A rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzene[a]pyrene in soil
Patent Information
- Application Number
- CN202611367832.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-04
- Publication Date
- 2026-10-23
AI Technical Summary
[0006]本发明的目的是为了解决现有常规气相色谱-质谱联用、高效液相色谱等土壤多环芳烃检测技术过度依赖大型仪器、前处理操作繁琐且检测周期长，难以满足场地污染筛查与快速定量需求的问题，而提供一种土壤中多环芳烃菲和苯并[a]芘的快速检测方法
[0017]1.本发明简化了土壤样品前处理流程，无需固相萃取、氮吹浓缩等复杂操作，结合纳米金增强基底的表面增强拉曼效应，可实现土壤中菲和苯并[a]芘的快速定性识别与定量检测，操作简便、检测周期短，适用于场地土壤污染的快速筛查。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of environmental pollutant detection technology, specifically to a rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil. Background Technology
[0002] Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants containing two or more fused benzene rings. They are commonly found in the soil of chemical legacy sites and have carcinogenic, teratogenic, and mutagenic effects. They can migrate into the food chain through soil-groundwater exchange, posing a serious threat to the ecological environment and human health. Among them, phenanthrene and benzo[a]pyrene are typical PAH pollutants in soil and are key monitoring indicators in site soil pollution investigations.
[0003] Currently, the conventional methods for detecting polycyclic aromatic hydrocarbons (PAHs) in soil are mainly gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). These methods have high accuracy, but they have drawbacks such as complex pretreatment processes, long detection cycles, reliance on large instruments, and inability to achieve rapid on-site detection. They are difficult to meet the needs of large-scale screening and rapid assessment of chemical legacy sites.
[0004] Surface-enhanced Raman spectroscopy (SERS) technology is characterized by strong fingerprint recognition, high sensitivity, and fast detection speed. Combined with a portable Raman spectrometer, it can achieve on-site detection. Existing Raman spectroscopy-based methods for detecting polycyclic aromatic hydrocarbons (PAHs) in soil often require multiple pretreatment steps, such as solid-phase extraction purification, nitrogen drying, and solvent reconstitution. These procedures are cumbersome, consume a large amount of reagents, and there is still room for improvement in detection efficiency.
[0005] Therefore, developing a method that is simple to pretreatment, quick to operate, and can rapidly and quantitatively detect phenanthrene and benzo[a]pyrene in soil is of great application value for rapid screening of site pollution. Summary of the Invention
[0006] The purpose of this invention is to address the problems of existing conventional gas chromatography-mass spectrometry and high-performance liquid chromatography (HPLC) techniques for detecting polycyclic aromatic hydrocarbons (PAHs) in soil, which rely excessively on large instruments, have cumbersome pretreatment procedures, and have long detection cycles, making it difficult to meet the needs of site pollution screening and rapid quantification. Therefore, this invention provides a rapid detection method for PAHs phenanthrene and benzo[a]pyrene in soil.
[0007] A rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil, comprising the following steps:
[0008] Step S1: Sample extraction;
[0009] Soil samples containing phenanthrene and benzo[a]pyrene were ground, sieved, added to a non-polar organic solvent, and extracted by ultrasonication to obtain an extract.
[0010] Step S2: Sample purification;
[0011] Centrifuge the extract obtained in step S1, take the supernatant, filter it through an organic filter membrane to obtain the test solution;
[0012] Step S3: Sample purification;
[0013] After the test solution obtained in step S1 is mixed evenly with the gold nanoparticle sol, it is placed in a Raman spectrometer to collect the surface-enhanced Raman spectrum.
[0014] Step S4: Quantitative analysis;
[0015] Characteristic Raman peaks of phenanthrene and benzo[a]pyrene were selected respectively, and the measured peak intensities were substituted into the pre-established standard curve to calculate the contents of phenanthrene and benzo[a]pyrene in the soil sample.
[0016] The beneficial effects of this invention are:
[0017] 1. This invention simplifies the soil sample pretreatment process, eliminating the need for complex operations such as solid-phase extraction and nitrogen blowing concentration. Combined with the surface-enhanced Raman effect of the nano-gold reinforced substrate, it enables rapid qualitative identification and quantitative detection of phenanthrene and benzo[a]pyrene in soil. The operation is simple and the detection cycle is short, making it suitable for rapid screening of site soil pollution.
[0018] 2. The pretreatment process is simple, requiring only two steps: ultrasonic extraction with organic solvent and centrifugal filtration to obtain the test solution. This eliminates the cumbersome operations such as solid-phase extraction purification, nitrogen drying, and solvent reconstitution, significantly shortening the sample pretreatment time. A single sample can be processed and the test results obtained within 30 minutes, making it suitable for rapid quantification.
[0019] 3. The nano-gold sol prepared by sodium citrate reduction method is used as the SERS enhancement substrate. The preparation method is simple and has good stability. It can achieve good Raman enhancement without the need for additional salt flocculants. The detection system is simple to operate and requires less reagent.
[0020] 4. The method has good sensitivity, with detection limits of up to 10 for phenanthrene and benzo[a]pyrene. -7 With a concentration of mol / L and good linearity, it can meet the quantitative detection requirements of trace polycyclic aromatic hydrocarbons in soil. At the same time, it can achieve qualitative identification of two pollutants through characteristic Raman peaks, thus possessing both qualitative and quantitative detection capabilities.
[0021] 5. The detection uses a quartz capillary tube for sample introduction, resulting in low sample consumption. It is compatible with portable Raman spectrometers and can support rapid on-site detection and batch screening of polycyclic aromatic hydrocarbon pollution in soil at chemical waste sites.
[0022] This invention provides a rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil. Attached Figure Description
[0023] Figure 1 The surface-enhanced Raman spectra of different concentrations of phenanthrene in Example 1 are shown.
[0024] Figure 2 The surface-enhanced Raman spectra of benzo[a]pyrene at different concentrations in Example 1 are shown.
[0025] Figure 3 This is a standard curve showing the intensity of the characteristic Raman peak of phenanthrene versus its concentration in Example 1.
[0026] Figure 4 This is a standard curve showing the characteristic Raman peak intensity of benzo[a]pyrene versus concentration in Example 1;
[0027] Figure 5 This shows the surface-enhanced Raman spectrum of an actual soil sample collected from a chemical waste site in Example 1. Detailed Implementation
[0028] Specific Implementation Method 1: This implementation method provides a rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil, which is carried out according to the following steps:
[0029] Step S1: Sample extraction;
[0030] Soil samples containing phenanthrene and benzo[a]pyrene were ground, sieved, added to a non-polar organic solvent, and extracted by ultrasonication to obtain an extract.
[0031] Step S2: Sample purification;
[0032] Centrifuge the extract obtained in step S1, take the supernatant, filter it through an organic filter membrane to obtain the test solution;
[0033] Step S3: Sample purification;
[0034] After the test solution obtained in step S1 is mixed evenly with the gold nanoparticle sol, it is placed in a Raman spectrometer to collect the surface-enhanced Raman spectrum.
[0035] After mixing, no static reaction is required; spectral data can be collected directly.
[0036] Step S4: Quantitative analysis;
[0037] The characteristic Raman peaks of phenanthrene and benzo[a]pyrene were selected respectively, and the measured peak intensities were substituted into the pre-established standard curve to calculate the contents of phenanthrene and benzo[a]pyrene in the soil sample.
[0038] The characteristic Raman quantitative peak of phenanthrene is 710 cm⁻¹. -1 and 1036cm -1 The characteristic Raman quantification peak of benzo[a]pyrene is at 530 cm⁻¹. -1 and 614cm -1 .
[0039] Specific Implementation Method Two: The difference between this implementation method and Specific Implementation Method One is that the ratio of the mass of the soil sample to the volume of the non-polar organic solvent in step S1 is 1g: (2~5)mL, and the non-polar organic solvent is one or more of acetone, dichloromethane, n-hexane and ethyl acetate.
[0040] The other steps are the same as in Specific Implementation Method 1.
[0041] Specific Implementation Method 3: The difference between this implementation method and Specific Implementation Method 1 or 2 is that in step S1, the soil sample containing phenanthrene and benzo[a]pyrene is passed through a 40-60 mesh sieve.
[0042] The other steps are the same as in Specific Implementation Method 1 or 2.
[0043] Specific Implementation Method Four: The difference between this implementation method and Specific Implementation Methods One to Three is that the ultrasonic power in step S1 is 200~300W, the extraction time is 10~15min, and the extraction temperature is 15~25℃.
[0044] The other steps are the same as those in Specific Implementation Methods One to Three.
[0045] Specific Implementation Method 5: The difference between this implementation method and Specific Implementation Methods 1 to 4 is that the centrifugation speed in step S2 is 3000~5000 r / min, the centrifugation time is 5~15 min, and the centrifugation temperature is 15~25℃.
[0046] The other steps are the same as those in Specific Implementation Methods One through Four.
[0047] Specific Implementation Method Six: The difference between this implementation method and Specific Implementation Methods One to Five is that the organic filter membrane in step S2 is a 0.22μm organic phase filter membrane.
[0048] The other steps are the same as those in Specific Implementation Methods 1 to 5.
[0049] Specific Implementation Method Seven: The difference between this implementation method and Specific Implementation Methods One to Six is that the volume ratio of the test solution to the nano gold sol in step S3 is 100 μL: (200~400) μL.
[0050] The other steps are the same as those in Specific Implementation Methods 1 to 6.
[0051] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One through Seven in that the nano-gold sol mentioned in step S3 is prepared using the sodium citrate reduction method, and the preparation steps are as follows:
[0052] Heat 50 mL of 0.01% chloroauric acid solution to boiling. Add 1 mL of 1% sodium citrate solution while continuously stirring with a magnetic force. After reacting for 30-40 minutes, stop heating and continue stirring while cooling to room temperature.
[0053] The other steps are the same as those in Specific Implementation Methods 1 to 7.
[0054] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One through Eight in that: the excitation wavelength of the Raman spectrometer described in step S3 is 638 nm, the laser power is 3.5~35 mW, the integration time is 5~15 s, and the spectral acquisition wavenumber range is 200~1200 cm⁻¹. -1 .
[0055] The other steps are the same as those in Specific Implementation Methods 1 to 8.
[0056] Specific Implementation Method Ten: The difference between this implementation method and Specific Implementation Methods One to Nine is: the method for establishing the standard curve described in step S4:
[0057] The concentration is 10. -2 mol / L, 10 -3 mol / L, 10 -4 mol / L, 10 -5 mol / L, 10 -6 mol / L and 10 -7 Surface-enhanced Raman spectra were collected after mixing mol / L phenanthrene standard solution and benzo[a]pyrene standard solution with gold nanoparticles, respectively. Standard curves were plotted with the peak intensity of the characteristic peak as the ordinate and the concentration of the corresponding standard solution as the abscissa, and linear regression equations were obtained.
[0058] The linear concentration ranges of phenanthrene and benzo[a]pyrene standard solutions were 10 ppm and 10 ppm, respectively. -7 ~10 -2 mol / L and 10 -7 ~10 -3 mol / L, the linear correlation coefficient R of the standard curves of the two 2 All values were greater than 0.9, and the method detection limits were all up to 10. -7 mol / L.
[0059] The other steps are the same as those in Specific Implementation Methods 1 to 9.
[0060] The beneficial effects of the present invention are verified using the following embodiments:
[0061] Example 1: A rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil, comprising the following steps:
[0062] I. Preparation of nano-gold sol:
[0063] Take 50 mL of 0.01% chloroauric acid solution and place it in a round-bottom flask. Heat to boiling and keep stirring magnetically. While stirring continuously, quickly add 1 mL of 1% sodium citrate solution and keep the reaction boiling for 35 min. After the reaction is complete, stop heating, continue stirring and cool to room temperature to obtain wine-red gold nanoparticle sol. Store at 4°C in the dark for later use.
[0064] II. Establishment of the standard curve:
[0065] (1) Preparation of standard solutions:
[0066] Using acetone as a solvent, preparations were made with a concentration of 10... -2 mol / L, 10 -3 mol / L, 10 -4 mol / L, 10 -5 mol / L, 10 - 6 mol / L and 10 -7 mol / L phenanthrene standard solution and benzo[a]pyrene standard solution;
[0067] (2) Spectral acquisition:
[0068] Take 100 μL of standard solutions at each concentration gradient, add 300 μL of the gold nanoparticle sol prepared in Example 1, mix well, and then draw the mixture into a quartz capillary tube for Raman spectrometry. Detection parameters: excitation wavelength 638 nm, laser power 17.5 mW, integration time 10 s, wavenumber scan range 200–1200 cm⁻¹. -1 The test results are as follows: Figure 1-2 As shown, the characteristic Raman peak of Feuerbach is located at a wavelength of 710 cm⁻¹. -1 1036cm -1 At this location, the characteristic Raman peak of benzo[a]pyrene is located at a wavelength of 530 cm⁻¹. -1 614cm -1 At lower concentrations, the intensity of characteristic Raman peaks gradually decreases, and the lowest detectable concentrations for phenanthrene and benzo[a]pyrene can reach 10. - 7 mol / L.
[0069] (3) Plotting the standard curve:
[0070] like Figure 3-4 As shown, 710cm of Fibre was selected respectively. -1 1036cm -1 Characteristic peak, 530 cm⁻¹ for benzo[a]pyrene. -1 614cm -1 Characteristic peaks were linearly fitted with peak intensity as the ordinate and the corresponding standard solution concentration as the abscissa to obtain the standard curve regression equation:
[0071] Fei (710cm) -1 (Quantitative peak): y = 173.76x + 1563.20, linear correlation coefficient R0 2 =0.9919;
[0072] Fei (1036 cm) -1 Quantitative peak): y = 186.79x + 1624.74, linear correlation coefficient R0 2 =0.9603;
[0073] Benzo[a]pyrene (340 cm) -1 Quantitative peak): y = 312.60x + 2364.53, linear correlation coefficient R0 2 =0.9280;
[0074] Benzo[a]pyrene (614 cm) -1 Quantitative peak): y = 364.51x + 2464.31, linear correlation coefficient R0 2 =0.9397.
[0075] The results showed that in 10 -7 ~10 -2 Within the concentration range of mol / L, the characteristic peak intensities of phenanthrene and benzo[a]pyrene showed a good linear relationship with concentration, with a linear correlation coefficient R0. 2 All values were greater than 0.9, and the method detection limits were all up to 10. -7 mol / L.
[0076] III. Detection of phenanthrene and benzo[a]pyrene in soil samples:
[0077] 1) Sample pretreatment:
[0078] Collected soil samples were ground and passed through a 50-mesh sieve. 1 g of soil sample was weighed into a centrifuge tube, 5 mL of analytical grade acetone was added, and the tube was placed in an ultrasonic cleaner and ultrasonically extracted at 23℃ and 250W for 12 min. After extraction, the centrifuge tube was placed in a centrifuge and centrifuged at 23℃ and 4000 r / min for 10 min. The supernatant was filtered through a 0.22 μm organic phase filter membrane to obtain the test solution.
[0079] 2) Raman spectroscopy:
[0080] Take 100 μL of the test solution, add 300 μL of the gold nanoparticle sol prepared in Example 1, mix well, and then use a quartz capillary to draw up the mixture. Collect surface-enhanced Raman spectra according to the same detection parameters as in step (2) above. The detection results are as follows. Figure 5 As shown;
[0081] 3) Quantitative calculation:
[0082] The peak intensities of the characteristic peaks corresponding to phenanthrene and benzo[a]pyrene in the spectrum were read and substituted into the standard curve regression equation obtained in Example 2 to calculate the concentrations of phenanthrene and benzo[a]pyrene in the test solution. Then, the actual content of phenanthrene and benzo[a]pyrene in the soil sample was calculated by combining the pretreatment dilution factor. The conversion formula is as follows:
[0083] The content of the target substance in the soil (mg / kg) = concentration of the test solution (mol / L) × volume of the extract (ml) × molar mass of the target substance (g / mol) × 1000 / mass of the soil sample (g);
[0084] Taking an actual soil sample collected from a chemical plant site as an example: 1g of soil was weighed, and after pretreatment with 5mL of acetone, the concentration of phenanthrene in the test solution was measured to be 710 cm³. -1 The characteristic peak intensity is 201,1036 cm⁻¹. -1 The characteristic peak intensity is 642; benzo[a]pyrene is 340 cm⁻¹. -1 The characteristic peak intensity is 222,614 cm⁻¹. -1 The characteristic peak intensity is 425. Substituting this into the standard curve regression equation, we get:
[0085] Concentration of phenanthrene in the test solution: Cphenanthrene = [(201-1563.2) / 173.76+(642-1624.74) / 186.79] / 2 =2.76×10 -6 mol / L.
[0086] Concentration of benzo[a]pyrene in the test solution: Cbenzo[a]pyrene = [(222-2364.53) / 312.60+(425-2464.31) / 364.51] / 2 = 1.36×10 -6 mol / L.
[0087] Based on the dilution factor in the pretreatment, the content of phenanthrene in the soil sample was calculated to be approximately 0.49 mg / kg, and the content of benzo[a]pyrene was approximately 0.34 mg / kg.
[0088] IV. Verification of Spiked Recovery:
[0089] Blank soil samples were taken, and phenanthrene and benzo[a]pyrene acetone standard solutions at low, medium, and high concentrations were added, respectively. After standing and equilibration, pretreatment and detection were performed according to the method in Example 3. Each concentration level was measured in triplicate, and the spiked recovery rate and relative standard deviation (RSD) were calculated. The results are shown in Table 1 below. The spiked recoveries of phenanthrene and benzo[a]pyrene were 78.5%~84.4%, and the relative standard deviations were 3.6%~6.8%. The method has good accuracy and precision and can meet the quantitative detection requirements of polycyclic aromatic hydrocarbons in soil samples.
[0090] Table 1
[0091]
Claims
1. A rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil, characterized in that, This method is performed in the following steps: Step S1: Sample extraction; Soil samples containing phenanthrene and benzo[a]pyrene were ground, sieved, added to a non-polar organic solvent, and extracted by ultrasonication to obtain an extract. Step S2: Sample purification; Centrifuge the extract obtained in step S1, take the supernatant, filter it through an organic filter membrane to obtain the test solution; Step S3: Sample purification; After the test solution obtained in step S1 is mixed evenly with the gold nanoparticle sol, it is placed in a Raman spectrometer to collect the surface-enhanced Raman spectrum. Step S4: Quantitative analysis; Characteristic Raman peaks of phenanthrene and benzo[a]pyrene were selected respectively, and the measured peak intensities were substituted into the pre-established standard curve to calculate the contents of phenanthrene and benzo[a]pyrene in the soil sample.
2. The rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil according to claim 1, characterized in that, The ratio of the mass of the soil sample to the volume of the non-polar organic solvent in step S1 is 1 g: (2~5) mL, and the non-polar organic solvent is one or more of acetone, dichloromethane, n-hexane and ethyl acetate.
3. The rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil according to claim 1, characterized in that, In step S1, the soil sample containing phenanthrene and benzo[a]pyrene is passed through a 40-60 mesh sieve.
4. The rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil according to claim 1, characterized in that, In step S1, the ultrasonic power is 200~300W, the extraction time is 10~15min, and the extraction temperature is 15~25℃.
5. The rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil according to claim 1, characterized in that, In step S2, the centrifugation speed is 3000~5000 r / min, the centrifugation time is 5~15 min, and the centrifugation temperature is 15~25℃.
6. The rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil according to claim 1, characterized in that, In step S2, the organic filter membrane is a 0.22 μm organic phase filter membrane.
7. The rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil according to claim 1, characterized in that, The volume ratio of the test solution to the gold nanoparticle sol in step S3 is 100 μL: (200~400) μL.
8. The rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil according to claim 1, characterized in that, The gold nanoparticle sol mentioned in step S3 is prepared by sodium citrate reduction method, and the preparation steps are as follows: Heat 50 mL of 0.01% chloroauric acid solution to boiling. Add 1 mL of 1% sodium citrate solution while continuously stirring with a magnetic force. After reacting for 30-40 minutes, stop heating and continue stirring while cooling to room temperature.
9. A rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil according to claim 1, characterized in that, The Raman spectrometer described in step S3 has an excitation wavelength of 638 nm, a laser power of 3.5–35 mW, an integration time of 5–15 s, and a spectral acquisition wavenumber range of 200–1200 cm⁻¹. -1 .
10. A rapid detection method for polycyclic aromatic hydrocarbons phenanthrene and benzo[a]pyrene in soil according to claim 1, characterized in that, The method for establishing the standard curve described in step S4: The concentration is 10. -2 mol / L, 10 -3 mol / L, 10 -4 mol / L, 10 -5 mol / L, 10 -6 mol / L and 10 -7 Surface-enhanced Raman spectra were collected after mixing mol / L phenanthrene standard solution and benzo[a]pyrene standard solution with gold nanoparticles, respectively. Standard curves were plotted with the peak intensity of the characteristic peak as the ordinate and the concentration of the corresponding standard solution as the abscissa, and linear regression equations were obtained.