Detection method and materials for tricresyl phosphate concentration in water

Abstract

The present invention discloses a detection method and detection material for the concentration of tricresyl phosphate in a water body, and solves the problem that tricresyl phosphate is difficult to detect in the prior art. The detection method for the concentration of tricresyl phosphate in a water body, comprising the following steps: adding 9-(2,2-dicyanovinyl) julodidine solution to pure water to obtain a first mixed solution, and then testing to obtain a first fluorescence intensity of the first mixed solution; adding 9-(2,2-dicyanovinyl) julodidine solution to a water body to be tested containing tricresyl phosphate to obtain a second mixed solution, and then testing to obtain a second fluorescence intensity of the second mixed solution; substituting the first fluorescence intensity and the second fluorescence intensity into a linear equation with the concentration of tricresyl phosphate, the concentration value converted is the concentration of tricresyl phosphate in the water body to be tested. The detection material for the concentration of tricresyl phosphate in a water body, including a 9-(2,2-dicyanovinyl) julodidine solution with methanol or ethanol as a solubilizing agent.

Description

Technical Field

[0001] The present invention relates to the technical field of detecting the concentration of organophosphorus flame retardants in water, and in particular to a method and material for detecting the concentration of tricresyl phosphate in water. Background Art

[0002] In recent years, organophosphorus flame retardants (OPFRs) have been widely used in home decoration, building materials, textiles, electronics, chemicals, and papermaking due to their excellent physicochemical properties and low cost. However, because OPFRs are added to materials through physical mixing, they are more likely to be released into the environment through volatilization, dissolution, leaching, and abrasion. OPFRs can accumulate in aquatic organisms and exhibit cardiotoxicity, neurotoxicity, reproductive toxicity, and carcinogenicity, posing a threat to human health and the environment.

[0003] Tricresyl phosphate (TCP) is a typical example of an aromatic OPFR, primarily added to hydraulic, engine, and lubricating oils. Ecological risk assessments indicate that TCP has a high bioconcentration factor (BCF), posing a moderate risk to organisms. Therefore, the presence of TCP poses irreversible hazards to humans and the ecological environment. Furthermore, TCP has been detected in drinking water, rivers, and lakes. Therefore, developing methods for detecting TCP in aquatic environments is beneficial to environmental development.

[0004] Currently, traditional methods for detecting OPFRs primarily include gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, electrochemical methods, gas chromatography with nitrogen-phosphorus detection, and electrospray ionization mass spectrometry. These methods are inherently limited by high cost, long analysis cycles, difficult pretreatment processes, and limited sensitivity or selectivity, making them unsuitable for detecting TCP. Consequently, there is currently no simple, cost-effective, rapid, sensitive, and reliable method for detecting TCP. Summary of the Invention

[0005] The main purpose of the present invention is to provide a method and material for detecting the concentration of tricresyl phosphate in water, so as to solve the problem that tricresyl phosphate is difficult to detect in the prior art.

[0006] In order to achieve the above object, according to a first aspect of the present invention, a method for detecting the concentration of tricresyl phosphate in water is provided, and the technical solution is as follows:

[0007] The method for detecting the concentration of tricresyl phosphate in water comprises the following steps:

[0008] Adding a 9-(2,2-dicyanovinyl)julodidine solution to pure water to obtain a first mixed solution, and then testing to obtain a first fluorescence intensity of the first mixed solution;

[0009] adding a 9-(2,2-dicyrovinyl)julodidine solution to a test water body containing tricresyl phosphate to obtain a second mixed solution, and then testing to obtain a second fluorescence intensity of the second mixed solution;

[0010] Substitute the first fluorescence intensity and the second fluorescence intensity into the linear equation of the tricresyl phosphate concentration, and the converted concentration value is the tricresyl phosphate concentration in the water body to be tested.

[0011] As a further improvement to the first aspect of the present invention, the excitation wavelength during fluorescence testing is 440 nm; when the concentration of tricresyl phosphate is 0.02 to 1.2 mg / L, the linear equation is y = -0.11652 + 0.31077x; when the concentration of tricresyl phosphate is 1.6 to 8 mg / L, the linear equation is y = -31.18616 + 20.92938x; wherein x is the concentration of tricresyl phosphate, y is F1 / F0-1, F0 is the first fluorescence intensity, and F1 is the second fluorescence intensity.

[0012] As a further improvement of the first aspect of the present invention, the dissolving agent of the 9-(2,2-dicyanovinyl)julodidine solution is methanol or ethanol that can dissolve tricresyl phosphate.

[0013] As a further improvement of the first aspect of the present invention, the volume ratio of the dissolving agent to the water body to be tested is 2:13.

[0014] As a further improvement of the first aspect of the present invention, the first mixed solution and the second mixed solution are subjected to fluorescence testing after incubation for 5 to 7 minutes.

[0015] As a further improvement of the first aspect of the present invention, the concentration of 9-(2,2-dicyanovinyl)julodine in the first mixture and the second mixed solution is 20 μM.

[0016] As a further improvement of the first aspect of the present invention, the pH of the first mixed solution and the second mixed solution is adjusted to 6-7 using a buffer solution.

[0017] As a further improvement of the first aspect of the present invention, the first mixed solution and the second mixed solution are processed using a vortex machine.

[0018] As a further improvement of the first aspect of the present invention, the water body to be tested also contains any several of tricresyl phosphate, trioctyl phosphate, triphenyl phosphate, tributyl phosphate, tris(2-chloroisopropyl) phosphate, isocarbophos, dimethoate, monocrotophos, trichlorfon, aluminum ions, barium ions, trivalent iron ions, calcium ions, cadmium ions, hexavalent cobalt ions, trivalent chromium ions, copper ions, divalent iron ions, potassium ions, magnesium ions, manganese ions, sodium ions, lead ions, zinc ions, fluoride ions, chloride ions, bromide ions, iodide ions, nitrite ions, bicarbonate ions, carbonate ions, sulfite ions, sulfate ions, phosphate ions, hydrogen phosphate ions, and dihydrogen phosphate ions.

[0019] In order to achieve the above object, according to a second aspect of the present invention, a method for detecting the concentration of tricresyl phosphate in water is provided, and the technical solution is as follows:

[0020] The detection material for the concentration of tricresyl phosphate in water includes a 9-(2,2-dicyanovinyl)julodidine solution with methanol or ethanol as a solvent.

[0021] As a further improvement of the second aspect of the present invention, the concentration of the 9-(2,2-dicyanovinyl)julodidine solution is 150 μM.

[0022] The method and material for detecting the concentration of tricresyl phosphate in water bodies of the present invention creatively propose to use 9-(2,2-dicyanovinyl)jurodine to perform fluorescence detection of tricresyl phosphate. The method not only has the advantages of low cost, easy operation and rapidity of fluorescence detection itself, but also has been verified in practice to have the advantages of low detection limit, high sensitivity, strong specific recognition ability, wide linear range, strong anti-interference ability, etc. Therefore, the present invention is expected to become a standard method for detecting the concentration of tricresyl phosphate in water bodies and has extremely strong practicality.

[0023] The present invention will be further described below with reference to 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 practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings that constitute part of this invention are intended to assist in understanding the invention. The contents provided in the drawings and their related descriptions in the present invention may be used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0025] Figure 1 The UV-visible absorption and fluorescence spectra of DCVJ solution prepared in methanol.

[0026] Figure 2 The fluorescence enhancement efficiency of TCP in DCVJ solution was tested as a function of the solvent.

[0027] Figure 3 The fluorescence enhancement efficiency of TCP tested in DCVJ solution and the change of fluorescence intensity with DCVJ concentration are shown.

[0028] Figure 4 The fluorescence enhancement efficiency of TCP in DCVJ solution changes with pH.

[0029] Figure 5 The graph shows the change of fluorescence enhancement efficiency of TCP in DCVJ solution as a function of incubation time.

[0030] Figure 6 This is a graph showing the changes in fluorescence enhancement efficiency when testing different pollutants in DCVJ solution.

[0031] Figure 7 The fluorescence intensity of the first mixture and the second mixture changes with the cation (M n+ ) change diagram.

[0032] Figure 8 The fluorescence intensity of the first mixture and the second mixture changes with the anion (L n- ) change diagram.

[0033] Figure 9 Fluorescence spectra of different concentrations of TCP were tested for DCVJ solution.

[0034] Figure 10 The graph showing the fluorescence enhancement efficiency of TCP in DCVJ solution as a function of TCP concentration.

[0035] Figure 11 The linear relationship between the low concentration of TCP and the fluorescence enhancement efficiency obtained by fitting.

[0036] Figure 12 The linear relationship diagram between high concentration TCP concentration and fluorescence enhancement efficiency obtained by fitting. DETAILED DESCRIPTION

[0037] The present invention is described clearly and completely below with reference to 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 with reference to the accompanying drawings, it should be noted that:

[0038] The technical solutions and technical features provided in each part of the present invention, including the following description, may be combined with each other unless there is any conflict.

[0039] In addition, the embodiments of the present invention described below are generally only part of the embodiments of the present invention, rather than all of the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making any creative efforts should fall within the scope of protection of the present invention.

[0040] Regarding 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 the related parts are intended to cover non-exclusive inclusions.

[0041] The specific embodiment of the detection material for the concentration of tricresyl phosphate in water of the present invention comprises a 9-(2,2-dicyanovinyl)juridine (hereinafter referred to as DCVJ) solution using methanol or ethanol as a solvent.

[0042] Figure 1 The UV-visible absorption spectrum and fluorescence spectrum of DCVJ solution prepared in methanol. During the test, the volume of DCVJ solution was 200μL and the concentration was 150μM. During the test, the DCVJ solution was placed in a cuvette and then diluted to 1500mL with ultrapure water (the concentration of DCVJ was 20μM at this time), and then the fluorescence intensity and absorbance were tested. Figure 1 As shown in FIG, under an excitation wavelength of 440 nm, the fluorescence emission peak is concentrated at 510 nm. Therefore, it is preferred that the excitation wavelength of the fluorescence test be set to 440 nm.

[0043] The specific embodiment of the method for detecting the concentration of tricresyl phosphate in water of the present invention comprises the following steps:

[0044] Adding a 9-(2,2-dicyanovinyl)julodidine solution to pure water to obtain a first mixed solution, and then testing to obtain a first fluorescence intensity of the first mixed solution;

[0045] adding a 9-(2,2-dicyrovinyl)julodidine solution to a test water body containing tricresyl phosphate to obtain a second mixed solution, and then testing to obtain a second fluorescence intensity of the second mixed solution;

[0046] Substitute the first fluorescence intensity and the second fluorescence intensity into the linear equation of the tricresyl phosphate concentration, and the converted concentration value is the tricresyl phosphate concentration in the water body to be tested.

[0047] In order to improve the uniformity of the first mixed solution and the second mixed solution, the first mixed solution and the second mixed solution were treated with a vortex machine for 10 seconds and then subjected to fluorescence treatment.

[0048] The process of obtaining the linear equation is as follows:

[0049] First, to obtain optimal test conditions, the effects of solvent, DCVJ concentration, pH, and incubation time on fluorescence test results were investigated as follows:

[0050] Figure 2 This graph shows the fluorescence enhancement efficiency of TCP in DCVJ solution as a function of the solvent. Incubation and pH adjustment were not performed during the test. The fluorescence intensity (F0) of a first mixture consisting of a DCVJ solution (150 μL, 200 μM concentration) without TCP, 50 μL of the solvent, and 1300 μL of pure water was measured. The fluorescence intensity (F1) of a second mixture consisting of a DCVJ solution (150 μL, 200 μM concentration) with TCP added, a TCP solution (50 μL, 20 mg / L concentration), and 1300 μL of pure water was measured. The vertical axis, F1 / F0-1, represents the fluorescence enhancement efficiency, indicating the fluorescence enhancement effect of TCP on DCVJ. The same applies below.

[0051] Figure 3 The fluorescence enhancement efficiency of TCP in DCVJ solution and the change of fluorescence intensity with DCVJ concentration are shown. Figure 2 The difference in the test method used is that the variable is DCVJ solution with concentrations of 26.7 μM, 66.7 μM, 133.3 μM, 200 μM and 266.7 μM.

[0052] Figure 4 The fluorescence enhancement efficiency of TCP in DCVJ solution changes with pH. Figure 2 The difference between the test methods used is that the variable is pH, and PBS buffer is used to adjust the pH of the first mixture and the second mixture to 5, 6, 7, 8, 9 and 10 respectively.

[0053] Figure 5 The fluorescence enhancement efficiency of TCP in DCVJ solution changes with incubation time. Figure 2 The difference in the test methods used is that the variable is the incubation time, and the incubation times for the first mixture and the second mixture are 3 minutes, 5 minutes, 7 minutes, 10 minutes, 30 minutes, 45 minutes and 60 minutes, respectively.

[0054] like Figure 2 As shown in , when the solvent is methanol or ethanol, the fluorescence enhancement efficiency is the highest, and methanol is the most preferred solvent. Figure 3 As shown in FIG, as the concentration of DCVJ increases, the fluorescence enhancement efficiency increases, but there is an inflection point at a DCVJ solution concentration of 200 μM, and the higher the concentration of the DCVJ solution, the greater the error and the higher the cost. Therefore, it is preferred that the concentration of the DCVJ solution be 200 μM, that is, the concentration of DCVJ in the second mixture be 20 μM. Figure 4 As shown in the figure, the optimal test pH is 6-7, which is close to the pH of water in real life. This means that in actual application, it is no longer necessary to deliberately adjust the pH, which can effectively improve the detection speed. Figure 5 As shown, the fluorescence enhancement efficiency is best when the incubation time is only 5-7 minutes. In summary, the test conditions used in the following experiments to test the linear equation are: methanol as the solvent, DCVJ solution concentration of 200 μM, no pH adjustment, incubation time of 7 minutes, and the amount of solvent used is 200 μL.

[0055] As can be seen from the above test conditions, the test conditions of the present invention are mild, so the first fluorescence intensity is generally a fixed value. In actual application, the second fluorescence intensity of the water to be tested is directly tested, and then the TCP concentration in the water to be tested can be converted through a linear equation.

[0056] In practical applications, to simplify the process, it is preferred to directly use 200 μL of a 150 μM DCVJ solution (containing 50 μL of methanol in a TCP solution). That is, F0 is the fluorescence intensity of the first mixture consisting of a 200 μL DCVJ solution (150 μM concentration) and 1300 μL of pure water, and F1 is the fluorescence intensity of the first mixture consisting of a 200 μL DCVJ solution (150 μM concentration) and 1300 μL of the water to be tested.

[0057] Secondly, since there are many pollutants and foreign ions in the water, in order to prove the practicality of the DCVJ detection of TCP of the present invention, specific recognition test and anti-interference test were also carried out, as follows:

[0058] Figure 6 Figure 2 shows the fluorescence enhancement efficiency changes of the DCVJ solution when testing different pollutants. Each pollutant was prepared in methanol to a 50 μL volume and a 20 mg / L concentration. In addition to TCP, the pollutants included tricresyl phosphate, trioctyl phosphate, triphenyl phosphate, tributyl phosphate, tris(2-chloroisopropyl) phosphate, isocarbophos, dimethoate, monocrotophos, and trichlorfon.

[0059] Figure 7 The fluorescence intensity of the first mixture and the second mixture changes with the cation (M n+ ) change diagram. Figure 8 The fluorescence intensity of the first mixture and the second mixture changes with the anion (L n-) change graph. Wherein, the blank is the fluorescence intensity of the second mixture (high) and the fluorescence intensity of the first mixture (low). The added miscellaneous ions include aluminum ions, barium ions, ferric ions, calcium ions, cadmium ions, hexavalent cobalt ions, chromium ions, copper ions, ferrous ions, potassium ions, magnesium ions, manganese ions, sodium ions, lead ions, zinc ions, fluoride ions, chloride ions, bromide ions, iodide ions, nitrite ions, bicarbonate ions, carbonate ions, sulfite ions, sulfate ions, phosphate ions, hydrogen phosphate ions, and dihydrogen phosphate ions. After the addition of miscellaneous ions, the concentrations of aluminum ions, ferric ions, ferrous ions, lead ions, fluoride ions, chloride ions, carbonate ions, and sulfate ions were 18 μM, and the concentrations of the remaining miscellaneous ions were 180 μM. Figure 7 In the example, the first mixture and the second mixture after adding cations are represented by DCVJ+M n+ and DCVJ+M n+ +TCP, Figure 8 In the example, the first mixture and the second mixture after adding anions are represented by DCVJ+L n- and DCVJ+L n- +TCP.

[0060] like Figure 6 As shown in Figure 2, when the pollutant is TCP, the fluorescence enhancement efficiency is much higher than that of other pollutants. Figure 7-8 As shown, the effect of higher concentrations of impurity ions on the fluorescence enhancement of TCP is negligible, indicating that the detection method of the present invention has good anti-interference performance. Therefore, even if the actual water contains the above-mentioned pollutants and impurity ions, the detection method of the present invention can also achieve TCP concentration detection.

[0061] Finally, the linear equation is obtained by testing under the above optimal test conditions, as follows:

[0062] Figure 9 Fluorescence spectra of different concentrations of TCP were tested for DCVJ solution. Figure 10 The graph showing the fluorescence enhancement efficiency of TCP in DCVJ solution as a function of TCP concentration. Figure 11 The figure is a linear relationship diagram between the low concentration of TCP and the fluorescence enhancement efficiency obtained by fitting (the TCP concentration in the second mixture is 0.02-1.2 mg / L). Figure 12 The figure is a linear relationship diagram between the high concentration of TCP and the fluorescence enhancement efficiency obtained by fitting (the TCP concentration in the second mixture is 1.6-8 mg / L).

[0063] like Figure 9-10 As shown in Figure 2, there are two linear relationships between TCP concentration and fluorescence enhancement efficiency. Figure 11-12As shown in the figure, when the TCP concentration is 0.02-1.2 mg / L, the linear equation is y=-0.11652+0.31077x, R 2 is 0.9514; when the TCP concentration is 1.6-8 mg / L, the linear equation is y=-31.18616+20.92938x, R 2 The fluorescence intensity (F0) of the first mixture consisting of a DCVJ solution (150 μL, 200 μM concentration) without TCP added, 50 μL of a dissolving agent, and 1300 μL of pure water was measured. The fluorescence intensity (F1) of the second mixture consisting of a DCVJ solution (150 μL, 200 μM concentration) with TCP added, a TCP solution (50 μL, 20 mg / L concentration), and 1300 μL of pure water was then measured.

[0064] To verify the practicality of the present invention, the linear relationship described above was used to test actual environmental samples. Since the selected Fuhe River water and tap water samples contained virtually no TCP and their contents were below the detection limit, spiked water samples were tested as follows: Particulate matter was removed from the tap and Fuhe River water samples. The fluorescence intensity (F0) of a first mixture consisting of 150 μL of DCVJ solution, 50 μL of methanol, and 1300 μL of pure water without TCP was first measured. The fluorescence intensity (F1) of a second mixture consisting of 150 μL of TCP-added DCVJ solution, 50 μL of TCP solution, and 1300 μL of tap water or Fuhe River water was then measured. The TCP spike concentration in the second mixture was either 0.67 mg / L or 1 mg / L, and the DCVJ concentration in the first and second mixtures was 20 μM. The resulting F0 and F1 values ​​were then substituted into the linear equations described above to calculate the TCP concentration. The specific test results are shown in Table 1.

[0065] Table 1

[0066]

[0067] As shown in Table 1, the recoveries in the spiked test ranged from 95.3% to 100.9%, approaching 100%, and the relative standard deviation was less than 3.96%. This demonstrates that the detection method of the present invention has excellent accuracy and reproducibility and holds great potential in the field of environmental analysis. Compared with electrochemical and chromatographic methods, this method offers advantages such as high sensitivity, strong anti-interference capabilities, and simple operation, making it an innovative method for detecting TCP.

[0068] When the water to be tested is industrial wastewater related to hydraulic oil, engine oil and lubricating oil, the TCP content is higher than the detection limit. At this time, the calculated concentration is the TCP concentration in the water to be tested.

[0069] In the present invention, the pH value of the solution was measured using a pHS-3C pH meter (Chengdu Century Ark Company, China); the UV-visible absorption spectrum was measured using a USB-4000 UV-vis spectrometer (Ocean Optics, USA); and the fluorescence emission spectrum was measured on an FLS1000-stm steady-state / transient fluorescence spectrometer (Edinburgh, UK), with the excitation slit width and emission slit width being 2 nm and 1.5 nm, respectively.

[0070] The above describes the relevant contents of the present invention. Based on this description, a person skilled in the art will be able to implement the present invention. Based on the above contents of the present invention, all other embodiments obtained by a person skilled in the art without making any creative efforts should fall within the scope of protection of the present invention.

Claims

1. A method for detecting the concentration of tricresyl phosphate in water, characterized in that: The following steps are involved: Adding a 9-(2,2-dicyanovinyl)julodidine solution to pure water to obtain a first mixed solution, and then testing to obtain a first fluorescence intensity of the first mixed solution; adding a 9-(2,2-dicyrovinyl)julodidine solution to a test water body containing tricresyl phosphate to obtain a second mixed solution, and then testing to obtain a second fluorescence intensity of the second mixed solution; Substitute the first fluorescence intensity and the second fluorescence intensity into the linear equation of the tricresyl phosphate concentration, and the converted concentration value is the tricresyl phosphate concentration in the water body to be tested.

2. The method for detecting tricresyl phosphate concentration in water as claimed in claim 1, wherein: The excitation wavelength during the fluorescence test was 440 nm. When the concentration of tricresyl phosphate was 0.02 to 1.2 mg / L, the linear equation was y = -0.11652 + 0.31077x. When the concentration of tricresyl phosphate was 1.6 to 8 mg / L, the linear equation was y = -31.18616 + 20.92938x. Here, x was the concentration of tricresyl phosphate, y was F1 / F0-1, F0 was the first fluorescence intensity, and F1 was the second fluorescence intensity.

3. The method for detecting tricresyl phosphate concentration in water as claimed in claim 2, wherein: The dissolving agent of the 9-(2,2-dicyanovinyl)julodidine solution is methanol or ethanol which can dissolve tricresyl phosphate.

4. The method for detecting the concentration of tricresyl phosphate in water as claimed in claim 3, wherein: The volume ratio of the solvent to pure water or the water to be tested is 2:

13.

5. The method for detecting the concentration of tricresyl phosphate in water as claimed in claim 2, wherein: The first mixed solution and the second mixed solution are incubated for 5 to 7 minutes before fluorescence testing.

6. The method for detecting the concentration of tricresyl phosphate in water as claimed in claim 2, wherein: The concentration of 9-(2,2-dicyanovinyl)julodine in the first mixed solution and the second mixed solution is 20 μM.

7. The method for detecting the concentration of tricresyl phosphate in water as claimed in claim 2, wherein: The method further includes adjusting the pH of the first mixed solution and the second mixed solution to 6-7 using a buffer solution.

8. The method for detecting the concentration of tricresyl phosphate in water as claimed in claim 2, wherein: The method also includes using a vortex machine to process the first mixed solution and the second mixed solution.

9. The method for detecting the concentration of tricresyl phosphate in water as claimed in claim 1, wherein: The water body to be tested also contains any of tricresyl phosphate, trioctyl phosphate, triphenyl phosphate, tributyl phosphate, tris(2-chloroisopropyl) phosphate, isocarbophos, dimethoate, monocrotophos, trichlorfon, aluminum ions, barium ions, trivalent iron ions, calcium ions, cadmium ions, hexavalent cobalt ions, trivalent chromium ions, copper ions, divalent iron ions, potassium ions, magnesium ions, manganese ions, sodium ions, lead ions, zinc ions, fluoride ions, chloride ions, bromide ions, iodide ions, nitrite ions, bicarbonate ions, carbonate ions, sulfite ions, sulfate ions, phosphate ions, hydrogen phosphate ions, and dihydrogen phosphate ions.

10. A material for detecting the concentration of tricresyl phosphate in water, characterized in that: The invention comprises a 9-(2,2-dicyanovinyl)julidine solution using methanol or ethanol as a solvent.

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