Chemiluminescent system based on PMS-luminol and detection method of triphenyl phosphate

Abstract

The present invention discloses a chemiluminescent system based on PMS-luminol and a detection method for triphenyl phosphate, which solves the technical problem that there is still no effective detection method for TPHP in the prior art. The chemiluminescent system based on PMS-luminol includes a first component and a second component, wherein the first component includes a first mixed solution after ultraviolet light irradiation, the first mixed solution includes PMS and a solution of a test object; the second component includes a second mixed solution, the second mixed solution includes luminol and a buffer solution; wherein the test object can weaken the chemiluminescent signal. The present invention uses PMS to generate SO4 while generating OH. ·‑ , increasing the types of active oxygen free radicals; oxidizing PMS with ultraviolet light effectively promoted ·OH and SO4 ·‑ The generation of luminol accelerates the consumption of active oxygen free radicals in the system, thereby reducing the active oxygen free radicals participating in luminol chemiluminescence, and ultimately causing the chemiluminescence system to exhibit a greater luminescence inhibition effect.

Description

Technical Field

[0001] The present invention relates to the technical field of chemiluminescence, and in particular to a chemiluminescence system based on PMS-luminol and a detection method for triphenyl phosphate. Background Art

[0002] Organophosphorus flame retardants (OPFRs) have excellent thermal insulation and plasticizing effects. They are mainly used as additives in industrial and household consumer products such as plastics, fabrics, electronic products and building materials, and have been widely used worldwide. Triphenyl phosphate (TPHP) is an aromatic organophosphate containing three benzene rings. It is widely used as an external plasticizer in furniture, printed circuit boards, hydraulic oils, paints, coatings and nail polish. In addition, since the structure of TPHP does not contain covalent bonds, TPHP is easily broken and enters the environment. TPHP residues have been detected in the air, soil, water environment and organisms. Airborne TPHP is adsorbed on soil, making it one of the main OPFRs detected in soil. TPHP is biodegradable and does not accumulate permanently in the environment, but its continued release into the environment may pose a risk to organisms due to long-term human use.

[0003] Luminol, also known as luminol, has a chemical formula of C8H7N3O2. It can be oxidized by hydrogen peroxide under alkaline conditions to produce excited 3-aminophthalate ions (3-APA*). When 3-APA* releases energy and returns to the ground state, it produces chemiluminescence with a wavelength of 425nm. Therefore, the luminol-H2O2 system is one of the classic chemiluminescence systems. The current applications of the luminol-H2O2 system are mainly the following two:

[0004] First, under normal circumstances, the chemiluminescent reaction between luminol and hydrogen peroxide is very rapid in the presence of certain catalysts. The most commonly used catalyst is metal ions. Within a wide concentration range, the metal ion concentration is proportional to the luminescence intensity, so chemiluminescent analysis of certain metal ions can be performed. Therefore, using this reaction, organic compounds containing metal ions can be analyzed with high sensitivity.

[0005] Secondly, the inhibitory effect of organic compounds on the chemiluminescent reaction of luminol is used to determine organic compounds that have a quenching effect on the chemiluminescent reaction. If TPHP has a quenching effect on the chemiluminescent reaction of the luminol-H2O2 system, then quantitative detection of TPHP can be achieved in theory.

[0006] However, the applicant of the present application has found in practice that although TPHP has a quenching effect on the chemiluminescence reaction of the luminol-H2O2 system, when the luminol-H2O2 system is used to detect TPHP, the detection limit and linear range cannot meet the ideal requirements, resulting in that there is still no effective detection method for TPHP. Summary of the invention

[0007] The main purpose of the present invention is to provide a chemiluminescent system based on PMS-luminol and a detection method for triphenyl phosphate, so as to solve the technical problem that there is still no effective detection method for TPHP in the prior art.

[0008] In order to achieve the above object, the present invention first provides a chemiluminescence system based on PMS-luminol, and the technical scheme is as follows:

[0009] The chemiluminescent system based on PMS-luminol includes a first component and a second component, wherein the first component includes a first mixed solution after ultraviolet light irradiation, the first mixed solution includes PMS and a solution of an object to be tested; the second component includes a second mixed solution, the second mixed solution includes luminol and a buffer solution; wherein the object to be tested can weaken the chemiluminescent signal.

[0010] As a further improvement of the above-mentioned PMS-luminol-based chemiluminescence system, the ultraviolet lamp is an ultraviolet high-pressure mercury lamp with a power of 300-500W and a main wavelength of 365nm; the ultraviolet light irradiation time is 2-5min; and the distance between the ultraviolet light and the liquid surface of the first mixed liquid is 15-20cm.

[0011] As a further improvement of the above-mentioned chemiluminescent system based on PMS-luminol, the volume ratio of PMS to the analyte solution in the first mixed solution is 1:(7-12).

[0012] As a further improvement of the above-mentioned chemiluminescent system based on PMS-luminol, the concentration of PMS in the first mixed solution is 50-100 mmol / L.

[0013] As a further improvement of the above-mentioned PMS-luminol-based chemiluminescence system, the concentration of luminol in the second mixed solution is 40-50 μmol / L; the buffer solution is Na2CO3-NaHCO3 buffer solution; and the pH of the second mixed solution is 10-12.

[0014] As a further improvement of the above-mentioned PMS-luminol-based chemiluminescent system, the volume ratio of the first component to the second component is (1-3):1.

[0015] In order to achieve the above object, the present invention secondly provides a detection method for triphenyl phosphate, and the technical scheme is as follows:

[0016] The method for detecting triphenyl phosphate using the above-mentioned PMS-luminol-based chemiluminescence system comprises the following steps: preparing triphenyl phosphate, a solvent and PMS into a first mixed solution; irradiating the first mixed solution with an ultraviolet lamp to obtain a first component; preparing luminol and a buffer solution into a second mixed solution to obtain a second component; adding the second component into a luminescent container; adding the first component into the luminescent container; and then detecting the chemiluminescent signal.

[0017] As a further improvement of the above detection method, the first component is added by a peristaltic pump with a rotation speed of 40-80 rpm.

[0018] As a further improvement of the above detection method, the solvent is acetonitrile or acetonitrile aqueous solution.

[0019] As a further improvement of the above detection method, two lifting platforms are symmetrically arranged below the ultraviolet lamp, and the first mixed liquid is arranged between the two lifting platforms.

[0020] It has been verified that the present invention uses PMS with better oxidation performance than H2O2, and generates SO4 while generating OH. ·- , which increases the types of active oxygen free radicals and helps to improve the reaction efficiency between active oxygen free radicals and the analyte; on the other hand, further oxidation of PMS by ultraviolet light effectively promotes the generation of ·OH and SO4 ·- The generation of ·OH accelerates the reaction of the analyte (such as TPHP) with active oxygen free radicals, quickly consumes the active oxygen free radicals in the system, and reduces the 1 O2 and O2 ·- The conversion reduces the active oxygen free radicals involved in the luminol chemiluminescence, thereby reducing the 3-APA* generated by the oxidative decomposition of the luminol anion, and finally makes the chemiluminescence system show a greater luminescence inhibition effect, and the generated chemiluminescence signal is significantly weakened, thereby significantly improving the sensitivity of the test object. It can be seen that the present invention is simple and easy to implement, effectively solves the technical obstacles of TPHP difficult monitoring, and has the value of promotion and use.

[0021] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of the present invention are used to assist in understanding the present invention. The contents provided in the drawings and their related descriptions in the present invention can be used to explain the present invention, but do not constitute improper limitations on the present invention. In the drawings:

[0023] Figure 1 It is a structural schematic diagram of the ultraviolet lamp irradiation device.

[0024] Figure 2 These are the chemiluminescence signal test results of the relevant system when UV, luminol, PMS and TPHP are used as variables.

[0025] Figure 3 The chemiluminescence signal test results of the UV-TPHP-PMS-luminol system when pH is a variable.

[0026] Figure 4 The chemiluminescence signal test results of the UV-TPHP-PMS-luminol system when the peristaltic pump speed is a variable.

[0027] Figure 5 The chemiluminescence signal test results of the UV-TPHP-PMS-luminol system when the PMS concentration is a variable.

[0028] Figure 6 The chemiluminescence signal test results of the UV-TPHP-PMS-luminol system when the luminol concentration is a variable.

[0029] Figure 7 The chemiluminescence signal test results of the UV-TPHP-PMS-luminol system when the irradiation time is a variable.

[0030] Figure 8 OH and SO4 in the PMS-luminol system before and after UV irradiation ·- EPR characterization results.

[0031] Fig. 9 The PMS-luminol system before and after UV irradiation 1 EPR characterization results of O2.

[0032] Fig.10 is the O2 of the PMS-luminol system before and after UV irradiation ·- EPR characterization results.

[0033] Fig.11 Fluorescence spectra of the UV-PMS-luminol system (a) and the UV-TPHP-PMS-luminol system (b).

[0034] Fig.12 The chemiluminescence signal test results of the UV-TPHP-PMS-luminol system under different TPHP concentrations.

[0035] Fig.13 It is the linear fitting curve of TPHP concentration and chemiluminescence intensity of UV-TPHP-PMS-luminol system.

[0036] Fig.14 This is the selectivity test result of the UV-PMS-luminol system for the analyte.

[0037] Fig.15 This is the anti-interference test result of the UV-PMS-luminol system on the analyte. DETAILED DESCRIPTION

[0038] The present invention is described clearly and completely below in conjunction with the accompanying drawings. A person skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0039] The technical solutions and technical features provided in each part of the present invention, including the following description, may be combined with each other if there is no conflict.

[0040] In addition, the embodiments of the present invention involved in the following description are generally only a part of the embodiments of the present invention, rather than all the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0041] About the terms and units in the present invention: The terms "include", "have" and any variations thereof in the description and claims of the present invention and related parts are intended to cover non-exclusive inclusions.

[0042] The specific embodiment of the chemiluminescent system based on PMS-luminol of the present invention comprises a first component and a second component, wherein the first component comprises a first mixed solution after ultraviolet (UV) irradiation, the first mixed solution comprises PMS (peroxymonosulfate) and a solution of an analyte; the second component comprises a second mixed solution, the second mixed solution comprises luminol and a buffer solution; wherein the analyte can weaken the chemiluminescent signal.

[0043] The ultraviolet lamp is an ultraviolet high-pressure mercury lamp with a power of 300-500W and a main wavelength of 365nm. In specific implementation, the power of the ultraviolet lamp can be but is not limited to any one of 300W, 320W, 350W, 380W, 400W, 430W, 450W, 470W, and 500W.

[0044] The ultraviolet light irradiation time is 2-5 minutes. In specific implementation, the irradiation time can be, but is not limited to, any one of 2 minutes, 2.5 minutes, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes, and 5 minutes.

[0045] The distance between the ultraviolet light and the liquid surface of the first mixed liquid is 15-20 cm. In specific implementation, the distance can be, but is not limited to, any one of 15 cm, 16 cm, 17 cm, 18 cm, 19 cm, and 20 cm.

[0046] The volume ratio of PMS to the test solution in the first mixed solution is 1:(7-12). In specific implementation, the volume ratio can be, but is not limited to, any one of 1:7, 1:8, 1:9, 1:10, 1:11, and 1:12.

[0047] The concentration of PMS in the first mixed solution is 50-100mmol / L. In specific implementation, the concentration can be, but is not limited to, any one of 50mmol / L, 60mmol / L, 70mmol / L, 80mmol / L, 90mmol / L, and 100mmol / L.

[0048] The concentration of luminol in the second mixed solution is 40-50 μmol / L. In specific implementation, the concentration can be, but is not limited to, any one of 40 μmol / L, 42 μmol / L, 44 μmol / L, 46 μmol / L, 48 μmol / L, and 50 μmol / L.

[0049] The buffer is Na2CO3-NaHCO3 buffer.

[0050] The pH value of the second mixed liquid is 10-12. In specific implementation, the pH value can be, but is not limited to, any one of 10, 11, 11.2, 11.4, 11.6, 11.8, and 12.

[0051] The volume ratio of the first component to the second component is (1-3):1. In a specific implementation, the volume ratio can be, but is not limited to, any one of 1:1, 1.5:1, 2:1, 2.5:1, and 3:1.

[0052] The specific implementation method of the detection method of triphenyl phosphate (TPHP) of the present invention is to use the above-mentioned PMS-luminol-based chemiluminescence system to detect triphenyl phosphate, and the chemiluminescence signal is collected by the ultra-weak chemiluminescence instrument of BPCL. The detection process specifically includes the following steps:

[0053] (1) preparing a first mixed solution by mixing TPHP, a solvent and PMS;

[0054] (2) irradiating the first mixed solution with an ultraviolet lamp to obtain a first component;

[0055] Figure 1 FIG. 1 is a schematic diagram of the structure of the ultraviolet lamp irradiation device. Figure 1As shown, two lifting platforms are symmetrically arranged below the ultraviolet lamp, and the container containing the first mixed liquid is placed between the two lifting platforms. The cross-sectional diameter of the container is 24 mm, the model of the ultraviolet lamp is GGZ (Shanghai Jiguang Special Lighting Appliance Factory), and the distance H between the ultraviolet light and the liquid surface of the first mixed liquid is 18 cm.

[0056] (3) preparing a second mixed solution with luminol and a buffer solution to obtain a second component;

[0057] (4) adding the second component into the luminescent dish of the ultra-weak chemiluminescence instrument and then closing the light window;

[0058] (4) using a peristaltic pump to add the first component to the luminescent dish containing the second component;

[0059] (5) Then the BPCL software of the ultra-weak chemiluminescence instrument starts to detect the chemiluminescence signal. The chemiluminescence signal acquisition interval is 0.1 s, and the negative high voltage is set to 800 V.

[0060] The peristaltic pump has a rotation speed of 40-80 rpm. In specific implementation, the rotation speed of the peristaltic pump can be, but is not limited to, any one of 40 rpm, 50 rpm, 60 rpm, 70 rpm, and 80 rpm.

[0061] The solvent is acetonitrile or acetonitrile aqueous solution. One use method is: firstly, acetonitrile is used to dissolve TPHP to obtain a stock solution, and then according to the required concentration, the stock solution is taken at any time and adjusted to the required concentration with acetonitrile aqueous solution.

[0062] The beneficial effects of the present invention are described below through specific experimental data.

[0063] In the following experiment: the power of the UV lamp is 400W, and the distance between the UV light and the liquid surface of the first mixed solution is 18cm; the volume ratio of PMS and the test solution in the first mixed solution is 1:9; the volume ratio of the first component to the second component is 2:1 (specifically 100μL luminol solution, 100μL buffer solution and 400μL first mixed solution); the concentration of TPHP in the stock solution is 20000ng / L, and each dilution uses a 10% acetonitrile aqueous solution.

[0064] Figure 2The chemiluminescent signal test results of the relevant system when UV, luminol, PMS and TPHP are used as variables. Among them, curve (a) belongs to the PMS-luminol system, that is, UV and TPHP are not used; curve (b) belongs to the TPHP-PMS-luminol system, that is, UV is not used; curve (c) belongs to the UV-PMS-luminol system, that is, TPHP is not used; curve (d) belongs to the UV-TPHP-PMS-luminol system; curve (e) belongs to the UV-TPHP-PMS system, that is, luminol is not used; curve (f) belongs to the UV-TPHP-luminol system, that is, PMS is not used.

[0065] from Figure 2 It can be seen that by comparing curves (a) and (b), it can be found that in the absence of UV, the introduction of TPHP will weaken the chemiluminescent signal of the PMS-luminol system by about 50%, while the introduction of TPHP can only weaken the chemiluminescent signal of the H2O2-luminol system by about 40%, which shows that PMS plays an important role in the detection of TPHP. By comparing curves (c) and (d), it can be found that when TPHP is added to the UV-PMS-luminol system, the chemiluminescent signal is reduced by about 85%, which shows that the UV-PMS-luminol system can detect TPHP with high sensitivity. By comparing curves (d) and (f), it can be found that PMS plays an important role in the system. The introduction of PMS increases the luminescence intensity of the UV-TPHP-PMS-luminol system by more than 300 times. By comparing curves (d) and (e), it can also be found that the presence of luminol is also important for the detection of TPHP. The above comparison shows that the UV-TPHP-PMS-luminol system combining PMS and UV is the best means for TPHP detection.

[0066] Figure 3 The chemiluminescence signal test results of the UV-TPHP-PMS-luminol system when pH is a variable. Figure 4 The chemiluminescence signal test results of the UV-TPHP-PMS-luminol system when the peristaltic pump speed is a variable. Figure 5 The chemiluminescence signal test results of the UV-TPHP-PMS-luminol system when the PMS concentration is a variable. Figure 6 The chemiluminescence signal test results of the UV-TPHP-PMS-luminol system when the luminol concentration is a variable. Figure 7 The chemiluminescence signal test results of the UV-TPHP-PMS-luminol system when the irradiation time is a variable.

[0067] like Figure 3-7As shown, the optimal conditions for detecting TPHP are: PMS concentration of 50 mmol / L, luminol concentration of 40 μmol / L, pH value of 11, peristaltic pump speed of 60 rpm and irradiation time of 2 min.

[0068] Figure 8 OH and SO4 in the PMS-luminol system before and after UV irradiation ·- EPR characterization results. Fig. 9 The PMS-luminol system before and after UV irradiation 1 EPR characterization results of O2. Fig.10 is the O2 of the PMS-luminol system before and after UV irradiation ·- EPR characterization results. Among them, ★ represents DMPO capturing ·OH, ▲ represents DMPO capturing SO4 ·- ;TEMP is 1 O2 capture agent; NBT is O2 ·- The capture agent. EPR is electron paramagnetic resonance, and the equipment model is BrukerEMXPLUS (Bruker, Germany).

[0069] from Figure 8-10 It can be seen that without UV (0min) assistance, OH and SO4 in the chemiluminescence system ·- The characteristic peak of SO4 is not obvious, while the characteristic peak of SO4 is not obvious when UV irradiated for 2 minutes. ·- 、·OH、 1 O2 and O2 ·- The signals of SO4 ·- , OH and 1 The signal of O2 is weakened, but O2 ·- The signal is still strong, which means that O2 ·- The contribution of active oxygen free radicals and TPHP reactions is relatively small.

[0070] Fig.11 Fluorescence spectra of the UV-PMS-luminol system (a) and the UV-TPHP-PMS-luminol system (b), the equipment model is F-7000 (Hitachi Scientific Instruments Co., Ltd.).

[0071] from Fig.11 It can be seen that the peak positions of curve (a) and curve (b) are the same, indicating that the introduction of TPHP does not change the luminophore, that is, the chemiluminescence signal of the system is caused by luminol.

[0072] Fig.12The chemiluminescence signal test results of the UV-TPHP-PMS-luminol system under different TPHP concentrations. Fig.13 It is the linear fitting curve of TPHP concentration and chemiluminescence intensity of UV-TPHP-PMS-luminol system.

[0073] like Figure 12-13 As shown in the figure, the chemiluminescence intensity of the UV-TPHP-PMS-luminol system gradually weakened with the increase of TPHP concentration, and there was a good linear relationship in the range of 80-1000 ng / L: I = -23.961C + 30067.683 (R 2 =0.991), where I is the chemiluminescent signal intensity and C is the TPHP concentration. The calculated detection limit is 42.3 ng / L.

[0074] Fig.14 The selectivity test results of the UV-PMS-luminol system for the analytes were 1000 ng / L.

[0075] like Fig.14 As shown, the addition of TPHP has a significant inhibitory effect on the chemiluminescence of the UV-PMS-luminol system, while other analytes have little effect on the chemiluminescence signal of the UV-PMS-luminol system.

[0076] Fig.15 This is the anti-interference test result of the UV-PMS-luminol system on the analyte.

[0077] like Fig.15 As shown, when 1000 ng / L TPHP coexists with anti-interference ions, the system has good anti-interference ability to 50 times of sulfate, magnesium, sodium and calcium ions, 30 times of potassium, chloride, carbonate, nitrate and phosphate, and 20 times of bicarbonate.

[0078] For the analysis of environmental samples, water samples were extracted from the lake water of Southwest Jiaotong University and filtered through a 0.45 μm filter membrane to remove impurities in the water. Soil samples were taken from the soil of the lawn on campus and dried, ground, and sieved (using a sieve with a pore size of 2 mm) before use.

[0079] For the spiked test of soil samples, specifically: add the soil sample and TPHP solution of different concentrations into a centrifuge tube, vortex for 10 minutes to fully mix it, and then take the supernatant for detection after solid-liquid separation (centrifugation at 4000r / min for 15 minutes).

[0080] The test results of the spiked experiment of the UV-PMS-luminol system are shown in Table 1. As can be seen from Table 1, no TPHP was detected in the unspiked original water samples and soil samples; after spiked with TPHP solutions of concentrations of 700ng / L, 900ng / L and 1000ng / L, the recovery rates of the detection were 95.06-105.9%, and the relative standard deviations (RSDs) were all less than 3.33%. It can be seen that the UV-PMS-luminol system of the present invention can be used to analyze TPHP in environmental samples to a certain extent.

[0081] Table 1

[0082]

[0083] The above is a description of the relevant contents of the present invention. A person skilled in the art will be able to implement the present invention based on these descriptions. Based on the above contents of the present invention, all other embodiments obtained by a person skilled in the art without creative work shall fall within the scope of protection of the present invention.

Claims

1. A chemiluminescent system based on PMS-luminol, characterized in that: It comprises a first component and a second component, wherein: The first component includes a first mixed solution after ultraviolet light irradiation, and the first mixed solution includes PMS and a solution of a substance to be tested; The second component includes a second mixed solution, and the second mixed solution includes luminol and a buffer solution; Wherein, the analyte can weaken the chemiluminescent signal; the analyte is triphenyl phosphate.

2. The chemiluminescent system based on PMS-luminol according to claim 1, characterized in that: The ultraviolet lamp providing ultraviolet light is an ultraviolet high-pressure mercury lamp with a power of 300-500W and a main wavelength of 365nm; the ultraviolet light irradiation time is 2-5min; and the distance between the ultraviolet light and the liquid surface of the first mixed liquid is 15-20cm.

3. The chemiluminescent system based on PMS-luminol according to claim 1, characterized in that: The volume ratio of PMS to the test substance solution in the first mixed solution is 1:(7-12).

4. The chemiluminescent system based on PMS-luminol according to claim 1, characterized in that: The concentration of PMS in the first mixed solution is 50-100 mmol / L.

5. The chemiluminescent system based on PMS-luminol according to claim 1, characterized in that: The concentration of luminol in the second mixed solution is 40-50 μmol / L; the buffer solution is Na2CO3-NaHCO3 buffer solution; and the pH of the second mixed solution is 10-12.

6. The chemiluminescent system based on PMS-luminol according to claim 1, characterized in that: The volume ratio of the first component to the second component is (1-3):

1.

7. A method for detecting triphenyl phosphate using the PMS-luminol based chemiluminescence system according to any one of claims 1 to 6, comprising the following steps: triphenyl phosphate, solvent and PMS are prepared into a first mixed solution; The first mixed solution is irradiated with an ultraviolet lamp to obtain a first component; The luminol and the buffer solution are prepared into a second mixed solution, so as to obtain a second component; adding the second component to the light-emitting container; adding a first component to a light-emitting container; The chemiluminescent signal is then detected.

8. The detection method according to claim 7, characterized in that: The first component is added by a peristaltic pump, and the speed of the peristaltic pump is 40-80 rpm.

9. The detection method according to claim 7, characterized in that: The solvent is acetonitrile or acetonitrile aqueous solution.

10. The detection method according to claim 7, characterized in that: Two lifting platforms are symmetrically arranged below the ultraviolet lamp, and the first mixed liquid is arranged between the two lifting platforms.

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