Method for detecting electron donating capability of sediment based on three-dimensional fluorescence spectrum
By using p-benzoquinone and hydroquinone as fluorescent probes, the accuracy and efficiency problems of detecting electron-donating capacity in sediments in existing technologies have been solved. This method enables rapid, simple, and accurate detection of electron-donating capacity, and is applicable to the detection of sediments with different textures.
Patent Information
- Application Number
- CN202510910750.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-02
- Publication Date
- 2025-11-11
AI Technical Summary
Existing chemical probe methods and electrochemical methods suffer from low accuracy, high complexity, or limitations in sample size when detecting electron-donating capacity in groundwater sediments, making it difficult to achieve efficient and accurate detection.
Three-dimensional fluorescence spectroscopy was used, with p-benzoquinone and hydroquinone as fluorescent probes, to react with sediment samples under anaerobic conditions. The electron-donating capacity of the sediments was quantified by monitoring changes in fluorescence intensity, a concentration-fluorescence intensity standard curve was established, and the electron-donating capacity was calculated.
This invention provides a low-cost, simple, and efficient detection method that can quickly and accurately determine the electron-donating capacity of sediments. It is applicable to sediments of different textures, and the detection results are accurate and reproducible. It is suitable for the study of redox activity of riparian sediments.
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Figure CN120927630A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of chemical analysis and detection methods, and particularly relates to a method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy. Background Technology
[0002] The subsurface environment (soil, aquifers, etc.) is a crucial component of the Earth's critical zone, and its redox properties influence the biogeochemical cycles of elements and the migration, transformation, and remediation of pollutants. In-situ chemical / bioremediation and enhanced natural attenuation are common techniques for remediating contaminated subsurface environments. However, due to the chemical heterogeneity of aquifers, the dosage and remediation cycle of remediation agents are difficult to accurately assess. To effectively address these issues, accurate characterization of the redox heterogeneity of aquifers is necessary to precisely assess the dosage of remediation agents, thereby achieving green, economical, and efficient remediation of contaminated aquifers.
[0003] Electron donating capacity (EDC) of an aquifer refers to its potential ability to release electrons, which is related to the concentration of reduced reactive species within it. Studies have shown that sediments contribute more than 99% to the electron donating capacity of aquifers; therefore, understanding the electron donating capacity of aquifers hinges on sediments. Currently, there are many methods for detecting the electron donating capacity of sediments, which can be broadly categorized into chemical probe methods and electrochemical methods. However, these methods all have certain limitations. For example, chemical probe methods typically have low accuracy, long analysis cycles, and complex analytical processes; for instance, using potassium dichromate as an oxidant to test electron donating capacity requires a reaction at 150°C for 3 hours. Electrochemical methods offer high accuracy, but the testing is limited by the surface activity and volume of the working electrode, with the maximum sample dosage only a few milligrams, failing to represent the average properties of the aquifer medium. Furthermore, electrochemical testing requires a high level of specialized knowledge, hindering its widespread application in groundwater science. To address the numerous problems with existing technologies, there is an urgent need to develop a more efficient and effective method for detecting the electron donating capacity of sediments. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the background art above and to provide a method for detecting the electron-donating capacity (electron supply capacity) of sediments based on three-dimensional fluorescence spectroscopy.
[0005] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows: A method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy includes the following steps: (1) Under anaerobic conditions, p-benzoquinone and hydroquinone were dissolved in pH buffer solution to prepare solutions A and B respectively; (2) Under anaerobic conditions, the solutions A and B were diluted to different concentrations, and the fluorescence intensity at the excitation wavelength λex=290 nm and the emission wavelength λem=325 nm was read using a three-dimensional fluorescence spectrometer to establish the concentration-fluorescence intensity standard curves of p-benzoquinone and hydroquinone. (3) Mix the sediment sample to be tested with solution A, shake the mixture in the dark, filter it, and measure the fluorescence intensity of the filtrate; (4) The concentration change of p-benzoquinone in the filtrate was calculated based on the standard curve, and the electron-donating capacity of the sediment sample to be tested was calculated using the following formula: , E 样品 The electron-donating capacity of the sample to be tested is expressed in μmol e⁻ / g. C0 and C1 are the concentrations of p-benzoquinone before and after the reaction, respectively; n e- The number of electrons transferred by the fluorescent probe p-benzoquinone is n. e- It is 2; V The volume of the reaction system is expressed in liters (L). m 样品 The dry weight of the sediment sample is expressed in grams.
[0006] This invention uses p-benzoquinone (BQ) as an electron acceptor, which can accept electrons under anaerobic conditions and be reduced to hydroquinone (H2Q) by reducing components in the sediment. The reduction reaction is shown below: BQ + 2e - + 2H + → H2Q Since both BQ and H2Q are fluorescent active substances, and at specific excitation / emission wavelengths (λ... ex = 290 nm, λ em The fluorescence response varies at 325 nm. By monitoring the change in fluorescence intensity of BQ before and after the reaction, this invention can indirectly reflect the degree of reduction of BQ, thereby quantifying the electron-donating ability of the deposit.
[0007] In the above-mentioned method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy, preferably, the reaction time in step (3) is 20-30 minutes.
[0008] In the above-mentioned method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy, preferably, in step (3), the initial concentration of p-benzoquinone in solution A is 2-3 times higher than the electron-donating ability of the sediment sample to be tested.
[0009] In the above-mentioned method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy, preferably, in step (3), the amount of sediment sample to be tested added is 0.1-1 g, and the solid-liquid ratio in the mixed system is less than 10 g / L, so as to avoid the test error caused by the adsorption of the probe and the sample.
[0010] In the above-described method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy, preferably, in step (3), when the sediment sample to be tested is sandy sediment, the amount added is 0.2-1 g, and when the sediment sample to be tested is clayey sediment, the amount added is 0.1-1 g. If the sediment sample is viscous, it can be pre-dispersed evenly with an appropriate amount of anoxic water to avoid the sample not being able to fully contact the probe during the reaction process.
[0011] In the above-described method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy, preferably, in step (2), the linear relationship of the concentration-fluorescence intensity standard curve of p-benzoquinone is as follows: ,in, The unit is μM. Indicates the concentration of p-benzoquinone. F BQ Indicates the fluorescence intensity of p-benzoquinone; The linear relationship of the hydroquinone concentration-fluorescence intensity standard curve is as follows: ,in, The unit is μM. This indicates the concentration of hydroquinone. F H2Q This indicates the fluorescence intensity of hydroquinone.
[0012] In the above-mentioned method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy, preferably, in step (1), the pH value of the pH buffer is 7.0, which is prepared by adjusting boric acid and NaOH.
[0013] In the above-mentioned method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy, preferably, the anaerobic conditions refer to a mixed atmosphere with a volume concentration of 96% N2 + 4% H2.
[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The method for detecting electron-donating capacity of sediments provided by the present invention has low instrument cost, simple operation of the test process, few reagents required, short test cycle and high detection efficiency; and the method has good linearity, good experimental repeatability, and high accuracy and precision of the test results.
[0015] (2) The method for detecting electron-donating capacity of sediments provided by the present invention has a short analysis time, good repeatability and convenience, and low cost. It has good application prospects in characterizing the evolution law and mechanism of redox activity of riverine sediments and makes up for the weaknesses of existing technical means. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is the standard curve of p-benzoquinone and hydroquinone under fluorescence colorimetric method in the embodiments of the present invention; Figure 2 In this embodiment of the invention, three-dimensional fluorescence method was used to determine the EDC of 1 mM dissolved Fe(II) under different pH conditions; Figure 3 In this embodiment of the invention, the EDC of dissolved Fe(II) was determined by adding fluorescent probes at different concentration ratios in a three-dimensional fluorescence method in a pH=7 system. Figure 4 The kinetic curve of EDC of dissolved Fe(II) determined by three-dimensional fluorescence method at pH = 7 in an embodiment of the present invention is shown. Figure 5 Correlation analysis of electron supply capacity determination of sediment samples using two test systems in this embodiment of the invention; Figure 6 In this embodiment of the invention, three-dimensional fluorescence method is used to determine the EDC of sediment samples; Figure 7 In this embodiment of the invention, the spiked recovery rate of EDC in sediment samples was determined using a three-dimensional fluorescence method. Detailed Implementation
[0018] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.
[0019] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.
[0020] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.
[0021] This invention provides a method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy, comprising the following steps: (1) Under anaerobic conditions (a mixed atmosphere of 96% N2 + 4% H2 by volume), p-benzoquinone and hydroquinone were dissolved in pH buffer (prepared by adjusting boric acid and NaOH) to prepare solutions A and B respectively; (2) Under anaerobic conditions, the solutions A and B were diluted to different concentrations, and the fluorescence intensity at the excitation wavelength λex=290 nm and the emission wavelength λem=325 nm was read using a three-dimensional fluorescence spectrometer to establish the concentration-fluorescence intensity standard curves of p-benzoquinone and hydroquinone. (3) Mix the sediment sample to be tested with solution A, shake the mixture in the dark, filter it, and measure the fluorescence intensity of the filtrate; (4) The concentration change of p-benzoquinone in the filtrate was calculated based on the standard curve, and the electron-donating capacity of the sediment sample to be tested was calculated using the following formula: , E 样品 The electron-donating capacity of the sample to be tested is expressed in μmol e⁻ / g. C0 and C1 are the concentrations of p-benzoquinone before and after the reaction, respectively; n e- The number of electrons transferred by the fluorescent probe p-benzoquinone is n. e- It is 2; V The volume of the reaction system is expressed in liters (L). m 样品 The dry weight of the sediment sample is expressed in grams.
[0022] Example 1: A method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy includes the following steps: 1. Establishment of the standard curve for p-benzoquinone Weigh 61.83 mg of boric acid (H3BO3), dissolve it in 200 mL of ultrapure water, adjust the pH to 7 with 1 M NaOH, then purge with nitrogen for 15 min to remove oxygen, and transfer to an anaerobic glove box (96% N2 + 4% H2) to stand in the dark. Add 21.62 mg of p-benzoquinone (BQ), and stir anaerobically at room temperature in the dark for 10 min until the solid is completely dissolved, preparing a 1 mM p-benzoquinone solution.
[0023] Take 0.8 mL, 1.6 mL, 2.4 mL, 3.2 mL and 4 mL of 1 mM p-benzoquinone solution into 5 mL centrifuge tubes, respectively, and make up to 4 mL with deionized water to obtain standard solutions with BQ concentrations of 200 μM, 400 μM, 600 μM, 800 μM and 1000 μM.
[0024] Using a three-dimensional fluorescence spectrometer at wavelength λ ex =290 nm and emission wavelength λ em The fluorescence intensity of solutions at various concentrations was measured at 325 nm to establish a linear relationship between fluorescence intensity and p-benzoquinone concentration, resulting in a linear standard curve. ,in, The unit is μM. Indicates the concentration of p-benzoquinone. F BQ This indicates the fluorescence intensity of p-benzoquinone.
[0025] 2. Establishment of the hydroquinone standard curve Weigh 61.83 mg of boric acid (H3BO3), dissolve it in 200 mL of ultrapure water, adjust the pH to 7 with 1 M NaOH, purge with nitrogen for 15 min to remove oxygen, and then transfer to an anaerobic glove box (96% N2 + 4% H2) to stand in the dark. Add 22.02 mg of hydroquinone (H2Q), and stir anaerobically at room temperature in the dark for 10 min until the solid is completely dissolved, thus preparing a 1 mM hydroquinone solution.
[0026] Take 0.8 mL, 1.6 mL, 2.4 mL, 3.2 mL and 4 mL of 1 mM hydroquinone solution into 5 mL centrifuge tubes, respectively, and make up to 4 mL with oxygen-free deionized water to obtain standard solutions with H2Q concentrations of 200 μM, 400 μM, 600 μM, 800 μM and 1000 μM.
[0027] Using a three-dimensional fluorescence spectrometer at wavelength λ ex =290 nm and emission wavelength λ em The fluorescence intensity of solutions at various concentrations was measured at 325 nm to establish a linear relationship between fluorescence intensity and hydroquinone concentration, resulting in a linear standard curve. , in, The unit is μM. This indicates the concentration of hydroquinone. F H2Q This indicates the fluorescence intensity of hydroquinone.
[0028] like Figure 1 The figure shows the standard curves of p-benzoquinone and hydroquinone under the fluorescence colorimetric method.
[0029] 3. Determination of electron-donating capacity of sediment samples (1) Prepare a 1 mM p-benzoquinone solution using the same method as described in the method for establishing the p-benzoquinone standard curve.
[0030] (2) Weigh 0.1-0.2 g of sediment sample (sandy sediment and clay loam sediment) in advance, add 1 ml of the prepared 1 mM p-benzoquinone fluorescent probe solution to the sediment sample, and dilute with ultrapure water to 5 ml. Shake the sample in the dark at room temperature (25℃) for 30 min to reach stability. After the reaction, filter the sample using a 0.22 μm organic filter. The filtrate is the sample solution to be tested. (3) The fluorescence intensity changes before and after the reaction of p-benzoquinone solution with the sample were tested using the fluorescence detection method, and the specific results were recorded; (4) The concentration change of p-benzoquinone in the filtrate was calculated based on the standard curve, and the electron-donating capacity of the sediment sample to be tested was calculated using the following formula: The experimental records are shown in Table 1.
[0031] Table 1. Experimental record of electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy in Example 1.
[0032] The experimental data in Table 1 fully demonstrate the multiple advantages of the proposed three-dimensional fluorescence spectroscopy-based method for detecting electron-donating capacity in sediments. Firstly, the detection results in Table 1 show that this method can cover an extremely wide range of electron-donating capacities (EDCs), with a minimum detectable value as low as 0.02 μmole. - / g, up to 8.63 μmole - The method achieves a high EDC (electrode concentration) of [value missing] g, and even with adjustments to the dilution factor, accurate determination can still be achieved for high EDC samples, demonstrating excellent linear response. Secondly, the method exhibits excellent repeatability and stability; for example, the standard deviation of samples 2 and 3 at low EDC levels is close to 0, reflecting the ability to provide reliable data even in weak signal environments, indicating extremely high method sensitivity. Furthermore, the method is simple to operate and consumes few reagents. It only requires 20–30 minutes of anaerobic reaction at room temperature and detection via fluorescence reading, significantly superior to the high temperature, long reaction time, and specialized instrument operation requirements of traditional chemical probe methods or electrochemical methods. It is worth emphasizing that the method of this invention is applicable to sediment samples of different textures, and experimental verification has shown a high degree of consistency with the test results of dielectric electrochemical methods, combining accuracy and versatility.
[0033] Therefore, the data results in Table 1 demonstrate the comprehensive advantages of the method of detecting electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy in terms of sensitivity, stability, efficiency and adaptability, and further prove its application potential in rapid characterization of redox properties of sediments and assessment of contaminated site remediation.
[0034] Example 2: Condition Optimization Verification To screen and optimize the pH of the buffer solution, the required concentration of the fluorescent probe (solution A containing p-benzoquinone), and the mixing reaction time.
[0035] (1) The stabilization time of the fluorescent probe was investigated using kinetic experiments: The experiment was conducted at pH 7, with the fluorescent probe (p-benzoquinone) and dissolved FeSO4 mixed at a 1:1 ratio. The results are as follows: Figure 4 As shown, from Figure 4 As can be seen, the fluorescent probe reacts rapidly in the first 10 minutes, gradually stabilizes in 10-15 minutes, and shows significant stability after 20 minutes. Therefore, this invention selects 20-30 minutes as the optimal reaction time.
[0036] (2) The reaction between the fluorescent probe and dissolved FeSO4 was studied in the pH range of 5-9, and the results are as follows: Figure 2 As shown, the reaction produces less hydroquinone at pH 5. At pH 9, although a large amount of hydroquinone is produced, it leads to instability of the fluorescent probe, causing it to deteriorate rapidly. At pH 7, a large amount of hydroquinone is produced, and the yield is very close to the theoretical yield. Therefore, this invention selects pH = 7 as the optimal pH value. (3) Studies were conducted using fluorescent probe solutions of different concentrations (multiples of the corresponding dissolved Fe(II) concentration) at the optimal pH of 7. Figure 3 As shown, at pH = 7 and a dissolved Fe(II) concentration of 0.4 mM, the actual and theoretical yields of hydroquinone reach their maximum values when the ratio of fluorescent probe concentration to dissolved Fe(II) concentration is between 2 and 3. Therefore, this invention provides a method where a fluorescent probe concentration of 2-3 times the excess can be used for complete testing.
[0037] (4) Selection of reaction time: By analyzing the results of different reaction times, such as... Figure 4 As shown, a reaction time of 20-30 minutes allows for a complete reaction and yields a stable hydroquinone product. Excessive reaction time may lead to degradation of the fluorescent probe or the formation of byproducts, while insufficient reaction time may result in incomplete reaction. Therefore, this invention selects a reaction time of 20-30 minutes as the optimal condition to ensure complete reaction and prevent unnecessary side reactions.
[0038] In summary, the test conditions provided by this invention are as follows: the test environment is pH=7, the fluorescent probe solution is in excess by 2-3 times, and the mixing reaction time is 20-30 minutes.
[0039] Example 2: Method Validation (1) Comparison of the dielectric electrochemical method with the method of the present invention based on three-dimensional fluorescence spectroscopy for detecting the electron-donating ability of deposits.
[0040] First, the reduction capacity of 14 representative deposits was tested using a glassy carbon electrode. In the experiment, 40 mL of a 0.1 M KCl solution (containing 0.01 M MOPS, pH = 7.0) to remove dissolved oxygen was added to the reactor as a background electrolyte solution. Approximately 2 mL of the same background electrolyte solution was added to the counter electrode glass tube, ensuring the liquid level in the counter electrode glass tube was level with the liquid level in the working electrode reactor. The reactor was connected to an electrochemical workstation, and a constant voltage of +0.5 V (vs. Ag / AgCl) was set. Current-time curve testing was performed under the given potential conditions of the workstation, with stirring in the dark during the test. The electrochemical test program was started, and the oxidation current was continuously measured every 5 seconds to obtain the current-time curve. After the current stabilized, 1 mL of 10 mM 2,2'-adiazonium-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) (concentration 10 mM) was injected into the reactor, at which point an oxidation current response curve was generated. As time progresses, the current gradually decreases. When the reaction current returns to the baseline and stabilizes, it indicates that the oxidation of ABTS in the system has reached equilibrium. At this point, the sample of the deposit to be tested is added. Because the mediating substance facilitates the loss of electrons from the sample, an oxidation current continues to be generated. The time-current curve of the sample losing electrons is obtained using an electrochemical workstation. The electron supply capacity (EDC) is calculated by determining the peak area of the current response. The specific calculation formula is as follows:
[0041] Where EDC is the measured electron supply capacity of the sample, in moles of electrons. - / g; F is the Faraday constant, representing the charge carried by each mole of electrons, and its value is generally considered to be 96485 C / mol; t1 is the starting point of the current peak, in seconds; t2 is the end point of the current peak, in seconds; I(t) is a function of current changing with time, and the unit of current I is A; m represents the dry weight of the sample added, in grams.
[0042] Furthermore, the method of detecting the electron-donating ability of deposits based on three-dimensional fluorescence spectroscopy of the present invention was used for testing. The testing steps are the same as in Example 1.
[0043] like Figure 5 The diagram illustrates the correlation analysis of electron-donating capacity determination of sediment samples using two testing systems according to this embodiment. The results show that the method for detecting electron-donating capacity of sediments based on three-dimensional fluorescence spectroscopy provided by this invention is linearly correlated with the EDC test results of sediment samples of different textures determined by existing dielectric electrochemical methods, and the slope is close to 1. This indicates that the detection method provided by this invention has high accuracy.
[0044] (2) The accuracy and stability of the test method are evaluated by spiked recovery rate of the electron supply capacity of the sediment based on the added standard material.
[0045] Eight sediments of different textures were selected to test their electron supply capacity (EDC). The dosage for each sediment sample was 1 gram. Reduced chlorite was used for calibration. Based on the test results for each sediment, the molar electron ratio of the sample to the standard was calculated, and the dosage of the standard was adjusted by 0.5–1.5 times. In sediment samples with low EDC values (EAC / EDC < 0.5 μmol e⁻ / g), the dosage of the standard remained consistent with that used in individual standard tests. Three-dimensional fluorescence spectrometry (3D fluorescence) was used to test the EDC of the sediment samples for the first time. Then, the standard was added, and 3D fluorescence was used again to determine the reduction capacity of the mixture of sediment and standard. The EDC of the standard was calculated by the difference between the two test results and compared with the given electron capacity of the standard tested individually to further calculate the spiked recovery. The spiked recovery of each sample was analyzed at least three times to ensure the accuracy and repeatability of the experiment.
[0046] like Figure 6 The image shows the results of EDC determination of sediment samples using three-dimensional fluorescence method according to this embodiment. Figure 7 The figure shows the spiked recovery rate of EDC in sediment samples determined using three-dimensional fluorescence spectroscopy according to this embodiment. The results show that the spiked recovery rate is 102.4 ± 8.1%. This result indicates that the method for detecting electron-donating capacity of sediments based on three-dimensional fluorescence spectroscopy provided by this invention has high accuracy and stability, and is suitable for electron supply capacity analysis of sediments with different textures.
[0047] The test results of this embodiment show that the test results have good stability and are applicable and accurate for practical use.
Claims
1. A method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy, characterized in that, Includes the following steps: (1) Under anaerobic conditions, p-benzoquinone and hydroquinone were dissolved in pH buffer solution to prepare solutions A and B respectively; (2) Under anaerobic conditions, the solutions A and B were diluted to different concentrations, and the fluorescence intensity at the excitation wavelength λex=290 nm and the emission wavelength λem=325 nm was read using a three-dimensional fluorescence spectrometer to establish the concentration-fluorescence intensity standard curves of p-benzoquinone and hydroquinone. (3) Mix the sediment sample to be tested with solution A, shake the mixture in the dark, filter it, and measure the fluorescence intensity of the filtrate; (4) The concentration change of p-benzoquinone in the filtrate was calculated based on the standard curve, and the electron-donating capacity of the sediment sample to be tested was calculated using the following formula: , E 样品 The electron-donating capacity of the sample to be tested is expressed in μmol e⁻ / g. C0 and C1 are the concentrations of p-benzoquinone before and after the reaction, respectively; n e- The number of electrons transferred is the number of electrons in p-benzoquinone; V The volume of the reaction system is expressed in liters (L). m 样品 The dry weight of the sediment sample is expressed in grams.
2. The method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy as described in claim 1, characterized in that, In step (3), the reaction time is 20-30 minutes.
3. The method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy as described in claim 1, characterized in that, In step (3), the initial concentration of p-benzoquinone in solution A is 2-3 times higher than the electron-donating ability of the sediment sample to be tested.
4. The method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy as described in claim 1, characterized in that, In step (3), the amount of sediment sample to be tested added is 0.1-1 g, and the solid-liquid ratio in the mixed system is less than 10 g / L.
5. The method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy as described in claim 4, characterized in that, In step (3), when the sediment sample to be tested is sandy sediment, the amount added is 0.2-1 g, and when the sediment sample to be tested is clayey sediment, the amount added is 0.1-1 g.
6. The method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy as described in claim 1, characterized in that, In step (2), the linear relationship of the concentration-fluorescence intensity standard curve of p-benzoquinone is as follows: ,in, The unit is μM. Indicates the concentration of p-benzoquinone. F BQ Indicates the fluorescence intensity of p-benzoquinone; The linear relationship of the hydroquinone concentration-fluorescence intensity standard curve is as follows: ,in, The unit is μM. This indicates the concentration of hydroquinone. F H2Q This indicates the fluorescence intensity of hydroquinone.
7. The method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy as described in claim 1, characterized in that, In step (1), the pH value of the pH buffer solution is 7.0, which is prepared by adjusting boric acid and NaOH.
8. The method for detecting the electron-donating ability of sediments based on three-dimensional fluorescence spectroscopy as described in claim 1, characterized in that, The anaerobic conditions refer to a mixed atmosphere with a volume concentration of 96% N2 + 4% H2.