Method for detecting organic solvent in high-salinity wastewater
By combining ethyl acetate extraction and gas chromatography analysis, the problems of poor separation effect and high detection cost of organic solvent detection in high-salt wastewater were solved, and efficient, accurate and simple detection effects were achieved, which is suitable for high-salt wastewater with complex matrices.
Patent Information
- Application Number
- CN202510922280.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-04
- Publication Date
- 2025-09-16
AI Technical Summary
Existing technologies for detecting organic solvents in high-salt wastewater suffer from problems such as poor separation, expensive equipment, complex pretreatment, and limited selection of detection methods, making it difficult to achieve accurate and efficient detection.
The ethyl acetate extraction method is combined with gas chromatography analysis. Through the extraction, separation and quantification steps, a DB-WAX chromatographic column, nitrogen carrier gas and a specific column temperature program are used, combined with the internal standard method to calculate the organic matter content to ensure the accuracy and simplicity of detection.
It achieves efficient and accurate detection of organic solvents in high-salt wastewater, simplifies the operating process, reduces detection costs, is applicable to the detection of a variety of organic matter, and improves the reliability of detection results and economic benefits.
Smart Images
Figure CN120652000A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of high-salt wastewater detection in the field of environmental protection, and in particular to a method for detecting organic solvents in high-salt wastewater. Background Art
[0002] High-salinity wastewater is widely found in industries such as chemical, pharmaceutical, food processing, oil and gas, printing and dyeing, and metalworking. This wastewater typically contains large amounts of inorganic salts (such as NaCl, CaCl2, and Na2SO4), with conductivity often exceeding 10,000 μS / cm. Furthermore, the wastewater may also contain complex organic compounds such as phenols, esters, aldehydes, polycyclic aromatic hydrocarbons (PAHs), pesticide residues, and surfactants. Due to the complex matrix characteristics of high-salinity wastewater, traditional organic compound detection methods face numerous challenges in practical application.
[0003] Limitations of existing technologies Direct injection technology: Whole-column imaging capillary electrophoresis (CPI-CE): Although it can tolerate high salt environments, it is prone to poor separation effects when dealing with complex matrices.
[0004] High-resolution mass spectrometry (HRMS): such as time-of-flight mass spectrometry (TOF-MS), eliminates salt interference through accurate mass numbers and is suitable for the qualitative analysis of complex unknown organic compounds, but the equipment is expensive.
[0005] Conventional detection methods: Ultraviolet spectrophotometry: Due to the interference of salt absorption, the results may be biased, and it is difficult to accurately determine the organic matter content in high-salt wastewater.
[0006] Specific gravity method: Traditionally used to test the specific gravity of materials after distillation to determine whether the organic solvent meets the requirements. This method can only be accurate to about 0.1%, with a large error, cannot effectively guide production, and is likely to lead to serious losses.
[0007] Preprocessing is complex: High-salt wastewater needs to be removed or its salt concentration reduced to avoid damage to instruments (such as chromatographic columns and mass spectrometers), which increases the complexity and cost of pretreatment.
[0008] Limited choice of methods: There are many types of organic matter in high-salt wastewater, and the physical and chemical properties of different organic matter vary greatly, making it difficult for a single detection method to meet all needs. Summary of the Invention
[0009] (1) Technical problems solved In view of the deficiencies of the prior art, the present invention provides a method for detecting organic solvents in high-salt wastewater.
[0010] (2) Technical solution To achieve the above object, the present invention provides the following technical solution: A method for detecting organic solvents in high-salt wastewater of the present invention comprises the following steps: Extraction steps: Take a high-salt wastewater sample, add ethyl acetate extractant, shake and let it stand; Separation step: separate and collect the organic phase, release the waste water at the bottom, and collect the upper ethyl acetate extract; Repeat the extraction steps: add ethyl acetate again, repeat the shaking and letting it stand, collect the ethyl acetate extract and dilute to the volume in a volumetric flask; Detection steps: Use gas chromatography to analyze the organic solvent components in ethyl acetate; Quantitative steps: Prepare methanol-ethyl acetate standard samples and calculate the organic matter content by peak area ratio.
[0011] Preferably, in the extraction step, 50 mL of the high-salt wastewater sample is taken, 10 mL of ethyl acetate is used as the extractant, and the sample is allowed to stand for 30 minutes after shaking. In the repeated extraction step, 10 ml of ethyl acetate was added again, and the capacity of the volumetric flask was 25 ml. Further preferably, the purity of ethyl acetate in the extraction step is high purity, and the extraction temperature is 20-25°C.
[0012] Again preferably, the shaking condition is mechanical shaking at 200 rpm for 1 minute, and the separating funnel is tilted at 45° during standing and stratification.
[0013] Preferably, in the detection step, the gas chromatography analysis conditions are as follows: Chromatographic column: DB-WAX, length 30 m, inner diameter 0.32 mm, film thickness 0.5 μm Chromatographic carrier gas was nitrogen, with an average flow rate of 5 mL / min and a split ratio of 10:1. The column temperature was 50°C, maintained for 5 minutes, then increased at 30°C / min to 150°C and maintained for 3 minutes. Inlet temperature: 200°C; detector temperature: 300°C; headspace temperature: 80°C; Injection volume: 2 µL; Repeat the test 3 times and take the average value.
[0014] Further preferably, in the quantitative step, the standard sample is prepared by taking 1.00 ml of methanol and adding it to a 25 ml volumetric flask, making up the volume with ethyl acetate, and mixing well for testing.
[0015] Again preferably, in the quantitative step, the step of calculating the organic matter content by peak area ratio is as follows: taking 10 μL of the sample and the standard sample after extraction with ethyl acetate, respectively, detecting by gas chromatography, repeating 3 times, calculating the average peak area, and finally dividing the peak area of the standard sample by the peak area of the sample. The calculation formula is: organic matter content = × .
[0016] Preferably, the electrical conductivity of the high-salt wastewater is greater than 10,000 μS / cm, and the salt content is greater than or equal to 5% in terms of NaCl.
[0017] More preferably, the organic matter includes at least one of esters, ketones, aldehydes or aromatic compounds.
[0018] Again preferably, a pretreatment step is also included: the wastewater sample is filtered through a 0.45 μm filter membrane to remove suspended matter.
[0019] (3) Beneficial effects Compared with the prior art, the present invention provides a method for detecting organic solvents in high-salt wastewater, which has the following beneficial effects: Efficient extraction Ethyl acetate as an extractant: Ethyl acetate has good solubility and can effectively extract organic matter (such as esters, ketones, aldehydes, or aromatic compounds) from wastewater. Each extraction uses 10 ml of ethyl acetate. Mechanical agitation at 200 rpm for 1 minute and stratification at a 45° angle ensures extraction efficiency, reduces emulsification, and improves separation.
[0020] Multiple extractions: By extracting twice and combining the extracted samples to a 25 ml volumetric flask, the extraction rate of organic matter is further improved, ensuring the accuracy of the test results.
[0021] Accurate detection Optimization of gas chromatography analysis conditions: A DB-WAX column (30 m long, 0.32 mm inner diameter, 0.5 μm film thickness) was used, with nitrogen as the carrier gas, an average flow rate of 5 mL / min, and a split ratio of 10:1. Combined with a specific column temperature program (initial temperature of 50°C for 5 minutes, then heated to 150°C at 30°C / min and maintained at this temperature for 3 minutes), this ensured that organic compounds with different boiling points could be effectively separated and detected.
[0022] Repeat detection: The injection volume was 2 µL each time, and the detection was repeated 3 times to obtain the average value to ensure the reliability and reproducibility of the data.
[0023] Easy to operate Pretreatment step: The wastewater sample was filtered through a 0.45 μm filter membrane to remove suspended matter, which simplified the subsequent operation steps and avoided the interference of particulate matter on the test results.
[0024] Standardized process: The entire testing process is simple and clear, easy to operate, suitable for laboratory and industrial environments, and reduces the possibility of human error.
[0025] Wide applicability Applicable to a variety of organic matter: This method is not only suitable for the detection of organic matter such as esters, ketones, aldehydes or aromatic compounds, but can also treat high-salt wastewater with a salt content ≥5% (calculated as NaCl) and a conductivity >10000μS / cm, and has wide applicability.
[0026] Economical and efficient: Compared with existing technologies, this technical solution reduces detection costs and shortens detection time while ensuring detection accuracy, thus significantly improving economic benefits.
[0027] Quantitative accuracy Standard sample preparation and peak area ratio calculation: By preparing a methanol-ethyl acetate standard and calculating the organic content using the peak area ratio, the accuracy of the quantitative results is ensured. The calculation formula is: Organic content = (sample peak area / standard peak area) * 1000 / 50, making the test results more accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 Schematic diagram of the pretreatment steps of the present invention; Figure 2 Schematic diagram of the extraction steps of the present invention; Figure 3 Schematic diagram of the detection and quantification steps of the present invention; DETAILED DESCRIPTION The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0029] See also Figure 1-3 The present invention provides a method for detecting organic solvents in high-salt wastewater, comprising the following steps: Extraction steps: Take a high-salt wastewater sample, add ethyl acetate extractant, shake and let it stand; Separation step: separate and collect the organic phase, release the waste water at the bottom, and collect the upper ethyl acetate extract; Repeat the extraction steps: add ethyl acetate again, repeat the shaking and letting it stand, collect the ethyl acetate extract and dilute to the volume in a volumetric flask; Detection steps: Use gas chromatography to analyze the organic solvent components in ethyl acetate; Quantitative steps: Prepare methanol-ethyl acetate standard samples and calculate the organic matter content by peak area ratio.
[0030] This technical solution combines solvent extraction with gas chromatography analysis to achieve efficient and accurate detection of organic matter in complex matrices. This method is particularly suitable for wastewater containing high concentrations of inorganic salts and complex organic matter, resolving the issues of high interference and high error associated with traditional detection methods.
[0031] Solvent extraction step Ethyl acetate as an extractant: Ethyl acetate is a weakly polar organic solvent with good solubility for esters, ketones, aldehydes, aromatic compounds, etc. It is suitable for extracting target compounds from aqueous phases or polar solvents.
[0032] Purity requirement: The purity of ethyl acetate should be high purity to ensure that no impurities are introduced during the extraction process and affect the test results.
[0033] Temperature control: The extraction temperature should be kept at 20-25°C to avoid volatilization loss caused by too high temperature or dissolution effect affected by too low temperature.
[0034] By utilizing the high solubility of ethyl acetate (dielectric constant 6.0) for medium polar organic matter, organic solvents in wastewater are separated by liquid-liquid extraction. The principle is as follows: Like dissolves like mechanism: The solubility of organic compounds such as esters and ketones in ethyl acetate is 10-20 times higher than that in aqueous phase. For example, the partition coefficient of ethyl acetate to benzaldehyde is K=15.7. Two-phase separation characteristics: The density difference between ethyl acetate and water (0.902g / cm³ vs 1.0g / cm³) makes the separation speed three times faster than that of ether, and a clear interface can be formed after standing for 30 minutes; Anti-salt interference design: Although the ionic strength in high-salt wastewater changes the activity coefficient of organic matter, the hydrophobicity of ethyl acetate (logP=0.73) enables it to still be effectively extracted.
[0035] Separation steps Mechanical shaking: Use mechanical shaking at 200 rpm for 1 minute to ensure full contact between ethyl acetate and wastewater and improve extraction efficiency.
[0036] Standing stratification: The separating funnel is tilted at 45° to facilitate rapid stratification, reduce emulsification, and ensure separation effect.
[0037] Repeat the extraction steps Multiple extractions: To ensure complete extraction, add 10 ml of ethyl acetate for a second extraction, and combine the two extracts to a 25 ml volumetric flask to improve detection sensitivity.
[0038] Gas chromatography detection steps The DB-WAX polar column (polyethylene glycol stationary phase) is used to separate organic compounds based on the following mechanism: Polarity matching separation: The stationary phase forms hydrogen bonds with esters, aldehydes, etc., and organic compounds with low boiling points elute first. For example, methanol (boiling point 64.7°C) has a retention time of 2.1 minutes, and ethyl acetate (boiling point 77.1°C) has a retention time of 3.5 minutes. Temperature program optimization: maintain at 50°C for 5 minutes to separate low-boiling-point components, and increase the temperature to 150°C at 30°C / min to elute high-boiling-point substances, with a peak resolution R ≥ 1.5; FID detection mechanism: Organic matter is ionized in a hydrogen flame to produce an ion flow. The signal intensity is proportional to the mass of the organic matter, and the detection limit is 0.1 mg / L.
[0039] Quantitative calculation steps The linear relationship between peak area ratio and concentration was established based on the internal standard method: Standard calibration: Take 1.00 ml of methanol and add it to a 25 ml volumetric flask, make up to volume with ethyl acetate, mix well and test to ensure the accuracy and stability of the standard; Sample calculation: Take 10µL of the sample and standard sample extracted with ethyl acetate and tested by gas chromatography, repeat 3 times, calculate the average peak area, and finally divide the peak area of the standard sample by the peak area of the sample. The formula is as follows: Organic matter content = × ; Where 1000 is the standard sample concentration conversion factor, and 50 is the wastewater sampling volume (mL); Example calculation: If the sample peak area = 8500, the standard peak area = 12000, then: Content = × =14.17 mg / L; Error calibration: If the detected temperature deviates from 20-25°C, a correction of 0.3% is made for each °C. For example, at 28°C, the measured value is multiplied by 0.988 (i.e., 1-3×0.004). When the wastewater conductivity is greater than 20,000 μS / cm, multiply it by a matrix correction factor of 1.05 (experimental verification shows that the recovery rate decreases by an average of 5% in high-salt matrices).
[0040] Working principle of the optimal technical solution Optimization of extraction conditions Premium pure ethyl acetate: purity ≥99.8%, impurity peak ≤0.1%, to avoid interference with sample detection (e.g., methanol impurity peak overlaps with the target compound); 20-25℃ extraction temperature: In this range, the ethyl acetate viscosity (0.42-0.45mPa・s) and the partition coefficient K fluctuate by ≤3%. For every 10℃ increase in temperature, the K value decreases by approximately 5%. 200rpm mechanical oscillation: The turbulent effect increases the contact area between the two phases to three times that of static extraction, improving extraction efficiency by 27%. The risk of emulsification increases when the oscillation intensity exceeds 300rpm.
[0041] Chromatographic parameter optimization DB-WAX column: 30m long column provides 1.2×10 4 Theoretical plate number, 0.5μm film thickness reduces tailing of high boiling point substances (tailing factor ≤ 1.1); Nitrogen carrier gas (5 mL / min): linear velocity of 15 cm / s close to the optimal separation speed, split ratio of 10:1 to reduce matrix effects and avoid column overloading; Headspace 80℃: makes ethyl acetate vaporization efficiency reach 95%, while preventing condensation of high boiling point organic matter, and the vaporization chamber temperature of 200℃ ensures instant vaporization.
[0042] Preprocessing and quantitative improvement 0.45μm membrane filtration: removes suspended solids ≥0.45μm (such as calcium carbonate particles) in wastewater to prevent clogging of the chromatographic column. The column efficiency drop rate is measured to be reduced by 80% after filtration. Three repeated tests: random errors were reduced by statistical methods, with the measured RSD ≤ 0.8%, which is 62% lower than the error of a single test; High-salt matrix adaptation: When the conductivity is greater than 10,000 μS / cm, the organic matter recovery rate can reach 98.3% by using two extractions (10 mL × 2), which is 12% higher than that of a single extraction.
[0043] Detailed workflow summary Step S1: Preprocessing Membrane filtration: Take 50 ml of high-salt wastewater sample and filter it through a 0.45 μm filter membrane to remove suspended matter and ensure the purity of the sample.
[0044] Step S2: Extraction Add extractant: Add 10 ml of ethyl acetate extractant to the filtered wastewater sample.
[0045] Oscillation: Use a mechanical oscillator at 200 rpm for 1 minute to ensure that ethyl acetate is fully in contact with the wastewater.
[0046] Standing and separating: Tilt the separatory funnel at 45° and let it stand for 30 minutes to allow the organic phase and aqueous phase to separate naturally.
[0047] Step S3: Separation Separate and collect the organic phase: discharge the waste water at the bottom and collect the upper ethyl acetate extract.
[0048] Step S4: Repeat extraction Re-extraction: Add another 10 ml of ethyl acetate and repeat the shaking and standing steps to ensure complete extraction.
[0049] Make up the volume: Combine the two extracts and make up the volume to 25 ml volumetric flask for the next step of testing.
[0050] Step S5: Detection Gas chromatography analysis: Use a gas chromatograph to analyze the organic solvent components in ethyl acetate according to the set conditions (chromatographic column, carrier gas, column temperature program, injection port temperature, detector temperature, etc.).
[0051] Injection volume: 2 µL per injection, repeat the test 3 times and take the average value to ensure data accuracy.
[0052] Step S6: Quantification Standard sample preparation: Take 1.00 ml of methanol and put it into a 25 ml volumetric flask, make up to volume with ethyl acetate, mix well and prepare for testing.
[0053] Calculation of peak area ratio: Take 10µL of the sample and standard sample (divided into volumes after extraction with ethyl acetate) respectively, and detect by gas chromatography. Repeat three times, calculate the average peak area, and finally divide the peak area of the standard sample by the peak area of the sample. The calculation formula is: Organic matter content = (sample peak area / standard peak area) * 1000 / 50.
[0054] Comparative experiment By adding a known amount of methanol to the extract and detecting the change in peak area, the linear response capability, recovery accuracy and anti-matrix interference ability of the detection method are verified. The core logic is: if the method is reliable, the amount of added methanol and the detected peak area should be in a strictly linear relationship, and the ratio of the newly added peak area to the standard sample peak area should be consistent with theoretical expectations.
[0055] Comparison 1: 1mL methanol addition experiment Procedure: After extraction, add 1 mL of methanol (concentration 40 mg / L) to make up to 25 mL and measure the peak area; effect: Linear starting point verification: Verify the response accuracy of the method when adding low concentrations. If the ratio of the peak area increase to the standard sample peak area is 1:1 (i.e., the added peak area ≈ the standard sample peak area × 1mL / 25mL), it proves that the method has good linearity in the low concentration range; Matrix effect test: After adding methanol to the high-salt wastewater matrix, if the peak area is not attenuated due to salt interference, it means that the extraction step has effectively removed the matrix interference.
[0056] Comparison 2: 2mL methanol addition experiment Procedure: Add 2 mL of methanol (concentration 80 mg / L), adjust to volume, and then test; effect: Linear range expansion: Verify the linear response of the method in the medium concentration range. If the peak area increase is twice that of comparison 1, it proves that the linear range covers at least 40-80 mg / L. Repeatability verification: The repeatability of the instrument was tested by doubling the addition amount. If RSD ≤ 0.1%, it was proved that the method stability met the standard.
[0057] Comparison 3: 3mL methanol addition experiment Procedure: Add 3 mL of methanol (concentration 120 mg / L), adjust to volume, and then test; effect: Linear upper limit test: Verify the applicability of the method in the high concentration range. If the peak area is still linear with the added amount, it proves that the method can cover a wide concentration range; Recovery rate verification: Theoretically, the peak area corresponding to 3 mL of methanol should be 3 times the peak area of the standard sample. If the deviation between the measured value and the theoretical value is ≤0.1%, it proves that the recovery rate is above 99.9%.
[0058] Proof of linear relationship: If the ratios of the newly added peak area to the amount of added methanol in comparisons 1-3 are 1:1, 2:1, and 3:1, respectively, and are consistent with the ratios of the standard peak areas, then it is proven that the method satisfies the linear relationship y=kx (k is the response factor) and the quantitative model is reliable.
[0059] Anti-interference capability verification: The salt in high-salt wastewater (such as NaCl) may inhibit the ionization of organic matter, but the peak area in the comparative experiment still increases strictly linearly, indicating that: Ethyl acetate extraction has effectively separated organic matter and salts, with matrix interference ≤0.1%; The GC conditions (eg, split ratio 10:1) eliminated the effects of residual salts on the detector.
[0060] Advantages of internal standard method: In the comparative experiment, methanol was used as the internal standard, and its peak area was not affected by the sample matrix, proving that the internal standard method can correct the following errors: injection volume fluctuation (peak area ratio remains unchanged at ±0.5 μL); Detector sensitivity drift (stable response when temperature fluctuates ±1°C).
[0061] Accuracy data: The deviation between the measured peak area and the theoretical value in the comparative experiment is ≤0.1%. For example, when 2 mL of methanol is added, the measured peak area should be twice that of the standard. If the error is ≤0.1%, the method is considered to meet the standard. Repeatability data: RSD (relative standard deviation) of three comparative experiments is ≤0.8%, meeting industrial testing requirements (GB / T27417-2017 stipulates RSD ≤ 1%); Recovery data: The recovery rate of methanol addition reached 99.7%-100.3%, proving that the method has no systematic error and can be used for precise quantification.
[0062] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.
Claims
1. A method for detecting organic solvents in high-salt wastewater, characterized in that: The following steps are involved: Extraction steps: Take a high-salt wastewater sample, add ethyl acetate extractant, shake and let it stand; Separation step: separate and collect the organic phase, release the waste water at the bottom, and collect the upper ethyl acetate extract; Repeat the extraction steps: add ethyl acetate again, repeat the shaking and letting it stand, collect the ethyl acetate extract and dilute to the volume in a volumetric flask; Detection steps: Use gas chromatography to analyze the organic solvent components in ethyl acetate; Quantitative steps: Prepare methanol-ethyl acetate standard samples and calculate the organic matter content by peak area ratio.
2. The method for detecting organic solvents in high-salt wastewater according to claim 1, wherein: In the extraction step, 50 mL of high-salt wastewater sample was taken, 10 mL of ethyl acetate was used as the extractant, and the sample was allowed to stand for 30 minutes after shaking. In the repeated extraction step, 10 ml of ethyl acetate was added again, and the capacity of the volumetric flask was 25 ml.
3. The method for detecting organic solvents in high-salt wastewater according to claim 1, wherein: The purity of ethyl acetate in the extraction step is high-grade purity, and the extraction temperature is 20-25°C.
4. The method for detecting organic solvents in high-salt wastewater according to claim 1, wherein: The shaking conditions are mechanical shaking at 200 rpm for 1 minute, and the separating funnel is tilted at 45° when the mixture is allowed to stand and separate into layers.
5. The method for detecting organic solvents in high-salt wastewater according to claim 1, wherein: In the detection step, the gas chromatography analysis conditions are as follows: Chromatographic column: DB-WAX, length 30 m, inner diameter 0.32 mm, film thickness 0.5 μm Chromatographic carrier gas was nitrogen, with an average flow rate of 5 mL / min and a split ratio of 10:
1. The column temperature was 50°C, maintained for 5 minutes, then increased at 30°C / min to 150°C and maintained for 3 minutes. Inlet temperature: 200°C; detector temperature: 300°C; headspace temperature: 80°C; Injection volume: 2 µL; Repeat the test 3 times and take the average value.
6. The method for detecting organic solvents in high-salt wastewater according to claim 1, wherein: In the quantitative step, the standard sample is prepared by taking 1.00 ml of methanol and adding it to a 25 ml volumetric flask, making up the volume with ethyl acetate, and mixing it until it is tested.
7. The method for detecting organic solvents in high-salt wastewater according to claim 1, wherein: In the quantitative step, the step of calculating the organic matter content by peak area ratio is as follows: 10 μL of the sample and the standard sample, which were extracted with ethyl acetate and fixed to a certain volume, were respectively taken, and detected by gas chromatography, repeated 3 times, and the average peak area was calculated. Finally, the peak area of the standard sample was divided by the peak area of the sample. The calculation formula is: Organic matter content = × .
8. The method for detecting organic solvents in high-salt wastewater according to claim 1, wherein: The electrical conductivity of the high-salt wastewater is greater than 10,000 μS / cm, and the salt content is greater than or equal to 5% in terms of NaCl.
9. The method for detecting organic solvents in high-salt wastewater according to claim 1, wherein: The organic matter includes at least one of esters, ketones, aldehydes or aromatic compounds.
10. The method for detecting organic solvents in high-salt wastewater according to claim 1, characterized in that: A pretreatment step is also included: the wastewater sample is filtered through a 0.45 μm filter membrane to remove suspended matter.