CN103674912B - The fluorescence detection method of quaternized pyridinium cationic surfactants and application thereof - Google Patents

Abstract

Fluorescence detection method and application of pyridinium quaternary ammonium salt cationic surfactant. The invention relates to a fluorescence detection agent for a pyridine quaternary ammonium salt cationic surfactant and an application method thereof. The invention provides a fluorescent detection agent for detecting a pyridinium quaternary ammonium salt cationic surfactant with wide linear range, low detection limit, low cost and fast and an application method thereof. The structural formula of pyridinium quaternary ammonium salt cationic surfactant is R=C _n H _2n+1 , or C _n H _2n+1 NCOCH ₂ , n=8-18; X ^- =Cl ^- , Br ^- , I ^- . It can be applied to the detection of pyridinium quaternary ammonium salt cationic surfactants in actual environmental water samples, such as surface water, lake water and urban sewage.

Description

Fluorescence detection method and application of pyridinium quaternary ammonium salt cationic surfactant

technical field

The invention relates to a fluorescence detection method and application of a pyridinium quaternary ammonium salt cationic surfactant.

Background technique

Quaternary ammonium salt-type cationic surfactants are cationic surfactants with high output and wide application. Among them, the typical and most common type is pyridinium quaternary ammonium salt cationic surfactant, the molecule of alkyl pyridinium quaternary ammonium salt (RPB) The structural formula is as follows:

R=C _n H _2n+1 , or C _n H _2n+1 NCOCH ₂ , n=8-18; X ^- =Cl ^- , Br ^- , I ^- ; because of its good water solubility, it is both acid and alkali resistant and has Strong bactericidal effect, widely used in industrial production and daily products, will eventually be released into the environment, causing environmental problems. Therefore, establishing a new detection method for pyridinium quaternary ammonium salt cationic surfactant has special significance for biology, chemistry, environment and medicine.

Diao et al. synthesized a cadmium telluride colloidal fluorescent molecular probe for a series of cationic surfactants such as hexadecyltrimethylammonium bromide, dodecyltrimethylammonium bromide and chloride in aqueous solution. The detection limit was 5.0×10 ^-8 mol/L, and the linear range was 2.0×10 ^-7 ～7.0×10 ^-6 mol/L. (Diao, XL; Xia, YS; Zhang, TLAnal. Bioanal. Chem. 2007, 388, 1191–1197).

In addition, detection methods such as ion selective electrode method, high performance liquid chromatography, flow injection analysis, capillary electrophoresis and chromatography-mass spectrometry can also be applied to the detection of cationic surfactants.

However, although the existing methods can detect cationic surfactants or anionic surfactants in aqueous solution, the detection methods lack single selectivity, narrow detection linear range, high detection limit, high cost, long time consumption, and difficult operation. Disadvantages include tediousness, lack of reproducibility, and signal stability. Therefore, it is necessary to continuously research and develop a detection method with simple method, low cost, high sensitivity, short response time and single selective recognition of pyridinium quaternary ammonium salt cationic surfactant.

Contents of the invention

The invention provides a method for fluorescence detection of pyridinium quaternary ammonium salt cationic surfactant with wide detection linear range, low detection limit, low cost and fast and application thereof.

The fluorescence detection method of pyridinium quaternary ammonium salt cationic surfactant is characterized in that the structural formula of pyridinium quaternary ammonium salt cationic surfactant is

R=C _n H _2n+1 , or C _n H _2n+1 NCOCH ₂ , n=8-18; X ^- =Cl ^- , Br ^- , I ^- .

The invention also provides the application of the fluorescence detection to the pyridinium quaternary ammonium salt cationic surfactant.

The method of the present invention utilizes fluorescence spectrum, with fluorescent dye CXT (4,4'-bis-(4-hydroxyethylamino-anilino-1,3,5-triazine-2 base)amino-stilbene-2 , 2'-disulfonic acid sodium salt) as a fluorescent molecular probe, with Brij35 micellar aqueous solution as the medium, Tris-HCl or Hepes as the buffer solution, from common cationic surfactants, anionic surfactants and nonionic surfactants Single selective detection of pyridinium quaternary ammonium cationic surfactants in solvents.

The method of the present invention has the following advantages:

1. The present invention uses fluorescent dye CXT as a detection reagent, which can single-selectively detect pyridinium quaternary ammonium salt cationic surfactants. Fluorescent dye CXT is an excellent whitening agent with wide sources and low price. It is a special dye that can emit blue-violet fluorescence. It has the advantages of good spectral performance, high solubility and low pollution.

2. The present invention uses Tris-HCl or Hepes as a buffer solution, and uses Brij35 micellar aqueous solution as a medium, so that the solubility of CXT and pyridinium quaternary ammonium salt cationic surfactant in aqueous solution is better, and the low concentration below the millimolar concentration Concentration pyridinium quaternary ammonium cationic surfactant and CXT can form a stable complex, which can quench the fluorescence of CXT.

3. The method of the present invention is not affected by other common surfactants and inorganic salts, such as cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), lauryl Sodium sulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), sodium p-toluenesulfonate (SPTS), OP–3～30, TritonX–100, Tween–20, Tween–40, Tween–60, Tween–80, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^3- , NO ^3- , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2– , SO ₄ ^2- plasma effect with high selectivity.

4. The present invention not only avoids the cumbersome organic synthesis problem in the current research on fluorescent molecular probes of pyridinium quaternary ammonium salt cationic surfactants, but also has incomparable safety for synthetic probes.

5. The present invention provides a method for testing pyridine with simple operation, fast response time (2min), high selectivity, high sensitivity and low detection limit (8.2×10 ^-9 mol/L～7.6×10 ^-8 mol/L) Method for quaternary ammonium cationic surfactants.

6. The present invention can be applied to the detection of pyridinium quaternary ammonium salt cationic surfactants in actual environmental water samples, such as surface water, lake water and sewage.

Description of drawings

Figure 1 is a graph showing the variation of CXT fluorescence intensity with different surfactants in Test 1 (1);

Figure 2 is a graph showing the variation of fluorescence intensity with pH value in Test 1 (2); where a is CXT, and b is CXT/CPB;

Figure 3 is a graph showing the change in fluorescence intensity of the effect of response time on the complex of CXT and CPB in Test 1 (3);

Figure 4 is a graph showing the variation of CPB concentration versus CXT fluorescence intensity in Test 1 (4);

Figure 5 is a diagram of the fluorescence intensity changes against CXT when other common surfactants and inorganic salts compete with CPB in Test 1 (5); among them, 1 is CPB, 2 is CPB+CTAB, 3 is CPB+DTAB, and 4 is CPB+ SDS, 5 is CPB+SDBS, 6 is CPB+SPTS, 7 is CPB+OP–10, 8 is CPB+TritonX-100, 9 is CPB+Tween–20, 10 is CPB+F ^- , 11 is CPB+Cl ^- , 12 is CPB+Br ^- , 13 is CPB+I ^- , 14 is CPB+SCN ^- , 15 is CPB+PO ₄ ^3- , 16 is CPB+NO ^3- , 17 is CPB+NO ^2- , 18 is CPB+C ₂ O ₄ ^2- , 19 is CPB+CO ₃ ^2- , 20 is CPB+SO ₄ ^2- ;

Fig. 6 is a graph showing the linear relationship between the fluorescence intensity and the molar concentration of the CPB solution in test one (six);

Fig. 7 is a graph showing the linear relationship between the fluorescence intensity and the molar concentration of the N-DAPC solution in test two (six);

Fig. 8 is a graph showing the linear relationship between the fluorescence intensity and the molar concentration of the HPB solution in Test 3 (6).

detailed description

Embodiment one: the fluorescence detection method of the pyridinium quaternary ammonium salt cationic surfactant (RPB) of the present embodiment is carried out according to the following steps:

1. Configure the detection solution: add the fluorescent dye CXT, non-ionic surfactant and buffer solution into the water, adjust the pH value to pH 5-12 after mixing evenly, and obtain the detection solution; the molar concentration of CXT in the detection solution 1.0×10 ^-6 ~ 1.0×10 ^-3 mol/L; the nonionic surfactant in the detection solution is Brij35, and its molar concentration is 1.0×10 ^-5 ~ 1.0×10 ^-2 mol/L; The buffer solution in the detection solution mentioned above is Tris-HCl or Hepes, and its molar concentration is 0.1×10 ^-3 -2.0×10 ^-2 mol/L.

2. The single selectivity of RPB: Add various common surfactants respectively to the solution of step 1. When the concentration of surfactant is 1 to 6 times of the concentration of CXT, measure its fluorescence intensity (excitation wavelength is 340nm, maximum emission wavelength at 444nm).

3. Determination of response time: Add 5.0×10 ^-6 ~ 3.0×10 ^-5 mol/LRPB to the solution in step 1, and measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm).

4. Determination of RPB concentration: when the concentration of RPB is gradually added to the solution in step 1 to be 0 to 12 times the concentration of CXT, measure its fluorescence spectrum.

5. The influence of interfering substances: Add 5.0×10 ^-6 ~ 3.0×10 ^-5 mol/LRPB and other common surfactants and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP–3～30, TritonX–100, Tween–20, Tween–40, Tween–60, Tween–80, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^3- , NO ^{3 -} , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2– , SO ₄ ^2- ), RPB coexists with other surfactants and inorganic salts, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm) .

Six, determination of detection limit: when the concentration of gradually adding RPB in step one solution is 0～12 times of CXT concentration, measure its fluorescence intensity at 444nm place (excitation wavelength is 340nm, maximum emission wavelength is 444nm). When the RPB concentration is in the range of 0～3.0×10 ^-5 mol/L, the fluorescence intensity of the solution has a good linear relationship with the RPB concentration; 20 average measurements are carried out on the blank sample, and 3σ/K (σ is the standard deviation of the blank, K is the slope of the regression equation), the calculated detection limit is 8.2×10 ^-9 ～7.6×10 ^-8 mol/L, and the linear range is 8.2×10 ^-9 ～3.0×10 ^-5 mol/L.

7. Detection of the sample to be tested: After the sample to be tested is filtered and centrifuged at a centrifugal speed of 12000rpm, the supernatant is added to the detection solution obtained in step 1, and the fluorescence intensity is measured at a wavelength of 444nm. The linear regression equation obtained in step 6 calculates the content of RPB in the sample to be tested, and the recovery rate ranges from 98.9 to 102%.

The method of this embodiment utilizes fluorescence spectroscopy, and the fluorescent dye CXT (4,4'-bis-(4-hydroxyethylamino-anilino-1,3,5-triazin-2-yl)amino-stilbene- 2,2'-disulfonic acid sodium salt) as a fluorescent molecular probe, with Brij35 micellar aqueous solution as the medium, Tris-HCl or Hepes as the buffer solution, from common cationic surfactants, anionic surfactants and nonionic surface active agents Single selective detection of pyridinium quaternary ammonium cationic surfactants among active agents.

The method of this embodiment has the following advantages:

1. The present invention uses fluorescent dye CXT as a detection reagent, which can single-selectively detect pyridinium quaternary ammonium salt cationic surfactants. Fluorescent dye CXT is an excellent whitening agent with wide sources and low price. It is a special dye that can emit blue-violet fluorescence. It has the advantages of good spectral performance, high solubility and low pollution.

2. The present invention uses Tris-HCl or Hepes as a buffer solution, and uses Brij35 micellar aqueous solution as a medium, so that the solubility of CXT and pyridinium quaternary ammonium salt cationic surfactant in aqueous solution is better, and the low concentration below the millimolar concentration Concentration pyridinium quaternary ammonium cationic surfactant and CXT can form a stable complex, which can quench the fluorescence of CXT.

3. The method of the present invention is not affected by other common surfactants and inorganic salts, such as cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), lauryl Sodium sulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), sodium p-toluenesulfonate (SPTS), OP–3～30, TritonX–100, Tween–20, Tween–40, Tween–60, Tween–80, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^3- , NO ^3- , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2– , SO ₄ ^2- plasma effect with high selectivity.

4. The present invention not only avoids the cumbersome organic synthesis problem in the current research on fluorescent molecular probes of pyridinium quaternary ammonium salt cationic surfactants, but also has incomparable safety for synthetic probes.

5. The present invention provides a method for testing pyridine with simple operation, fast response time (2min), high selectivity, high sensitivity and low detection limit (8.2×10 ^-9 mol/L～7.6×10 ^-8 mol/L) Method for quaternary ammonium cationic surfactants.

6. The present invention can be applied to the detection of pyridinium quaternary ammonium salt cationic surfactants in actual environmental water samples, such as surface water, lake water and sewage.

Embodiment 2: This embodiment differs from Embodiment 1 in that: after mixing uniformly in Step 1, use HCl solution or NaOH solution to adjust the pH value of the detection solution obtained in Step 1 to pH 8. Others are the same as in the first embodiment.

Embodiment 3: This embodiment differs from Embodiment 1 to Embodiment 2 in that the molar concentration of CXT in the detection solution described in step 1 is 5.0×10 ^-6 . Others are the same as one of the specific embodiments 1 to 2.

Embodiment 4: This embodiment differs from Embodiments 1 to 3 in that the non-ionic surfactant in the detection solution described in step 1 is Brij35, and its molar concentration is 1.2×10 ^-3 mol/L. Others are the same as those in the first to third specific embodiments.

Embodiment 5: This embodiment differs from Embodiment 1 to Embodiment 4 in that: the buffer solution in the detection solution described in step 1 is Tris-HCl, and its molar concentration is 0.01 mol/L. Others are the same as one of the specific embodiments 1 to 4.

Embodiment 6: The difference between this embodiment and one of Embodiments 1 to 5 is that the concentration of the surfactant in step 2 is 1 times the concentration of CXT. Others are the same as one of the specific embodiments 1 to 5.

Embodiment 7: The difference between this embodiment and one of Embodiments 1 to 6 is that the surfactant concentration in step 2 is 4 times of the CXT concentration. Others are the same as one of the specific embodiments 1 to 6.

Embodiment 8: The difference between this embodiment and one of Embodiments 1 to 7 is that the surfactant concentration in step 2 is 6 times of the CXT concentration. Others are the same as one of the specific embodiments 1 to 7.

Embodiment 9: This embodiment differs from Embodiments 1 to 8 in that the concentration of RPB in step 3 is 5.0×10 ^-6 mol/L. Others are the same as one of the specific embodiments 1 to 8.

Embodiment 10: This embodiment differs from Embodiments 1 to 9 in that the concentration of RPB in step 3 is 2.0×10 ^-5 mol/L. Others are the same as one of the specific embodiments 1 to 9.

Embodiment 11: This embodiment differs from Embodiments 1 to 10 in that the concentration of RPB in step 3 is 3.0×10 ^-5 mol/L. Others are the same as those in Embodiments 1 to 11.

Embodiment 12: This embodiment differs from Embodiments 1 to 11 in that the concentration of RPB added in Step 4 is 0-4 times the concentration of CXT. Others are the same as those of the specific embodiments 1 to 11.

Embodiment 13: This embodiment is different from Embodiment 1 to Embodiment 12 in that: the concentration of RPB added in Step 4 is 0-10 times the concentration of CXT. Others are the same as one of the specific embodiments 1 to 12.

Embodiment 14: This embodiment differs from Embodiments 1 to 13 in that the concentration of RPB added in Step 4 is 0-12 times the concentration of CXT. Others are the same as those of the first to thirteenth specific embodiments.

Embodiment 15: This embodiment is different from one of Embodiment 1 to 14 in that: other common surfactants and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP-10, TritonX) in step 5 –100, Tween–20, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^3- , NO ^3- , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2- , SO ₄ ^{2 -} ). Others are the same as those in the first to fifteenth specific embodiments.

Embodiment 16: This embodiment differs from Embodiment 1 to Embodiment 15 in that: the calculated detection limit in step 6 is 6.3×10 ^-8 mol/L, and the linear range is 6.3×10 ^-8 ~ 2.0× 10 ^-5 mol/L. Others are the same as those in the first to fifteenth specific embodiments.

Embodiment 17: This embodiment differs from Embodiment 1 to Embodiment 16 in that the detection limit calculated in step 6 is 8.2×10 ^-9 mol/L, and the linear range is 8.2×10 ^-9 ~ 5.0× 10 ^-6 mol/L. Others are the same as one of the specific embodiments 1 to 16.

Embodiment 18: The difference between this embodiment and Embodiment 1 to 17 is that the detection limit calculated in step 6 is 7.6×10 ^-8 mol/L, and the linear range is 7.6×10 ^-8 ~ 3.0× 10 ^-5 mol/L. Others are the same as those of the first to seventeenth specific embodiments.

Embodiment Nineteen: The difference between this embodiment and Embodiment One to Embodiment Eighteen is that the recovery rate obtained in step seven ranges from 98.9% to 100.2%. Others are the same as those of the first to eighteenth specific embodiments.

Embodiment 20: This embodiment differs from Embodiments 1 to 19 in that the recovery rate obtained in step 7 ranges from 99.1 to 101.2%. Others are the same as those of the first to nineteenth specific embodiments.

Embodiment 21: This embodiment is different from Embodiments 1 to 21 in that: the recovery rate obtained in step 7 ranges from 99.0 to 102%. Others are the same as the first to twenty-first specific embodiments.

The method of the present invention will be further described below in conjunction with specific examples, so that those skilled in the art can clearly understand the present invention, but the following examples do not limit the scope of protection claimed by the present invention in any form.

Test 1: Specific detection method of cetylpyridinium bromide (CPB) cationic surfactant:

(1) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with a CXT concentration of 5.0×10 ^-6 mol/L was added to various common Surfactants (CTAB, DTAB, SDS, SDBS, SPTS, OP-10, TritonX-100, Tween-20, CPB), when the concentration is 4 times the concentration of CXT, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength at 444nm). Only CPB can significantly quench the fluorescence of the solution, while other surfactants have little effect on the fluorescence spectrum of the solution. It shows that the fluorescent probe of the present invention can single-selectively detect CPB in common surfactants. Wherein: the ordinate represents the fluorescence intensity at the maximum emission wavelength (444nm), and the abscissa represents the type of surfactant.

(2) Adjust the pH value of 5.0×10 ^-6 mol/L CXT aqueous solution and 2.0×10 ^-5 mol/LCPB containing CXT water (1.2×10 ^-3 mol/LBrij35) solution with HCl or NaOH solution, and measure The fluorescence intensity of the solution changes with the pH value. Comparing the two curves of fluorescence intensity changing with the pH value, it can be seen that when the pH value is greater than 5, CXT and CPB form a stable complex, resulting in a significant quenching of the solution fluorescence. It shows that CXT can be used for the detection of CPB when the pH value is greater than 5. Wherein: the ordinate represents the fluorescence intensity at the maximum emission wavelength (444nm), and the abscissa represents the pH value.

( ³ ) ^Add 2.0× ^{10 -5} mol/L CPB, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the increase of time, the fluorescence intensity of the probe molecule at 444nm decreased obviously, and when the response time exceeded 2min, the fluorescence intensity of the probe molecule tended to be stable. Indicating that the response time of CXT to CPB is rapid. Wherein: the ordinate represents the fluorescence intensity at the maximum emission wavelength (444nm), and the abscissa represents the response time (t/min).

(4) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of CPB is the concentration of CXT Measure the fluorescence spectrum at 0-10 times. With the addition of CPB, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually. Wherein: the ordinate represents the fluorescence intensity, and the abscissa represents the fluorescence emission wavelength (λ _em /nm, the excitation wavelength is 340nm).

(5) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add CPB and other common Surfactants and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP–10, TritonX-100, Tween–20, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^3- , NO ^3- , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2- , SO ₄ ^2- ), CPB coexisted with other surfactants and inorganic salts, and when the concentration was 4 times that of CXT, the fluorescence was measured ( The excitation wavelength is 340nm, and the maximum emission wavelength is 444nm). Other common surfactants and inorganic salts did not significantly interfere with the fluorescence emission of the CPB complex, and its fluorescence intensity was similar to that when only CPB existed in the solution. It shows that the fluorescence detection of CPB by CXT is not affected by other common surfactants and inorganic salts. Wherein: the ordinate represents the fluorescence intensity at the maximum emission wavelength (444nm), and the abscissa represents the types of surfactants and inorganic salts.

(6) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of CPB is the concentration of CXT At 0-10 times, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the addition of CPB, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually. When the CPB concentration is in the range of 0～2.0×10 ^-5 mol/L, the fluorescence intensity of the solution has a good linear relationship with the CPB concentration (R ² =0.9956), and its linear regression equation is y=-5.5939x+182.58; The blank sample was averaged 20 times, according to 3σ/K (σ is the standard deviation of the blank, K is the slope of the regression equation), the calculated detection limit is 6.3×10 ^-8 mol/L, and the linear range is 6.3×10 ^-8 ～2.0 ×10 ^-5 mol/L. It shows that the fluorescent reagent of the present invention can detect CPB with high sensitivity.

(7) The following is the application of CXT in the study of actual environmental water samples. Taking surface water and lake water as the research objects, the surface water and lake water were filtered with qualitative filter paper, and then separated by a centrifuge at 12000rpm. The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add CPB aqueous solution, and the final concentrations are respectively 5.00, 10.0, 15.0 and 20.0 μM. With excitation at 340 nm, the fluorescence emission intensity at 444 nm was recorded. By comparing with the quantitative standard curve, the actual detection concentration of CPB was obtained, and the recovery rate was calculated, and good experimental results were obtained. The recovery rate was between 98.9% and 100.2%, as shown in Table 1. The results show that it can be applied to the detection of CPB in actual environmental water samples.

Table 1 CPB detection data in surface water and lake water samples

Test 2: The specific detection method of N-dodecylacetyl chloride pyridinium (N-DAPC) cationic surfactant:

(1) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with a CXT concentration of 5.0×10 ^-6 mol/L was added to various common Surfactants (CTAB, DTAB, SDS, SDBS, SPTS, OP-10, TritonX-100, Tween-20, N-DAPC), when the concentration is 1 times the concentration of CXT, measure its fluorescence (excitation wavelength is 340nm, maximum The emission wavelength is 444nm). Only N-DAPC caused significant quenching of the solution fluorescence, while other surfactants had no obvious effect on the solution fluorescence spectrum. It shows that the fluorescent probe of the present invention can single-selectively detect N-DAPC in common surfactants.

(2) Adjust the pH value of 5.0×10 ^-6 mol/L CXT aqueous solution and 5.0×10 ^-6 mol/L N-DAPC containing CXT water (1.2×10 ^-3 mol/LBrij35) solution with HCl or NaOH solution , to measure the change of the fluorescence intensity of the solution with the pH value. Comparing the two curves of fluorescence intensity with pH value, it can be seen that when the pH value is greater than 5, CXT and N-DAPC form a stable complex, resulting in a significant quenching of the solution fluorescence. It shows that CXT can be used for the detection of N-DAPC when the pH value is greater than 5.

( ³ ) ^{Add 5.0} ×10 ^-6 mol/L N-DAPC, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the increase of time, the fluorescence intensity of the probe molecule at 444nm decreased obviously, and when the response time exceeded 2min, the fluorescence intensity of the probe molecule tended to be stable. It shows that the response time of CXT to N-DAPC is rapid.

(4) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of N-DAPC is CXT When the concentration is 0-4 times, measure its fluorescence spectrum. With the addition of N-DAPC, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually.

(5) Add ^{N - DAPC} and Other common surfactants and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP–10, TritonX-100, Tween–20, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^{3 -} , NO ^3- , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2- , SO ₄ ^2- ), N-DAPC coexists with other surfactants and inorganic salts, when the concentration is 1 times the concentration of CXT, Measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). Other common surfactants and inorganic salts do not significantly interfere with the fluorescence emission of the N-DAPC complex, and its fluorescence intensity is similar to that when only N-DAPC exists in the solution. It shows that the fluorescence detection of N-DAPC by CXT is not affected by other common surfactants and inorganic salts.

(6) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of N-DAPC is CXT When the concentration is 0-4 times, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the addition of N-DAPC, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually. When the concentration of N-DAPC is in the range of 0～5.0×10 ^-6 mol/L, the fluorescence intensity of the solution has a good linear relationship with the concentration of N-DAPC (R ² =0.9901), and the linear regression equation is y=-23.028x +177.17; 20 times the average measurement of the blank sample, according to 3σ/K (σ is the standard deviation of the blank, K is the slope of the regression equation), the calculated detection limit is 8.2×10 ^-9 mol/L, and the linear range is 8.2×10 ^-9 ~ 5.0×10 ^-6 mol/L. It shows that the fluorescent reagent of the present invention can detect N-DAPC with high sensitivity.

(7) The following is the application of the fluorescent probe CXT in the study of actual environmental water samples. Taking surface water and lake water as the research objects, the surface water and lake water were filtered with qualitative filter paper, and then separated by a centrifuge at 12000rpm. The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add N-DAPC aqueous solution, to the final concentration 1.0, 2.0, 3.0 and 4.0 μM, respectively. With excitation at 340 nm, the fluorescence emission intensity at 444 nm was recorded. By comparing with the quantitative standard curve, the actual detection concentration of N-DAPC was obtained, and the recovery rate was calculated. Good experimental results were obtained, and the recovery rate was between 99.1% and 101.2%. The results show that it can be applied to the detection of N-DAPC in actual environmental water samples.

Test 3: The specific detection method of mixed alkyl pyridinium quaternary ammonium salt cationic surfactant (WPB) with different carbon numbers (8-18):

(1) Water (1.0×10 ^-2 mol/LHepes, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with a concentration of CXT of 5.0×10 ^-6 mol/L, adding various common surfactants (CTAB, DTAB, SDS, SDBS, SPTS, OP-10, TritonX-100, Tween-20, WPB), when the concentration is 6 times of CXT concentration, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm ). Only WPB led to significant quenching of the solution fluorescence, while other surfactants had no obvious effect on the solution fluorescence spectrum.

(2) Adjust the pH value of 5.0×10 ^-6 mol/L CXT aqueous solution and 3.0×10 ^-5 mol/LTPC-containing CXT water (1.2×10 ^-3 mol/LBrij35) solution with HCl or NaOH solution, and measure The fluorescence intensity of the solution changes with the pH value. Comparing the two curves of fluorescence intensity with pH value, it can be seen that when the pH value is greater than 5, CXT and WPB form a stable complex, resulting in a significant quenching of the solution fluorescence.

( ³ ) ^{Add 3.0×10 -5 mol /} For WPB of L, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the increase of time, the fluorescence intensity of the probe molecule at 444nm decreased obviously, and when the response time exceeded 2min, the fluorescence intensity of the probe molecule tended to be stable. Indicates that the response time of CXT to WPB is rapid.

(4) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/L Hepes, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of WPB is 0– At 12 times, measure its fluorescence spectrum. With the addition of HPB, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually.

(5) Water (1.0×10 ^-2 mol/LHepes, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with a CXT concentration of 5.0×10 ^-6 mol/L, add WPB and other common surface Active agents and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP–10, TritonX-100, Tween–20, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^3- , NO ^{3 -} , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2- , SO ₄ ^2- ), WPB coexists with other surfactants and inorganic salts, when the concentration is 6 times that of CXT, measure its fluorescence (excitation wavelength 340nm, the maximum emission wavelength is 444nm). Other common surfactants and inorganic salts did not significantly interfere with the fluorescence emission of the WPB complex, and its fluorescence intensity was similar to that when only WPB existed in the solution. It indicated that the fluorescence detection of WPB by CXT was not affected by other common surfactants and inorganic salts.

(6) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/L Hepes, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of WPB is 0– At 12 times, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the addition of WPB, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually. When the concentration of HPB is in the range of 0～3.0×10 ^-5 mol/L, the fluorescence intensity of the solution has a good linear relationship with the concentration of WPB (R ² =0.9978), and the linear regression equation is y=-4.3856x+192.82; The blank sample was averaged 20 times, according to 3σ/K (σ is the standard deviation of the blank, K is the slope of the regression equation), the calculated detection limit is 7.6×10 ^-8 mol/L, and the linear range is 7.6×10 ^-8 ～3.0 ×10 ^-5 mol/L. It shows that the fluorescent reagent of the present invention can detect WPB with high sensitivity.

(7) The following is the application of the fluorescent probe CXT in the study of actual environmental water samples. Taking surface water and lake water as the research objects, the surface water and lake water were filtered with qualitative filter paper, and then separated by a centrifuge at 12000rpm. The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LHepes, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add WPB aqueous solution, the final concentration is 5.00, 15.0, 20.0 and 25.0 μM. With excitation at 340 nm, the fluorescence emission intensity at 444 nm was recorded. By comparing with the quantitative standard curve, the actual detection concentration of WPB was obtained, and the recovery rate was calculated. Good experimental results were obtained, and the recovery rate was between 99.4-101.8%. The results show that it can be applied to the detection of WPB in actual environmental water samples.

Test 4: The specific detection method of tetradecylpyridinium chloride (TPC) cationic surfactant:

(1) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with a CXT concentration of 5.0×10 ^-6 mol/L was added to various common Surfactants (CTAB, DTAB, SDS, SDBS, SPTS, OP-10, TritonX-100, Tween-20, TPC), when the concentration is 4 times the concentration of CXT, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength at 444nm). Only TPC resulted in significant quenching of the solution fluorescence, while other surfactants had no significant effect on the solution fluorescence spectra.

(2) Adjust the pH value of 5.0×10 ^-6 mol/L CXT aqueous solution and 2.0×10 ^-5 mol/LTPC (1.2×10 ^-3 mol/LBrij35) solution with HCl or NaOH solution to determine The fluorescence intensity of the solution changes with the pH value. Comparing the two curves of fluorescence intensity changing with the pH value, it can be seen that when the pH value is greater than 5, CXT and TPC form a stable complex, resulting in a significant quenching of the solution fluorescence.

( ³ ) ^Add 2.0× ^{10 -5} mol/L TPC, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the increase of time, the fluorescence intensity of the probe molecule at 444nm decreased obviously, and when the response time exceeded 2min, the fluorescence intensity of the probe molecule tended to be stable. Indicating that the response time of CXT to TPC is rapid.

(4) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of TPC is the concentration of CXT Measure the fluorescence spectrum at 0-10 times. With the addition of TPC, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually.

(5 ^{) Add TPC} and other common Surfactants and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP–10, TritonX-100, Tween–20, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^3- , NO ^3- , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2– , SO ₄ ^2- ), TPC coexisted with other surfactants and inorganic salts, when the concentration was 4 times that of CXT, the fluorescence was measured ( The excitation wavelength is 340nm, and the maximum emission wavelength is 444nm). Other common surfactants and inorganic salts do not significantly interfere with the fluorescence emission of the TPC complex, and its fluorescence intensity is similar to that when only TPC exists in the solution. It shows that the fluorescence detection of TPC by CXT is not affected by other common surfactants and inorganic salts.

(6) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with CXT concentration of 5.0×10 ^-6 mol/L, TPC concentration of CXT concentration At 0-10 times, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the addition of TPC, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually. When the TPC concentration is in the range of 0～2.0×10 ^-5 mol/L, the fluorescence intensity of the solution has a good linear relationship with the TPC concentration (R ² =0.9956), and its linear regression equation is y=-5.5939x+182.58; The blank sample was averaged 20 times, according to 3σ/K (σ is the standard deviation of the blank, K is the slope of the regression equation), the calculated detection limit is 6.3×10 ^-8 mol/L, and the linear range is 6.3×10 ^-8 ～2.0 ×10 ^-5 mol/L. It shows that the fluorescent reagent of the present invention can detect TPC with high sensitivity.

(7) The following is the application of the fluorescent probe CXT in the study of actual environmental water samples. Taking surface water and lake water as the research objects, the surface water and lake water were filtered with qualitative filter paper, and then separated by a centrifuge at 12000rpm. The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add TPC aqueous solution, and the final concentrations are 5.00, 10.0, 15.0 and 20.0 μM. With excitation at 340 nm, the fluorescence emission intensity at 444 nm was recorded. By comparing with the quantitative standard curve, the actual detection concentration of TPC was obtained, and the recovery rate was calculated. Good experimental results were obtained, and the recovery rate was between 98.9% and 100.2%. The results show that it can be applied to the detection of TPC in actual environmental water samples.

Experiment 5: The specific detection method of dodecylpyridinium bromide (DPB) cationic surfactant:

(1) Water (1.0×10 ^-2 mol/LHepes, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with a concentration of CXT of 5.0×10 ^-6 mol/L, adding various common surfactants (CTAB, DTAB, SDS, SDBS, SPTS, OP-10, TritonX-100, Tween-20, DPB), when the concentration is 4 times of CXT concentration, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm ). Only DPB can significantly quench the fluorescence of the solution, while other surfactants have little effect on the fluorescence spectrum of the solution.

(2) Adjust the pH value of 5.0×10 ^-6 mol/L CXT aqueous solution and 2.0×10 ^-5 mol/LDPB containing CXT water (1.2×10 ^-3 mol/LBrij35) solution with HCl or NaOH solution, and measure The fluorescence intensity of the solution changes with the pH value. Comparing the two curves of fluorescence intensity with pH value, it can be seen that when the pH value is greater than 5, CXT and DPB form a stable complex, resulting in a significant quenching of the solution fluorescence.

( ³ ) ^{Add 2.0×10 -5 mol /} For the DPB of L, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the increase of time, the fluorescence intensity of the probe molecule at 444nm decreased obviously, and when the response time exceeded 2min, the fluorescence intensity of the probe molecule tended to be stable. It shows that the response time of CXT to DPB is fast.

(4) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/L Hepes, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of DPB is 0– At 10 times, measure its fluorescence spectrum. With the addition of DPB, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually.

(5) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LHepes, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add DPB and other common surface Active agents and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP–10, TritonX-100, Tween–20, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^3- , NO ^{3 -} , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2– , SO ₄ ^2- ), when DPB coexists with other surfactants and inorganic salts, when the concentration is 4 times that of CXT, measure its fluorescence (excitation wavelength 340nm, the maximum emission wavelength is 444nm). Other common surfactants and inorganic salts do not significantly interfere with the fluorescence emission of the DPB complex, and its fluorescence intensity is similar to that when only DPB exists in the solution. It shows that the fluorescence detection of CXT on DPB is not affected by other common surfactants and inorganic salts.

(6) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/L Hepes, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of DPB is 0– At 10 times, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the addition of DPB, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually. When the DPB concentration is in the range of 0～2.0×10 ^-5 mol/L, the fluorescence intensity of the solution has a good linear relationship with the DPB concentration (R ² =0.9956), and its linear regression equation is y=-5.5939x+182.58; The blank sample was averaged 20 times, according to 3σ/K (σ is the standard deviation of the blank, K is the slope of the regression equation), the calculated detection limit is 6.3×10 ^-8 mol/L, and the linear range is 6.3×10 ^-8 ～2.0 ×10 ^-5 mol/L. It shows that the fluorescent reagent of the present invention can detect DPB with high sensitivity.

(7) The following is the application of the fluorescent probe CXT in the study of actual environmental water samples. Taking surface water and lake water as the research objects, the surface water and lake water were filtered with qualitative filter paper, and then separated by a centrifuge at 12000rpm. The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LHepes, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add DPB aqueous solution, and the final concentration is 5.00, 10.0, 15.0 and 20.0 μM. With excitation at 340 nm, the fluorescence emission intensity at 444 nm was recorded. By comparing with the quantitative standard curve, the actual detection concentration of DPB was obtained, and the recovery rate was calculated. Good experimental results were obtained, and the recovery rate was between 98.9% and 100.2%. The results show that it can be applied to the detection of DPB in actual environmental water samples.

Test 6: The specific detection method of octadecylpyridine chloride (OPC) cationic surfactant:

(1) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with a CXT concentration of 5.0×10 ^-6 mol/L was added to various common Surfactants (CTAB, DTAB, SDS, SDBS, SPTS, OP-10, TritonX-100, Tween-20, OPC), when the concentration is 4 times the concentration of CXT, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength at 444nm). Only OPC led to significant quenching of the solution fluorescence, while other surfactants had no obvious effect on the solution fluorescence spectrum.

(2) Adjust the pH value of 5.0×10 ^-6 mol/L CXT aqueous solution and 2.0×10 ^-5 mol/LOPC-containing CXT water (1.2×10 ^-3 mol/LBrij35) solution with HCl or NaOH solution, and measure The fluorescence intensity of the solution changes with the pH value. Comparing the two curves of fluorescence intensity changing with the pH value, it can be seen that when the pH value is greater than 5, CXT and OPC form a stable complex, resulting in a significant quenching of the solution fluorescence.

( ³ ) ^Add 2.0× ^{10 -5} mol/L OPC, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the increase of time, the fluorescence intensity of the probe molecule at 444nm decreased obviously, and when the response time exceeded 2min, the fluorescence intensity of the probe molecule tended to be stable. Indicates that the response time of CXT to OPC is fast.

(4) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with CXT concentration of 5.0×10 ^-6 mol/L, OPC concentration of CXT concentration Measure the fluorescence spectrum at 0-10 times. With the addition of OPC, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually.

(5 ^{) Add OPC} and other common Surfactants and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP–10, TritonX-100, Tween–20, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^3- , NO ^3- , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2– , SO ₄ ^2- ), OPC coexists with other surfactants and inorganic salts, when the concentration is 4 times that of CXT, measure its fluorescence ( The excitation wavelength is 340nm, and the maximum emission wavelength is 444nm). Other common surfactants and inorganic salts do not significantly interfere with the fluorescence emission of the OPC complex, and its fluorescence intensity is similar to that when only OPC exists in the solution. It shows that the fluorescence detection of OPC by CXT is not affected by other common surfactants and inorganic salts.

(6) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the OPC concentration is the concentration of CXT At 0-10 times, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the addition of OPC, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually. When the OPC concentration is in the range of 0～2.0×10 ^-5 mol/L, the fluorescence intensity of the solution has a good linear relationship with the OPC concentration (R ² =0.9956), and its linear regression equation is y=-5.5939x+182.58; The blank sample was averaged 20 times, according to 3σ/K (σ is the standard deviation of the blank, K is the slope of the regression equation), the calculated detection limit is 6.3×10 ^-8 mol/L, and the linear range is 6.3×10 ^-8 ～2.0 ×10 ^-5 mol/L. It shows that the fluorescent reagent of the present invention can detect OPC with high sensitivity.

(7) The following is the application of the fluorescent probe CXT in the study of actual environmental water samples. Taking surface water and lake water as the research objects, the surface water and lake water were filtered with qualitative filter paper, and then separated by a centrifuge at 12000rpm. The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add OPC aqueous solution, and the final concentrations are respectively 5.00, 15.0, 20.0 and 25.0 μM. With excitation at 340 nm, the fluorescence emission intensity at 444 nm was recorded. By comparing with the quantitative standard curve, the actual detection concentration of OPC was obtained, and the recovery rate was calculated. Good experimental results were obtained, and the recovery rate was between 98.9-100.2%. The results show that it can be applied to the detection of OPC in actual environmental water samples.

Experiment 7: The specific detection method of N-tetradecylacetyl chloride pyridinium (N-DTPC) cationic surfactant:

(1) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with a CXT concentration of 5.0×10 ^-6 mol/L was added to various common Surfactants (CTAB, DTAB, SDS, SDBS, SPTS, OP-10, TritonX-100, Tween-20, N-DTPC), when the concentration is 1 times the concentration of CXT, measure its fluorescence (excitation wavelength is 340nm, maximum The emission wavelength is 444nm). Only N-DTPC resulted in significant quenching of the solution fluorescence, while other surfactants had no significant effect on the solution fluorescence spectra. It shows that the fluorescent probe of the present invention can single-selectively detect N-DTPC in common surfactants.

(2) Adjust the pH value of 5.0×10 ^-6 mol/L CXT aqueous solution and 5.0×10 ^-6 mol/L N-DAPC containing CXT water (1.2×10 ^-3 mol/LBrij35) solution with HCl or NaOH solution , to measure the change of the fluorescence intensity of the solution with the pH value. Comparing the two curves of fluorescence intensity with pH value, it can be seen that when the pH value is greater than 5, CXT and N-DTPC form a stable complex, resulting in a significant quenching of the solution fluorescence. It shows that CXT can be used for the detection of N-DTPC when the pH value is greater than 5.

( ³ ) ^{Add 5.0} ×10 ^-6 mol/L N-DTPC, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the increase of time, the fluorescence intensity of the probe molecule at 444nm decreased obviously, and when the response time exceeded 2min, the fluorescence intensity of the probe molecule tended to be stable. It shows that the response time of CXT to N-DTPC is rapid.

(4) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of N-DTPC is CXT When the concentration is 0-4 times, measure its fluorescence spectrum. With the addition of N-DTPC, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually.

(5) Add ^{N - DTPC} and Other common surfactants and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP–10, TritonX-100, Tween–20, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^{3 -} , NO ^3- , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2– , SO ₄ ^2- ), N-DTPC coexists with other surfactants and inorganic salts, when the concentration is 1 times the concentration of CXT, Measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). Other common surfactants and inorganic salts do not significantly interfere with the fluorescence emission of the N-DTPC complex, and its fluorescence intensity is similar to that when only N-DTPC exists in the solution. It shows that the fluorescence detection of N-DTPC by CXT is not affected by other common surfactants and inorganic salts.

(6) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of N-DTPC is CXT When the concentration is 0-4 times, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the addition of N-DTPC, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually. When the concentration of N-DTPC is in the range of 0～5.0×10 ^-6 mol/L, the fluorescence intensity of the solution has a good linear relationship with the concentration of N-DTPC (R ² =0.9901), and the linear regression equation is y=-23.028x +177.17; 20 times the average measurement of the blank sample, according to 3σ/K (σ is the standard deviation of the blank, K is the slope of the regression equation), the calculated detection limit is 8.2×10 ^-9 mol/L, and the linear range is 8.2×10 ^-9 ~ 5.0×10 ^-6 mol/L. It shows that the fluorescent reagent of the present invention can detect N-DTPC with high sensitivity.

(7) The following is the application of the fluorescent probe CXT in the study of actual environmental water samples. Taking surface water and lake water as the research objects, the surface water and lake water were filtered with qualitative filter paper, and then separated by a centrifuge at 12000rpm. The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add N-DTPC aqueous solution, to the final concentration 1.0, 2.0, 3.0 and 4.0 μM, respectively. With excitation at 340 nm, the fluorescence emission intensity at 444 nm was recorded. By comparing with the quantitative standard curve, the actual detection concentration of N-DAPC was obtained, and the recovery rate was calculated. Good experimental results were obtained, and the recovery rate was between 99.1% and 101.2%. The results show that it can be applied to the detection of N-DTPC in actual environmental water samples.

Test 8: The specific detection method of N-hexadecylacetylpyridine bromide (N-DCPB) cationic surfactant:

(1) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with a CXT concentration of 5.0×10 ^-6 mol/L was added to various common Surfactants (CTAB, DTAB, SDS, SDBS, SPTS, OP-10, TritonX-100, Tween-20, N-DCPB), when the concentration is 1 times the concentration of CXT, measure its fluorescence (excitation wavelength is 340nm, maximum The emission wavelength is 444nm). Only N-DCPB caused significant quenching of the solution fluorescence, while other surfactants had no obvious effect on the solution fluorescence spectrum. It shows that the fluorescent probe of the present invention can single-selectively detect N-DCPB in common surfactants.

(2) Adjust the pH value of 5.0×10 ^-6 mol/L CXT aqueous solution and 5.0×10 ^-6 mol/L N-DCPB containing CXT water (1.2×10 ^-3 mol/LBrij35) solution with HCl or NaOH solution , to measure the change of the fluorescence intensity of the solution with the pH value. Comparing the two curves of fluorescence intensity with pH value, it can be seen that when the pH value is greater than 5, CXT and N-DCPB form a stable complex, resulting in a significant quenching of the solution fluorescence. It shows that CXT can be used for the detection of N-DCPB when the pH value is greater than 5.

( ³ ) ^{Add 5.0} ×10 ^-6 mol/L N-DCPB, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the increase of time, the fluorescence intensity of the probe molecule at 444nm decreased obviously, and when the response time exceeded 2min, the fluorescence intensity of the probe molecule tended to be stable. It shows that the response time of CXT to N-DCPB is rapid.

(4) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of N-DCPB is CXT When the concentration is 0-4 times, measure its fluorescence spectrum. With the addition of N-DAPC, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually.

( ⁵ ) Add N ^{- DCPB} and Other common surfactants and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP–10, TritonX-100, Tween–20, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^{3 -} , NO ^3- , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2– , SO ₄ ^2- ), N-DCPB coexists with other surfactants and inorganic salts, when the concentration is 1 times the concentration of CXT, Measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). Other common surfactants and inorganic salts do not significantly interfere with the fluorescence emission of the N-DCPB complex, and its fluorescence intensity is similar to that when only N-DCPB exists in the solution. It shows that the fluorescence detection of N-DCPB by CXT is not affected by other common surfactants and inorganic salts.

(6) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of N-DCPB is CXT When the concentration is 0-4 times, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the addition of N-DCPB, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually. When the concentration of N-DCPB is in the range of 0～5.0×10 ^-6 mol/L, the fluorescence intensity of the solution has a good linear relationship with the concentration of N-DCPB (R ² =0.9901), and the linear regression equation is y=-23.028x +177.17; 20 times the average measurement of the blank sample, according to 3σ/K (σ is the standard deviation of the blank, K is the slope of the regression equation), the calculated detection limit is 8.2×10 ^-9 mol/L, and the linear range is 8.2×10 ^-9 ~ 5.0×10 ^-6 mol/L. It shows that the fluorescent reagent of the present invention can detect N-DCPB with high sensitivity.

(7) The following is the application of the fluorescent probe CXT in the study of actual environmental water samples. Taking surface water and lake water as the research objects, the surface water and lake water were filtered with qualitative filter paper, and then separated by a centrifuge at 12000rpm. The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add N-DCPB aqueous solution, to the final concentration 1.0, 2.0, 3.0 and 4.0 μM, respectively. With excitation at 340 nm, the fluorescence emission intensity at 444 nm was recorded. By comparing with the quantitative standard curve, the actual detection concentration of N-DCPB was obtained, and the recovery rate was calculated. Good experimental results were obtained, and the recovery rate was between 99.1% and 101.2%. The results show that it can be applied to the detection of N-DCPB in actual environmental water samples.

Test 9: The specific detection method of N-octadecylacetyliodopyridine (N-DOPI) cationic surfactant:

(1) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with a CXT concentration of 5.0×10 ^-6 mol/L was added to various common Surfactants (CTAB, DTAB, SDS, SDBS, SPTS, OP-10, TritonX-100, Tween-20, N-DOPI), when the concentration is 1 times the concentration of CXT, measure its fluorescence (excitation wavelength is 340nm, maximum The emission wavelength is 444nm). Only N-DOPI caused significant quenching of the solution fluorescence, while other surfactants had no obvious effect on the solution fluorescence spectrum. It shows that the fluorescent probe of the present invention can single-selectively detect N-DOPI in common surfactants.

(2) Adjust the pH value of 5.0×10 ^-6 mol/L CXT aqueous solution and 5.0×10 ^-6 mol/L N-DOPI-containing CXT water (1.2×10 ^-3 mol/LBrij35) solution with HCl or NaOH solution , to measure the change of the fluorescence intensity of the solution with the pH value. Comparing the two curves of fluorescence intensity with pH value, it can be seen that when the pH value is greater than 5, CXT and N-DOPI form a stable complex, resulting in a significant quenching of the solution fluorescence. It shows that CXT can be used for the detection of N-DOPI when the pH value is greater than 5.

( ³ ) ^{Add 5.0} ×10 ^-6 mol/L N-DOPI, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the increase of time, the fluorescence intensity of the probe molecule at 444nm decreased obviously, and when the response time exceeded 2min, the fluorescence intensity of the probe molecule tended to be stable. It shows that the response time of CXT to N-DOPI is rapid.

(4) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of N-DOPI is CXT When the concentration is 0-4 times, measure its fluorescence spectrum. With the addition of N-DOPI, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually.

( ⁵ ) Add N ^{- DOPI} and Other common surfactants and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP–10, TritonX-100, Tween–20, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^{3 -} , NO ^3- , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2– , SO ₄ ^2- ), N-DOPI coexists with other surfactants and inorganic salts, when the concentration is 1 times that of CXT, Measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). Other common surfactants and inorganic salts do not significantly interfere with the fluorescence emission of the N-DOPI complex, and its fluorescence intensity is similar to that when only N-DOPI exists in the solution. It shows that the fluorescence detection of N-DOPI by CXT is not affected by other common surfactants and inorganic salts.

(6) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of N-DOPI is CXT When the concentration is 0-4 times, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the addition of N-DOPI, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually. When the concentration of N-DOPI is in the range of 0～5.0×10 ^-6 mol/L, the fluorescence intensity of the solution has a good linear relationship with the concentration of N-DOPI (R ² =0.9901), and the linear regression equation is y=-23.028x +177.17; 20 times the average measurement of the blank sample, according to 3σ/K (σ is the standard deviation of the blank, K is the slope of the regression equation), the calculated detection limit is 8.2×10 ^-9 mol/L, and the linear range is 8.2×10 ^-9 ~ 5.0×10 ^-6 mol/L. It shows that the fluorescent reagent of the present invention can detect N-DOPI with high sensitivity.

(7) The following is the application of the fluorescent probe CXT in the study of actual environmental water samples. Taking surface water and lake water as the research objects, the surface water and lake water were filtered with qualitative filter paper, and then separated by a centrifuge at 12000rpm. The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add N-DOPI aqueous solution, to the final concentration 1.0, 2.0, 3.0 and 4.0 μM, respectively. With excitation at 340 nm, the fluorescence emission intensity at 444 nm was recorded. By comparing with the quantitative standard curve, the actual detection concentration of N-DOPI was obtained, and the recovery rate was calculated. Good experimental results were obtained, and the recovery rate was between 99.1% and 101.2%. The results show that it can be applied to the detection of N-DOPI in actual environmental water samples.

Experiment 10: Specific detection methods for mixed amide pyridine quaternary ammonium salt cationic surfactants (NPB) with different carbon numbers (8-18):

(1) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with a CXT concentration of 5.0×10 ^-6 mol/L was added to various common Surfactants (CTAB, DTAB, SDS, SDBS, SPTS, OP-10, TritonX-100, Tween-20, NPB), when the concentration is 1 times the concentration of CXT, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength at 444nm). Only NPB resulted in significant quenching of the solution fluorescence, while other surfactants had no significant effect on the solution fluorescence spectra. It shows that the fluorescent probe of the present invention can single-selectively detect NPB in common surfactants.

(2) Adjust the pH value of 5.0×10 ^-6 mol/L CXT aqueous solution and 5.0×10 ^-6 mol/L NPB containing CXT water (1.2×10 ^-3 mol/LBrij35) solution with HCl or NaOH solution, and measure The fluorescence intensity of the solution changes with the pH value. Comparing the two curves of fluorescence intensity with pH value, it can be seen that when the pH value is greater than 5, CXT and N-DOPI form a stable complex, resulting in a significant quenching of the solution fluorescence. It shows that CXT can be used for the detection of NPB when the pH value is greater than 5.

( ³ ) ^{Add 5.0} ×10 ^-6 mol/L NPB, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the increase of time, the fluorescence intensity of the probe molecule at 444nm decreased obviously, and when the response time exceeded 2min, the fluorescence intensity of the probe molecule tended to be stable. Indicating that the response time of CXT to NPB is rapid.

(4) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with CXT concentration of 5.0×10 ^-6 mol/L, NPB concentration of CXT concentration Measure the fluorescence spectrum at 0-4 times. With the addition of NPB, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually.

(5) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add NPB and other common Surfactants and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP–10, TritonX-100, Tween–20, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^3- , NO ^3- , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2– , SO ₄ ^2- ), NPB coexisted with other surfactants and inorganic salts, when the concentration was 1 times that of CXT, the fluorescence was measured ( The excitation wavelength is 340nm, and the maximum emission wavelength is 444nm). Other common surfactants and inorganic salts did not significantly interfere with the fluorescence emission of the NPB complex, and its fluorescence intensity was similar to that when only NPB existed in the solution. It shows that the fluorescence detection of NPB by CXT is not affected by other common surfactants and inorganic salts.

(6) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of NPB is the concentration of CXT At 0-4 times, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the addition of NPB, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually. When the NPB concentration is in the range of 0～5.0×10 ^-6 mol/L, the fluorescence intensity of the solution has a good linear relationship with the NPB concentration (R ² =0.9901), and its linear regression equation is y=-23.028x+177.17; The blank sample was averaged 20 times, according to 3σ/K (σ is the standard deviation of the blank, K is the slope of the regression equation), the calculated detection limit is 8.2×10 ^-9 mol/L, and the linear range is 8.2×10 ^-9 ～5.0 ×10 ^- 6mol/L. It shows that the fluorescent reagent of the present invention can detect NPB with high sensitivity.

(7) The following is the application of the fluorescent probe CXT in the study of actual environmental water samples. Taking surface water and lake water as the research objects, the surface water and lake water were filtered with qualitative filter paper, and then separated by a centrifuge at 12000rpm. The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add NPB aqueous solution, and the final concentrations are respectively 1.0, 2.0, 3.0 and 4.0 μM. With excitation at 340 nm, the fluorescence emission intensity at 444 nm was recorded. By comparing with the quantitative standard curve, the actual detection concentration of NPB was obtained, and the recovery rate was calculated. Good experimental results were obtained, and the recovery rate was between 99.1% and 101.2%. The results show that it can be applied to the detection of NPB in actual environmental water samples.

Experiment 11: Specific detection methods for mixed alkyl and amidopyridinium quaternary ammonium salt cationic surfactants (HPB) with different carbon numbers (8-18):

(1) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with a CXT concentration of 5.0×10 ^-6 mol/L was added to various common Surfactants (CTAB, DTAB, SDS, SDBS, SPTS, OP-10, TritonX-100, Tween-20, HPB), when the concentration is 6 times the concentration of CXT, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength at 444nm). Only HPB caused the solution fluorescence to be significantly quenched, while other surfactants had no obvious effect on the solution fluorescence spectrum.

(2) Adjust the pH value of 5.0×10 ^-6 mol/L CXT aqueous solution and 3.0×10 ^-5 mol/LTPC-containing CXT water (1.2×10 ^-3 mol/LBrij35) solution with HCl or NaOH solution, and measure The fluorescence intensity of the solution changes with the pH value. Comparing the two curves of fluorescence intensity changing with the pH value, it can be known that when the pH value is greater than 5, CXT and HPB form a stable complex, resulting in a significant quenching of the solution fluorescence.

( ³ ) ^Add 3.0× ^{10 -5} mol/L HPB, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the increase of time, the fluorescence intensity of the probe molecule at 444nm decreased obviously, and when the response time exceeded 2min, the fluorescence intensity of the probe molecule tended to be stable. Indicating that the response time of CXT to HPB is rapid.

(4) Water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution with CXT concentration of 5.0×10 ^-6 mol/L, HPB concentration of CXT concentration Measure the fluorescence spectrum at 0-12 times. With the addition of HPB, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually.

(5 ^{) Add HPB} and other common Surfactants and inorganic salts (CTAB, DTAB, SDS, SDBS, SPTS, OP–10, TritonX-100, Tween–20, F ^- , Cl ^- , Br ^- , I ^- , SCN ^- , PO ₄ ^3- , NO ^3- , NO ^2- , C ₂ O ₄ ^2- , CO ₃ ^2– , SO ₄ ^2- ), HPB coexisted with other surfactants and inorganic salts, when the concentration was 6 times that of CXT, the fluorescence was measured ( The excitation wavelength is 340nm, and the maximum emission wavelength is 444nm). Other common surfactants and inorganic salts do not significantly interfere with the fluorescence emission of the HPB complex, and its fluorescence intensity is similar to that when only HPB exists in the solution. It indicated that the fluorescence detection of HPB by CXT was not affected by other common surfactants and inorganic salts.

(6) The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, the concentration of HPB is the concentration of CXT At 0-12 times, measure its fluorescence (excitation wavelength is 340nm, maximum emission wavelength is 444nm). With the addition of HPB, the fluorescence peak intensity of the probe molecule at 444nm decreased gradually. When the HPB concentration is in the range of 0～3.0×10 ^-5 mol/L, the fluorescence intensity of the solution has a good linear relationship with the HPB concentration (R ² =0.9978), and its linear regression equation is y=-4.3856x+192.82; The blank sample was averaged 20 times, according to 3σ/K (σ is the standard deviation of the blank, K is the slope of the regression equation), the calculated detection limit is 7.6×10 ^-8 mol/L, and the linear range is 7.6×10 ^-8 ～3.0 ×10 ^-5 mol/L. It shows that the fluorescent reagent of the present invention can detect HPB with high sensitivity.

(7) The following is the application of the fluorescent probe CXT in the study of actual environmental water samples. Taking surface water and lake water as the research objects, the surface water and lake water were filtered with qualitative filter paper, and then separated by a centrifuge at 12000rpm. The concentration of CXT is 5.0×10 ^-6 mol/L water (1.0×10 ^-2 mol/LTris-HCl, 1.2×10 ^-3 mol/LBrij35, pH=8.0) solution, add HPB aqueous solution, and the final concentrations are respectively 5.00, 15.0, 20.0 and 25.0 μM. With excitation at 340 nm, the fluorescence emission intensity at 444 nm was recorded. By comparing with the quantitative standard curve, the actual detection concentration of HPB was obtained, and the recovery rate was calculated. Good experimental results were obtained, and the recovery rate was between 99.4-101.8%. The results show that it can be applied to the detection of HPB in actual environmental water samples.

Claims (2)

1. pair quaternized pyridinium cationic surfactants carries out the method for fluoroscopic examination, it is characterized in that used fluorescent reagent forms stable compound for fluorescer CXT, CXT and RPB, causes CXT fluorescent quenching;

The structural formula of quaternized pyridinium cationic surfactants is

R=C _nh _2n+1, or C _nh _2n+1nCOCH ₂, n=8-18; X ^-=Cl ^-, Br ^-, I ^-.

2. pair quaternized pyridinium cationic surfactants carries out the application of method in Environmental Water sample detection of fluoroscopic examination, with it is characterized in that the fluorescence selectivity of fluorescer CXT by RPB quencher;

The structural formula of quaternized pyridinium cationic surfactants is

R=C _nh _2n+1, or C _nh _2n+1nCOCH ₂, n=8-18; X ^-=Cl ^-, Br ^-, I ^-.