CN111825787A

CN111825787A - Analysis H2Fluorescentized perchloroethylene consisting of solvents of O/DMF mixed solution

Info

Publication number: CN111825787A
Application number: CN202010693150.0A
Authority: CN
Inventors: 徐冬梅; 王晶
Original assignee: Suzhou University
Current assignee: Suzhou University
Priority date: 2020-07-17
Filing date: 2020-07-17
Publication date: 2020-10-27
Anticipated expiration: 2040-07-17
Also published as: CN111825787B

Abstract

The invention relates to a fluorescent perchloroethylene consisting of a solvent for analyzing a mixed solution of water and N, N-dimethylformamide₂The solvent composition of the O/DMF mixed solution can be carried out in a wider pH range, the response speed is high, and the influence of metal ions in the solution is basically avoided.

Description

Analysis H2Fluorescentized perchloroethylene consisting of solvents of O/DMF mixed solution

Technical Field

The invention relates to the field of solvent composition analysis, in particular to a fluorescent perchloroethylene for analyzing the solvent composition of a mixed solution of water and N, N-Dimethylformamide (DMF).

Background

A mixture of water and an organic solvent is a common reaction medium. In some chemical reactions, the mixture of organic solvent and water can affect the reaction process and sometimes even determine the product and yield of the reaction, for example, in the polymer grafting process, the different compositions of the mixture of water and organic solvent are closely related to the position and distribution of the grafted chain and the maximum grafting number. Therefore, it is very important to analyze the composition of the mixed liquid of water and organic solvent. The Karl Fisher method, the electrochemical method, the chromatography method and the like can be used for analyzing the composition of the mixed solution of water and the organic solvent, but the methods have limitations, such as incapability of continuous monitoring, complicated and time-consuming detection process, expensive detection instrument, lack of portability and the like. The fluorescence spectroscopy is superior to other detection technologies due to its simple operation, high sensitivity and wide selection range.

The perchloroethylene (CPVC) is a high polymer material obtained by further chlorinating polyvinyl chloride (PVC), has good flame retardant property, mechanical property, film forming property and corrosion resistance, is rich in source and low in price, and is a high polymer material with economic value and development prospect.

The 1, 8-naphthalimide compound is taken as a typical chromophore and fluorophore, and has good light stability and easily modified structure. When a guest molecule interacts with a group on the 4-position of the guest molecule, signals such as the intensity, wavelength and the like of an absorption spectrum and a fluorescence spectrum are changed, so that derivatives with different spectral properties can be obtained by modifying the 4-position of the guest molecule, and the guest molecule is widely used as a fluorescent probe of a measured object such as metal ions.

CN 110183554A, CN 110256614A discloses a fluorescent perchloroethylene macromolecule and discloses it as Fe³⁺Or Cr³⁺Use of a spectroscopic probe. However, none of the above fluorescent perchloroethylene macromolecules can be used to analyze the solvent composition of a mixture of water and organic solvent. There is currently little satisfactory, simple and practical method to analyze or measure a wide range of H₂The composition of homogeneous mixed liquid of O and organic solvent, therefore, the development of a novel material is needed to solve the above problems.

Disclosure of Invention

In order to solve the above technical problems, the present invention provides a method for analyzing a fluorescing perchloroethylene comprising a solvent of a mixed solution of water and N, N-dimethylformamide, and discloses a perchloroethylene grafted with a 1, 8-naphthalimide group, which can analyze a wide range of H with high accuracy, simplicity and rapidity₂The solvent composition of the O/DMF mixed solution can be in a wide pH range near neutralityThe method is internally carried out, has high response speed and is basically not influenced by metal ions in the solution.

The invention relates to a fluorescing Perchloroethylene (PBNN), the repeating unit of which comprises the following structural formula:

the chlorine content of the fluorescing perchloroethylene is 41-60%. In the present invention, the chlorine content refers to the weight percentage of chlorine atoms in the resin.

Further, the preparation method of the fluorescent perchloroethylene comprises the following steps:

reacting perchloroethylene resin (CPVC) with BNN shown in a formula (1) in an organic solvent at 80-140 ℃ under the action of organic alkali, and obtaining fluorescent perchloroethylene after complete reaction:

further, the molar ratio of the chlorine atom in the perchloroethylene resin to the BNN is 1 (3-8), preferably 1: 5.

Further, the chlorine content of the perchloroethylene resin is 61 to 68%.

Further, the organic base is triethylamine, N-diisopropylethylamine, N-dimethylaminopyridine.

Further, the reaction is carried out under a protective atmosphere, preferably nitrogen.

Further, the organic solvent is one or more selected from N, N-dimethylformamide, ethylene glycol monomethyl ether, 1, 4-dioxane and 1, 2-dichloroethane, preferably 1, 2-dichloroethane.

Further, the reaction time is 6-48 h.

The preparation route of the above fluorescing perchloroethylene is as follows:

further, the preparation method of BNN comprises the following steps:

reacting 4-bromo-1, 8-naphthalic anhydride with N-butylamine in an alcohol solvent at 50 ℃, and obtaining 4-bromo-N-N-butyl-1, 8-naphthalimide (BBN) after complete reaction;

reacting BBN with ethylenediamine at 65 ℃ to obtain BNN after the reaction is completed; the reaction route is as follows:

the invention also claims the application of the fluorescing perchloroethylene in analyzing the solvent composition of the mixed solution of water and N, N-dimethyl formamide; the volume ratio of the water to the N, N-dimethylformamide in the mixed solution of the water and the N, N-dimethylformamide is (1-99) to (1-99).

Further, the pH value of the mixed solution is 5.5-9.5.

Further, the method for analyzing the solvent composition of the mixed solution of water and N, N-dimethylformamide comprises the steps of:

(1) measuring the fluorescence spectrum of the standard solution as an initial spectrum; the standard solution comprises a fluorescent perchloroethylene macromolecule, water and N, N-dimethylformamide, wherein the volume ratio of the water to the N, N-dimethylformamide is (1-99) to (1-99);

(2) measuring the fluorescence spectrum of the solution to be detected as a detection spectrum; the solution to be detected comprises fluorescent perchloroethylene macromolecules, water and N, N-dimethylformamide;

(3) and comparing the detection spectrum with the initial spectrum, and analyzing the contents of water and N, N-dimethylformamide in the solution to be detected.

Furthermore, the concentration of the fluorescing perchloroethylene macromolecules in the standard solution and the solution to be tested is 50 mug/mL.

Further, before the step (2), a step of establishing a standard curve with the volume fraction of water or N, N-dimethylformamide in the standard solution as an abscissa and the fluorescence intensity at 528nm as an ordinate; in the step (3), the fluorescence intensity value at 528nm in the detection spectrum is compared with the standard curve, and the content of water and N, N-dimethylformamide in the solution to be detected is calculated.

Further, two standard curves were established with the volume ratio of water to N, N-dimethylformamide being 85:15 or 80:20, respectively.

Further, in steps (1) and (2), the fluorescence intensities of the standard solution and the test solution reached the maximum within 4 minutes and became stable.

By the scheme, the invention at least has the following advantages:

1. the invention provides a novel fluorescent Perchloroethylene (PBNN), which is prepared by reacting perchloroethylene resin with BNN with fluorescence effect, and the preparation method is simple.

2. The PBNN provided by the invention can relatively accurately, simply and rapidly analyze H with the volume ratio ranging from 1:99 to 99:1₂The composition of the O/DMF mixed solution can be analyzed in a wider pH range near the neutrality, the response speed is high, the influence of metal ions possibly existing in water is basically avoided, and the practicability is better.

3. The PBNN of the invention can be used for simply and effectively analyzing the wide range H₂The solvent composition in the O/DMF mixed solution has a good response rule, and a standard curve can be established to accurately quantify the solvent composition in the solution.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following description is made with reference to the preferred embodiments of the present invention and the accompanying detailed drawings.

Drawings

FIG. 1 shows PBNN at different volume ratios H₂Fluorescence spectrum in O/DMF mixed solution;

FIG. 2 shows the fluorescence intensity of PBNN versus different volume ratios H₂Linear relationship of water content in O/DMF mixture (in terms of H)₂O/DMF ═ 85/15, water content volume ratio from 1% -85% to 85% -99%);

FIG. 3 shows the fluorescence intensity of PBNN versus different volume ratios H₂Linear relationship of water content in O/DMF mixture (in terms of H)₂O/DMF ═ 80/20, water content from 1% -80% to 80% -99%, v/v);

FIG. 4 is a graph of different volume ratios H of metal ion to PBNN analysis₂Composition of O/DMF mixture (H)₂O/DMF＝9/1，H₂O/DMF＝5/5，H₂O/DMF ═ 1/9);

FIG. 5 is a graph of pH versus PBNN analysis for different volume ratios H₂Composition of O/DMF mixture (H)₂O/DMF＝9/1，H₂O/DMF＝5/5，H₂O/DMF ═ 1/9) of fluorescence intensity

FIG. 6 shows PBNN fluorescence analysis of different volume ratios H₂Composition of O/DMF mixture (H)₂O/DMF＝9/1，H₂O/DMF＝5/5，H₂O/DMF ═ 1/9);

FIG. 7 shows BNN at different volume ratios H₂Fluorescence spectra in O/DMF mixtures.

Detailed Description

The following examples are given to further illustrate the embodiments of the present invention. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

In the following examples of the invention, the CPVC used is commercially available and has a chlorine content of about 61-68%.

In the invention, the synthesis method of the intermediate BNN is as follows:

preparing an intermediate BBN by taking 4-bromo-1, 8-naphthalic anhydride and n-butylamine as raw materials: adding 4-bromo-1, 8-naphthalic anhydride into a three-neck flask, stirring and heating to 50 ℃ by taking absolute ethyl alcohol as a solvent, and introducing N₂Under the protection condition, adding n-butylamine, carrying out reflux reaction for 24h, stopping the reaction, cooling to room temperature, pouring into ice water, separating out a light yellow precipitate, filtering, washing a filter cake twice by using deionized water, drying in vacuum, and recrystallizing by using absolute ethyl alcohol to obtain a light yellow needle-shaped solid product, wherein the yield is 74.9%. The melting point is 109.2-110.6 ℃.

Synthesis of intermediate BNN: BBN and anhydrous ethylenediamine are used as raw materials to prepare an intermediate BNN. Taking excessive anhydrous ethylene glycolAmine was placed in a three-necked flask and heated to 65 deg.C, at which time 4-bromo-N-N-butyl-1, 8-naphthalimide (BBN) was added. The resulting mixture was heated to reflux with stirring and reacted for 4 h. After completion of the reaction, the reaction mixture was cooled to room temperature. 10mL of distilled water was poured into the solution, stirred in ice water for 30min, and the formed precipitate was collected by filtration, washed with distilled water and dried in vacuo. And (3) performing column chromatography separation by using dichloromethane and methanol as eluent, removing the solvent by rotary evaporation, and drying in vacuum to obtain orange solid powder BNN with the yield of 74.3%. The melting point of the product is 130.5-131.9 ℃.¹H NMR(400MHz,DMO-d₆)8.70(d,J＝8.3Hz,1H),8.40(d,J＝7.2Hz,1H),8.23(d,J＝8.5Hz,1H),7.72(s,1H),7.65(d,J＝8.4Hz,1H),6.78(d,J＝8.6Hz,1H),3.98(t,J＝7.5Hz,2H),3.40(t,J＝6.4Hz,2H),3.00(s,2H),2.90(t,J＝6.4Hz,2H),1.56(m,2H),1.34(dd,J＝14.9,7.4Hz,2H),0.93(t,J＝7.3Hz,3H).

The first embodiment is as follows: preparation of PBNN

In N₂Under the protection condition, N-dimethylformamide is taken as a solvent, heated and stirred until CPVC is completely dissolved, triethylamine is added, and then the intermediate BNN (the equivalent ratio of chlorine atoms to BNN is N) is added_cl:n_BNN1:5), heating to 140 ℃, reacting for 24h, finishing the reaction, and cooling to room temperature. Separating by column chromatography with dichloromethane and petroleum ether of 10:1 as eluent, removing solvent by rotary evaporation, and vacuum drying to obtain orange yellow solid product with conversion rate of 50.4%.

Example two: preparation of PBNN

In N₂Under the protection condition, ethylene glycol monomethyl ether is used as a solvent, the mixture is heated and stirred until CPVC is completely dissolved, triethylamine is added, and the intermediate BNN (the equivalent ratio of chlorine atoms to BNN is n) is added through stirring_cl:n_BNN1:5), heating to 120 ℃, reacting for 24h, finishing the reaction, and cooling to room temperature. Separating by column chromatography with dichloromethane and petroleum ether of 10:1 as eluent, removing solvent by rotary evaporation, and vacuum drying to obtain orange yellow solid product with conversion rate of 51.3%.

Example three: preparation of PBNN

In N₂Under the protection condition, 1, 4-dioxane is taken as a solvent, the solution is heated and stirred until CPVC is completely dissolved, triethylamine is added, and the intermediate BNN (the equivalent ratio of chlorine atoms to BNN is n) is added through stirring_cl:n_BNN1:5), heating to 100 ℃, reacting for 24h, finishing the reaction, and cooling to room temperature. And (3) performing column chromatography separation by using dichloromethane and petroleum ether as eluent, wherein the solvent is removed by rotary evaporation, and then the product is dried in vacuum to obtain an orange yellow solid product, wherein the conversion rate is 57.3%.

Example four: preparation of PBNN

In N₂Under the protection condition, 1, 2-dichloroethane is used as a solvent, heating and stirring are carried out until CPVC is completely dissolved, triethylamine is added, and then the intermediate BNN (the equivalent ratio of chlorine atoms to BNN is n) is added by stirring_cl:n_BNN1:5), heating to 80 ℃, reacting for 24h, finishing the reaction, and cooling to room temperature. And (3) performing column chromatography separation by using dichloromethane and petroleum ether as eluent, wherein the solvent is removed by rotary evaporation, and then the product is dried in vacuum, so that an orange yellow solid product can be obtained, and the conversion rate is 68.8%.

Example five: preparation of PBNN

In N₂Under the protection condition, 1, 2-dichloroethane is used as a solvent, heating and stirring are carried out until CPVC is completely dissolved, triethylamine is added, and then the intermediate BNN (the equivalent ratio of chlorine atoms to BNN is n) is added by stirring_cl:n_BNN1:5), heating to 80 ℃, reacting for 6h, finishing the reaction, and cooling to room temperature. Separating by column chromatography with dichloromethane and petroleum ether of 10:1 as eluent, removing solvent by rotary evaporation, and vacuum drying to obtain orange yellow solid product with conversion rate of 38.1%.

Example six: preparation of PBNN

In N₂Under the protection condition, 1, 2-dichloroethane is used as a solvent, heating and stirring are carried out until CPVC is completely dissolved, triethylamine is added, and then the intermediate BNN (the equivalent ratio of chlorine atoms to BNN is n) is added by stirring_cl:n_BNN1:5), heating to 80 ℃, reacting for 12h, finishing the reaction, and cooling to room temperature. Separating with column chromatography using dichloromethane and petroleum ether 10:1 as eluent, rotary evaporating to remove solvent, and vacuum drying to obtain orange yellow productThe product was a solid with a conversion of 49.6%.

Example seven: preparation of PBNN

In N₂Under the protection condition, 1, 2-dichloroethane is used as a solvent, heating and stirring are carried out until CPVC is completely dissolved, triethylamine is added, and then the intermediate BNN (the equivalent ratio of chlorine atoms to BNN is n) is added by stirring_cl:n_BNN1:5), heating to 80 ℃, reacting for 36h, finishing the reaction, and cooling to room temperature. And (3) performing column chromatography separation by using dichloromethane and petroleum ether as eluent, wherein the solvent is removed by rotary evaporation, and then the product is dried in vacuum to obtain an orange yellow solid product, wherein the conversion rate is 63.3%.

Example eight: preparation of PBNN

In N₂Under the protection condition, 1, 2-dichloroethane is used as a solvent, heating and stirring are carried out until CPVC is completely dissolved, triethylamine is added, and then the intermediate BNN (the equivalent ratio of chlorine atoms to BNN is n) is added by stirring_cl:n_BNN1:5), heating to 80 ℃, reacting for 48h, finishing the reaction, and cooling to room temperature. Separating by column chromatography with dichloromethane and petroleum ether of 10:1 as eluent, removing solvent by rotary evaporation, and vacuum drying to obtain orange yellow solid product with conversion rate of 61.7%.

In the above examples, the structural characterization data of the prepared PBNN are as follows:

infrared spectrum: IR (v/cm)^-1)v(C-Cl)670.22,v(C-N)1115.43,v(ArH)1387.65,1429.17,1544.57,1596.79,v(C＝O)1635.60,v(C＝N)1681.89,v(CH₃,CH₂)2957.92,2931.53,2870.87, v (NH) 3375.43. Nuclear magnetic hydrogen spectrum:¹H NMR(400MHz，CDCl₃，/ppm)：0.93(NCH₂CH₂CH₂CH₃)，1.25(NCH₂CH₂CH₂CH₃)，1.44(ArNHCH₂CH₂NH)，1.67(NCH₂CH₂CH₂CH₃)，2.87(ArNHCH₂CH₂NH)，2.97(NCH₂CH₂CH₂CH₃)，3.75(ArNHCH₂CH₂NH), 6.64-8.57(ArH), 9.20 (ArNH). Elemental analysis of 0.774% of N, 36.28% of C and 4.82% of H.

Example nine: PBNN Spectrum and H₂Composition relationship of O/DMF mixed solution

Change H₂The volume ratio (v/v) of O to DMF is 1/99,5/95,10/90,15/85,20/80,25/75,30/70,35/65,40/60,45/55,50/50,55/45,60/40,65/35,70/30,75/25,80/20,85/15,90/10,95/5,99/1, and the PBNN is measured at different H₂Ultraviolet-visible absorption spectrum and fluorescence spectrum in mixed solution of O and DMF, PBNN concentration is 50 μ g/mL, fluorescence spectrum excitation wavelength is 433nm, emission wavelength is 528nm, and slit width is 5 nm. As a result, it was found that the UV-visible absorption spectrum was not greatly changed and the fluorescence spectrum was significantly changed as shown in FIG. 1.

FIG. 1a and b show PBNN at different volume ratios H₂Fluorescence spectra and different volume ratios H in O/DMF mixtures₂The fluorescence intensity of the O/DMF mixed solution at 528nm is plotted against the water content in the mixed solution. In FIG. 1a, the curves sequentially correspond to the curves from top to bottom H from the right side to top₂O/DMF ratio. It can be found from fig. 1 that₂The volume ratio of O to DMF is changed, the fluorescence spectrum of the PBNN solution shows obvious regular change, and the fluorescence intensity (F) at 528nm₅₂₈) With the water content (in H) in the mixed liquid₂Volume percent of O V_H2OIndicated) and the magnitude of the decrease gradually decreased and the overall appearance of a smooth curve, as shown in FIG. 1b, the fluorescence spectrum of visible PBNN is seen over a wide range H₂Composition of O/DMF (volume ratio V/V1/99-99/1) mixed solution (by V)_H2OExpress) has a regular response and can be used to analyze a wide range of H₂Composition of O/DMF mixture.

To obtain F₅₂₈And V_H2OThe curve of the relation between the fluorescence intensity and the water content is piecewise and linearly fitted. The first segmentation method is selected as H₂O/DMF ═ 85/15(v/v) as shown in fig. 2. At H₂The O/DMF (v/v) is 1/99-85/15, namely when the water content in the mixed solution is 1-85 percent, the linear equation is as follows: f₅₂₈＝-59850.13546V_H2O+1.75864E7 with correlation coefficient 0.98147 (curve a); at H₂O/DMF (v/v) is 85/15-99/1, namely when the water content in the mixed solution is 85-99 percent, the lineThe equation of property is: f₅₂₈＝-372154.90745V_H2O+4.36466E7 with correlation coefficient 0.97127 (curve b). It can be seen that within two intervals, the fluorescence intensity of the PBNN solution and the water content in the solution have a good linear relationship, and the PBNN solution can be used for quantitatively detecting H₂Composition of O/DMF mixture.

The second segmentation method is selected as H₂O/DMF ═ 80/20(v/v) as shown in fig. 3. In a mixed liquid system H₂The O/DMF (v/v) is 1/99-80/20, namely when the water content in the mixed solution is 1-80%, the linear equation is as follows: f₅₂₈＝-56183.56505V_H2O+1.74881E7 with correlation coefficient 0.98793 (curve a); at H₂The O/DMF (v/v) is 80/20-99/1, namely when the water content in the mixed solution is 80-99 percent, the linear equation is as follows: f₅₂₈＝-314557.74697V_H2O+3.81514E7 with correlation coefficient 0.97356 (curve b). Similar to the first segmentation method, in two intervals, the PBNN solution fluorescence intensity and the water content in the solution have a better linear relation, and the PBNN solution fluorescence intensity and the water content in the solution can be used for quantitatively detecting H₂Composition of O/DMF mixture.

Example ten: metal ion Pair PBNN analysis H₂Effect of O/DMF mixture composition

In practical application, the mixed liquid system containing water may contain various metal ions, and the ions may be used for PBNN H detection₂O/DMF composition was affected, thus H was detected by PBNN₂The metal ion interference resistance of the O/DMF composition is examined. Are respectively at H₂One of 16 metal ions was added to PBNN solution of O/DMF (9/1, 5/5, 1/9, v/v), and the change of fluorescence spectrum of the solution before and after the addition of these ions was compared to examine the anti-interference ability. The concentration of PBNN in the solution was 50. mu.g/mL, and the concentration of each metal ion was 100. mu.M. The excitation wavelength of the fluorescence spectrum is 433nm, the emission wavelength is 528nm, and the slit width is 5 nm. As shown in FIG. 4, the fluorescence intensity of three systems is not greatly changed around 528nm after the addition of the interfering metal ions, so that it can be confirmed that: PBNN in assay H₂When the O/DMF is formed, the anti-interference capability is stronger.

Example eleven: pH vs PBNN analysis H₂Effect of O/DMF mixture composition

In addition, the invention also researches the detection H of PBNN by pH₂Influence of O/DMF composition, determining the utility of PBNN in acid-base environments, as shown in FIG. 5. Respectively adjust H₂The fluorescence spectra of the solutions were measured at different pH values for O/DMF (9/1, 5/5, 1/9, v/v) in PBNN solution at a concentration of 50. mu.g/mL, with an excitation wavelength of 433nm, an emission wavelength of 528nm and a slit width of 5 nm.

As can be seen from FIG. 5, when H is₂pH on PBNN H at 1/9₂The O/DMF composition has little effect; when H is present₂H detection on PBNN at pH > 4.5 when O/DMF is 5/5₂O/DMF composition is not substantially affected; when H is present₂H detection on PBNN at pH between 5.5 and 9.5 with O/DMF 9/1₂The O/DMF composition has less influence. In general, PBNN can detect H over a wide pH range (5.5-9.5) on both sides of neutrality₂O/DMF.

Example twelve: PBNN analysis H₂Speed of composition of O/DMF mixed solution

The PBNN assay H was further investigated₂O/DMF composition rate, concentration of PBNN in solution was 50. mu.g/mL. As shown in fig. 6 for H₂Three systems of O/DMF (9/1, 5/5, 1/9, v/v), PBNN (proton conducting N-terminal N₂The fluorescence intensity of O/DMF composition is gradually increased along with the increase of time t (min), and the fluorescence intensity reaches the maximum value and tends to be stable within 4 minutes, especially H with large water content₂The O/DMF (9/1, v/v) system is said to be a transient response. Visible PBNN can rapidly detect H₂Composition of O/DMF mixture.

Example thirteen: validation PBNN for analysis H₂Practicability of O/DMF mixed liquid composition

Preparation of a catalyst containing H₂In the mixtures containing 1/9 and 9/1 percent of O/DMF (v/v) (i.e., 10 percent and 90 percent of water), PBNN was added to the mixtures to give a PBNN concentration of 50. mu.g/mL, the fluorescence spectra of the solutions were measured and subjected to three parallel experiments to calculate H based on the linear equation obtained by the previous fitting₂The water content in the O/DMF mixture was known as H₂Composition of O/DMF mixed solution。

First according to a first segmentation method (i.e. with H)₂O/DMF ═ 85/15(v/v) bounds) were calculated from the fitted linear equations, and the results are shown in table 1.

For H₂O/DMF (v/v) 1/9 (i.e., 10% water content) in accordance with the linear equation F₅₂₈＝-59850.13546V_H2O+1.75864E7, the water contents of the mixed solutions of the three experiments were found to be 10.96%, 10.97%, 10.95%, respectively, with an average value of 10.96%. Although the relative standard deviation of the three parallel experiments was only 0.09, the measured water content of 10.96% was slightly different from the actual water content of 10%.

For H₂O/DMF (v/v) 9/1 (i.e., 90% water content) in accordance with the linear equation F₅₂₈＝-372154.90745V_H2O+4.36466E7 found that the water content in the mixtures of the three experiments was 90.85%, 90.79%, 90.73%, respectively, with an average value of 90.79%, very close to 90%, and the relative standard deviation of the three replicates was only 0.07. Can be seen as H₂The result of linear fitting with O/DMF (85/15 v/v) as boundary can be used for accurately measuring H with high water content₂And O/DMF mixture.

TABLE 1 PBNN analysis H₂O/DMF mixture (with H)₂O/DMF 85/15(v/v) boundary)

Followed by a second segmentation method (i.e. with H)₂O/DMF ═ 80/20(v/v) bounds) were calculated from the linear equation obtained by fitting, and the results are shown in table 2.

For H₂O/DMF (v/v) 1/9 (i.e., 10% water content) in accordance with the linear equation F₅₂₈＝-56183.56505V_H2O+1.74881E7, the water content in the mixed liquid of the three experiments was found to be 9.93%, 9.94%, 9.92%, respectively, the average value was 9.93%, which was very close to 10%, and the relative standard deviation of the three parallel experiments was found to be 0.10.

For H₂O/DMF (v/v) 9/1 (water content 90%) based onLinear equation F₅₂₈＝-314557.74697V_H2O+3.81514E7 the water content in the mixed liquor of the three experiments was found to be 90.02%, 89.96%, 89.89%, respectively, with an average value of 89.96%, very close to 90%, and the relative standard deviation of the three parallel experiments was found to be 0.07. Can be seen as H₂The result of linear fitting with O/DMF80/20(v/v) as a boundary can be used for accurately measuring H with high water content₂O/DMF mixture, and has low water content₂The error ratio of the O/DMF mixture composition is determined by H₂The error in the analytical determination was reduced considerably by taking O/DMF 85/15(v/v) as a boundary.

TABLE 2 PBNN analysis H₂O/DMF mixture (with H)₂O/DMF80/20(v/v) boundary)

From the results of tables 1-2, it can be seen that both piecewise linear fit results can be used to analyze H₂The solvent composition in the O/DMF mixed solution has better practicability.

Comparative example

Analysis H for comparison of BNN with PBNN₂Performance of solvent composition in O/DMF mixture by BNN analysis of H₂The composition of the solvent in the O/DMF mixed solution is as follows:

preparing different proportions of H₂BNN was added to each O/DMF (v/v) mixture so that the concentration of BNN in the resulting mixture was 10. mu.M (the concentration commonly used for small molecule indicators), and the fluorescence spectra of the solutions were measured, and the results are shown in FIGS. 7a and b. FIGS. 7a and b are the BNN at different volume ratios H₂Fluorescence spectra and different volume ratios H in O/DMF mixtures₂The fluorescence intensity of the O/DMF mixed solution at 524nm is plotted against the water content in the mixed solution. In FIG. 7a, H₂O/DMF 35/65 at H₂The curve of the dotted line sequentially corresponds to H from bottom to top on the right side of the graph from bottom to top in the range of O/DMF 1/99-35/65₂The ratio of O/DMF; at H₂The curve of the solid line corresponds to H from the top to the bottom on the right side of the figure in sequence in the range of O/DMF 35/65-99/1₂Ratio of O/DMF. As can be seen in FIG. 7b, the fluorescence intensity of BNN solution at 524nm is dependent on H₂Volume ratio of O to DMF (in H)₂Volume percent of O V_H2OExpressed) shows a curve-increasing curve-decreasing curve-increasing curve-decreasing curve-increasing curve-decreasing₅₂₄) For two water content cases, therefore, a fluorescence value measured for a solution of unknown solvent content, which may correspond to a different solvent content, does not allow accurate knowledge of the solvent composition. And in most of H₂Fluorescence intensity of BNN (F) in the range of O/DMF composition₅₂₄) There is not a simple linear relationship with the water content in the mixture, and it can be seen that BNN cannot be used to analyze a wide range of H₂Composition of O/DMF mixture.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, it should be noted that, for those skilled in the art, many modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims

1. A fluorescing perchloroethylene, which comprises the following structural formula in its repeating unit:

the chlorine content of the fluorescent perchloroethylene is 41-60%.

2. Fluorescently chlorinated perchloroethylene according to claim 1, characterized in that it is prepared by a process comprising the following steps:

reacting perchloroethylene resin with BNN shown in a formula (1) in an organic solvent at 80-140 ℃ under the action of organic alkali, and obtaining the fluorescent perchloroethylene after the reaction is completed:

3. the fluorescing perchloroethylene of claim 2, wherein the molar ratio of chlorine atoms in the perchloroethylene resin to BNN is 1 (3-8).

4. The fluorescing perchloroethylene of claim 2, wherein the perchloroethylene resin has a chlorine content of 61 to 68 percent.

5. Use of the fluorescing perchloroethylene of any of claims 1 to 4 for analyzing the solvent composition of a mixed solution of water and N, N-dimethylformamide; the volume ratio of the water to the N, N-dimethylformamide in the mixed solution of the water and the N, N-dimethylformamide is (1-99) to (1-99).

6. Use according to claim 5, characterized in that: the pH value of the mixed solution is 5.5-9.5.

7. The use according to claim 5, wherein the method for analyzing the solvent composition of the mixed solution of water and N, N-dimethylformamide comprises the steps of:

(1) measuring the fluorescence spectrum of the standard solution as an initial spectrum; the standard solution comprises the fluorescent perchloroethylene macromolecules, water and N, N-dimethylformamide, wherein the volume ratio of the water to the N, N-dimethylformamide is (1-99) to (1-99);

(2) measuring the fluorescence spectrum of the solution to be detected as a detection spectrum; the solution to be detected comprises the fluorescence perchloroethylene macromolecules, water and N, N-dimethylformamide;

8. Use according to claim 5, characterized in that: in the standard solution and the solution to be detected, the concentration of the fluorescing perchloroethylene macromolecules is 50 mu g/mL.

9. Use according to claim 5, characterized in that: before the step (2), a step of establishing a standard curve by taking the volume fraction of water or N, N-dimethylformamide in the standard solution as an abscissa and the fluorescence intensity at 528nm as an ordinate; in the step (3), the fluorescence intensity value at 528nm in the detection spectrum is compared with a standard curve, and the content of water and N, N-dimethylformamide in the solution to be detected is calculated.

10. Use according to claim 9, characterized in that: two standard curves are respectively established by taking the volume ratio of water to N, N-dimethylformamide as a boundary of 85:15 or 80: 20.