescent ionic liquid (HDQ)][P₆₆₆₁₄]The synthesis of (2):

0.1405g of 8-hydroxyquinoline and [ P ] obtained in step (1)₆₆₆₁₄][OH]Ethanol solution (containing [ P ]₆₆₆₁₄][OH]5.1847g) was charged into a 250mL round bottom flask, 50mL of anhydrous ethanol was added, and the reaction was carried out for 12 hours under stirring in an oil bath at 60 ℃ [ P ]₆₆₆₁₄][OH]The molar ratio to 8-hydroxyquinoline is 1: 1. And removing the solvent ethanol from the reacted product by using a rotary evaporator, and heating the product in a nitrogen atmosphere to remove trace ethanol and water in the product to finally obtain brown viscous liquid. And (5) sealing and storing at room temperature. The reaction formula is as follows:

example 2

The ionic liquid is used as a colorimetric/fluorescent probe for quickly detecting mercury ions in an actual sample, and the method specifically comprises the following steps:

(1) detection of mercury ions by fluorescent/colorimetric probes:

0.0314g of [ HDQ ] is weighed][P₆₆₆₁₄]Dissolving in solvent absolute ethyl alcohol, and preparing into 1mM stock solution. 100 μ L of [ HDQ ]][P₆₆₆₁₄]The stock solution of (2) was mixed with 800. mu.L of an absolute ethanol solution, 100. mu.L of mercury ion solutions of different concentrations (1nM, 5nM, 30nM, 70nM, 0.1. mu.M, 0.3. mu.M, 0.5. mu.M, 0.7. mu.M, 1. mu.M, 3. mu.M, 5. mu.M, 7. mu.M, 10. mu.M) were added thereto, and fluorescence emission spectra were collected under conditions of an excitation wavelength of 320nM and excitation and emission slit widths of 10nM and 20nM, respectively, as shown in FIG. 1.

It can be seen from FIG. 1 that the fluorescence intensity of the fluorescent probe gradually increases as the concentration of mercury ions gradually increases from 1nM to 100 nM; when the concentration of mercury ions gradually increased from 300nM to 10⁴At nM, the fluorescence intensity of the fluorescent probe gradually decreases and produces a blue shift.

(2) A visualization of the solution was taken in several cuvettes with exactly 100. mu.L of stock solution and with different concentrations (0, 0.1nM, 1nM, 30. mu.M, 70. mu.M, 1. mu.M, 10. mu.M) of mercuric sulfate in ethanol under 365nM wavelength illumination, as shown in FIG. 2.

(3) Drawing of standard curve

The results of quantitative analysis using a linear curve fitted with the fluorescence intensity as ordinate and the mercury sulfate concentration as abscissa are shown in fig. 3A and 3B. When the concentration of mercury ions is 1-100 nM, the equation obtained by linear fitting is 0.73x +690.84 (R)²0.991); when the concentration of mercury ions is 300-10⁴In nM, the equation obtained by linear fitting is-35.13 x +1046.26 (R)²＝0.991)。

(4) Quantification of mercury ions using PSO-OSWLS-SVM

The full spectrum data is analyzed by combining a PSO-OSWLS-SVM model, and 1 x 10 can be realized^-5Accurate quantitative detection of mercury ions in nM wide linear range, PSO cycle optimization results are shown in FIG. 4A, and quantitative results are shown in FIG. 4B.

(5) Common metal ion and anion pairs [ HDQ][P₆₆₆₁₄]Interference in detection of mercury ions

mu.L of stock solution was mixed with 70. mu.L of 10. mu.M mercuric sulfate in ethanol or 100. mu.L of 10. mu.M other metal salt (AgNO)₃，Zn(Ac)₂，MgCl₂，KCl，BaCl₂，NiCl₂，ZnCl₂，Pb(NO₃)₂，CdCl₂，Ni(NO₃)₂，Zn(NO₃)₂，CaCl₂，Co(NO₃)₃，ZnSO₄，Cu(NO₃)₂，CuSO₄，MnCl₂，Al(NO₃)₃，CuCl₂，Mn(Ac)₄，FeCl₂，FeSO₄，Fe(NO₃)₃，FeCl₃，Cr(NO₃)₃NaCl) was mixed with an ethanol solution, the volume was fixed to 1mL using anhydrous ethanol, and fluorescence emission spectra were collected under conditions that the excitation wavelength was 320nm and the excitation and emission slit widths were 10nm and 20nm, respectively. With addition of solutions of different metal salts in ethanol (lambda)_rawem-λ_em) The ratio of the fluorescence intensity to the intensity of the fluorescence is plotted on the ordinate, and the kind of the metal salt is plotted on the abscissa in a bar chart, as shown in FIG. 5.

(6) Differentiation of common metal ions using PLSDA

(ii) to collect [ HDQ ]][P₆₆₆₁₄]And processing full spectrum data after reaction with metal ions with different concentrations by using a PLSDA model. In the model, each metal ion is represented by f₁-f₂₆Carry out marking (f)₁-f₂₆Are each HgSO₄,NaCl,KCl,AgNO₃,Ni(NO₃)₂,NiCl₂,MgCl₂,ZnCl₂,Zn(NO₃)₂,Zn(Ac)₂,ZnSO₄,CaCl₂,CuCl₂,Cu(NO₃)₂,CuSO₄,BaCl₂,CdCl₂,Pb(NO₃)₂,FeCl₂,FeSO₄,MnCl₂,Al(NO₃)₃,FeCl₃,Fe(NO₃)₃,Mn(Ac)₄,Cr(NO₃)₃)，HgSO₄The sample includes 140 samples, and the other metal ions are all 90 samples. All metal ion samples from each set of samples were randomly drawn and reassigned to the training setAnd prediction convergence. The results are shown in fig. 6, and the common metal ions can be distinguished by processing full spectrum data in combination with the PLSDA model.

(7) Detection of mercury ions in a real sample

Soaking 0.05g of tea in 5mL of ethanol for 10min, and collecting supernatant. Adding a certain amount of ethanol solution of mercury sulfate as a solution to be detected, adding 100 μ L of stock solution into the solution to be detected, and collecting fluorescence emission spectra under the conditions that the excitation wavelength is 320nm and the excitation and emission slit widths are 10nm and 20nm respectively.

Similarly, a certain amount of mercuric sulfate was added to white spirit, urine, human serum (0.01g dissolved in 10mL of absolute ethanol), human plasma (100. mu.L dissolved in 9.9mL of absolute ethanol), bovine serum albumin (0.01g dissolved in 10mL of absolute ethanol) as a test solution, and the actual samples were analyzed for mercury ions by the standard recovery method, and the results are shown in FIG. 7.