A method for simultaneously detecting sulfide odor-causing substances in overlying water, interstitial water and sediment

Abstract

The present invention relates to the field of water treatment technology, and discloses a method for simultaneously detecting sulfide odor-causing substances in overlying water, interstitial water and sediments. The present invention discloses a method for simultaneously determining a variety of sulfide odor-causing substances in overlying water, interstitial water and sediments of a rainwater pipe by using a HS-SPME-GC / MS method, which has the advantages of simple operation and accuracy. At present, there are few studies on the simultaneous analysis of odor-causing substances in overlying water, interstitial water and sediments in water bodies, and especially there are few studies on the detection of odor-causing substances in interstitial water. The technical solution of the present invention fills this gap, and simultaneously quantitatively analyzes sulfide odor-causing substances in multiple phases in a rainwater pipe, which is conducive to a comprehensive understanding of the odor pollution status of the rainwater pipe and the migration process and diffusion mechanism of sulfide substances between overlying water, interstitial water and sediments.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, and in particular to a method for simultaneously detecting sulfide odor-causing substances in overlying water, interstitial water and sediment. Background Art

[0002] Odor pollution in urban polluted water bodies has become an increasingly serious environmental problem. Among them, direct discharge of rainwater pipe pollution is one of the important causes of river odor. Odor-causing organic matter has the dual properties of sensory pollution and chemical pollution. It not only affects human health and damages the respiratory and nervous systems, but also seriously threatens the quality of urban water environment and ecological balance. Among the various odorous substances, sulfide substances are a class of widely existing odorous substances with high olfactory activity and low olfactory threshold, which causes the water body to have different degrees of rancid odor.

[0003] At present, the main focus of the determination technology of sulfide substances in water bodies is on the overlying water. The Chinese invention application with application number 202210578173.6 discloses a method for determining a variety of sulfide odor substances in water using headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC / MS). However, this method can only analyze sulfide odor substances in water samples.

[0004] Sediments are the main component of water environments such as drainage pipes. Sulfur-containing organic matter in them produces a large amount of sulfide substances in the process of geobiochemical cycles. According to literature reports, the Taihu Lake water crisis in 2007 was mainly caused by excessive levels of sulfide substances such as dimethyl trisulfide and dimethyl disulfide in the water, which caused the water to stink. In addition to a part of the sulfide substances produced by algae decay and decomposition, most of the sulfide substances come from the diffusion of sediments and release into the overlying water. Therefore, it is very important to master the environmental information of sulfide substances in sediments and interstitial water.

[0005] The Chinese invention application with application number 202110328804.4 discloses a detection method for dimethyl disulfide and dimethyl trisulfide in water bodies using a high performance liquid chromatography elution system-gas chromatography-mass spectrometry technology. In addition, diethyl sulfide, diethyl trisulfide, methyl propyl sulfide, isopropyl methyl sulfide, ethyl n-propyl sulfide, dipropyl sulfide, isopropyl sulfide, diphenyl sulfide, etc. are all important odorous substances in water bodies. In addition, sulfide odor-causing substances are volatile organic sulfurs, which may cause volatilization and loss of target substances during the mobile phase elution process, making it difficult to accurately quantify sulfide substances. Therefore, it is of great significance to improve the extraction and quantification methods of various sulfide odor-causing substances in water bodies and ensure the accuracy and reliability of the quantitative results of odor-causing substances, so as to better understand the types and concentration distribution of odor-causing substances in water bodies and control water odor pollution.

[0006] With the in-depth development of research work, simply quantifying the occurrence of some sulfide odor-causing substances in overlying water can no longer meet the needs of fully and accurately obtaining environmental geochemical information of sulfide substances at the sediment-water interface. The global element cycle research requires accurate and rapid extraction of sulfide substances in overlying water, interstitial water and sediments. At present, the technical bottleneck of extraction and detection of various sulfide substances in interstitial water and sediments has become a key factor restricting the research and development of sulfide odor-causing substances. Mastering its rapid and accurate pretreatment methods and improving the detection methods of major sulfide substances in water bodies will lay an important foundation for in-depth research on the diffusion mechanism of sulfide odor-causing substances at the interface between rainwater pipe sediments and water, and has scientific and technological support significance for scientifically guiding the treatment of odorous water bodies. Summary of the invention

[0007] The purpose of the present invention is to provide a method for simultaneously detecting sulfide odor-causing substances in overlying water, interstitial water and sediment based on the above technical problems.

[0008] The technical solution of the present invention:

[0009] In order to achieve the above object, the first aspect of the present invention provides a method for simultaneously detecting sulfide odor-causing substances in overlying water, interstitial water and sediment, the method comprising the following steps:

[0010] (1) Collect overlying water samples, interstitial water samples, and sediment samples from the rainwater pipe respectively, and pre-treat them respectively to obtain pre-treated overlying water samples, pre-treated interstitial water samples, and pre-treated sediment samples respectively;

[0011] (2) respectively performing extraction treatment on the pretreated overlying water sample, the pretreated interstitial water sample, and the pretreated sediment sample to enrich the sulfide odor-causing substances in the samples, and obtaining an overlying water sample, an interstitial water sample, and a sediment sample, respectively;

[0012] (3) connecting the overlying water sample, the interstitial water sample, and the sediment sample to a gas chromatograph-mass spectrometer for detection, and operating the method in SIM mode to obtain a mass spectrum of sulfide odor-causing substances in the overlying water sample, a mass spectrum of sulfide odor-causing substances in the interstitial water sample, and a mass spectrum of sulfide odor-causing substances in the sediment sample, respectively;

[0013] (4) According to the mass spectrum of the sulfide odor-causing substances in the overlying water sample, the peak areas of the 12 sulfide odor-causing substances and the linear equations of the 12 sulfide odor-causing substances in the overlying water sample are obtained to determine the concentrations of the 12 sulfide odor-causing substances in the overlying water sample; according to the mass spectrum of the sulfide odor-causing substances in the interstitial water sample and the linear equations of the 12 sulfide odor-causing substances in the interstitial water sample, the concentrations of the 12 sulfide odor-causing substances in the interstitial water sample are determined; according to the mass spectrum of the sulfide odor-causing substances in the sediment sample and the linear equations of the 12 sulfide odor-causing substances in the sediment sample, the concentrations of the 12 sulfide odor-causing substances in the sediment sample are determined;

[0014] The 12 sulfide odor-causing substances are methyl ethyl sulfide, isopropyl methyl sulfide, diethyl sulfide, methyl propyl sulfide, dimethyl disulfide, isopropyl sulfide, ethyl n-propyl sulfide, dipropyl sulfide, diethyl disulfide, dimethyl trisulfide, diethyl trisulfide and diphenyl sulfide.

[0015] According to a particularly preferred embodiment, in step (1), the specific method of the pretreatment is as follows:

[0016] 10 mL of the overlying water sample was directly measured and placed in headspace bottle I. 10 mL of interstitial water was collected using a soil pore water sampler and placed in headspace bottle II. Subsequently, 3.65 g of NaCl was added to headspace bottles I and II to dissolve to ensure that the NaCl concentration in the system was saturated sodium chloride. 2.00 g of the sediment sample was weighed and placed in headspace bottle III. 10 mL of saturated NaCl solution was added, and then an appropriate amount of phosphoric acid was added to adjust the pH to ≤ 2.

[0017] Further preferably, in step (2), the extraction treatment is performed using an activated carbon / polydimethylsiloxane probe with a fiber material of 75 μm and 1 cm, and is aged at 250° C. for 10 min before use.

[0018] Preferably, in step (2), the extraction treatment is carried out under stirring, and the conditions of the extraction treatment meet the following conditions: temperature is 65° C., rotation speed is 200 r / min, and time is 30 min.

[0019] According to a particularly preferred embodiment, in step (3), the operating conditions in the gas chromatograph mass spectrometer are as follows:

[0020] Chromatographic column: Rtx-5MS capillary column, 30 m × 0.25 μm × 0.25 μm;

[0021] Carrier gas type: Helium, 99.999%;

[0022] Flow rate: 1.93 mL / min;

[0023] Column temperature: the initial temperature was 32°C and maintained at the initial temperature for 5 min, then the temperature was increased to 110°C at 8°C / min and maintained at 110°C for 2 min, then the temperature was increased to 270°C at 20°C / min and maintained for 8 min;

[0024] Inlet temperature: 250°C;

[0025] Analysis time: 2min;

[0026] Injection method: splitless injection;

[0027] EI source electron energy: 70eV;

[0028] Ion source temperature: 230°C;

[0029] Interface temperature: 260℃;

[0030] Acquisition mode: full scan for qualitative analysis, ion mode for quantitative analysis;

[0031] Solvent delay: 2.05 min.

[0032] Technical effects of the present invention:

[0033] (1) The present invention discloses a method for simultaneously determining multiple sulfide odor-causing substances in the overlying water, interstitial water and sediment of a rainwater pipe using the HS-SPME-GC / MS method, which has the advantages of simple operation and accuracy. At present, there are few studies on the simultaneous analysis of odor-causing substances in overlying water, interstitial water and sediment in water bodies, especially few studies on the detection of odor-causing substances in interstitial water. The technical solution of the present invention fills this gap and simultaneously quantitatively analyzes sulfide odor-causing substances in multiple phases in rainwater pipes, which is conducive to a comprehensive understanding of the odor pollution status of rainwater pipes and the migration process and diffusion mechanism of sulfide substances between overlying water-interstitial water-sediment.

[0034] (2) The method provided by the present invention can simultaneously determine methyl ethyl sulfide, isopropyl methyl sulfide, diethyl sulfide, methyl propyl sulfide, dimethyl disulfide, isopropyl sulfide, ethyl n-propyl sulfide, dipropyl sulfide, diethyl disulfide, dimethyl trisulfide, diethyl trisulfide and diphenyl sulfide, among which diethyl trisulfide is the first odor-causing substance to be quantitatively determined in a water environment. At present, there is no report on the simultaneous determination of the above-mentioned multiple sulfide odor-causing substances using a single method. The technical solution of the present invention fills this gap and quantitatively analyzes the above-mentioned multiple sulfides in the rainwater pipes at one time, greatly improving the detection efficiency.

[0035] (3) The present invention uses the headspace solid phase microextraction method to enrich 12 sulfide odor-causing substances. The operation is simple, easy to automate, and does not require solvents. In addition, the selectivity and sensitivity of the target substance to be measured are related to the coating polarity of the extraction fiber. The fiber material of the probe used in the present invention is 75μm and 1cm CAR / PDMS. CAR / PDMS uses a strong adsorption porous coating and has the advantages of high sensitivity and high accuracy. It has a high-fold enrichment performance for low molecular weight mixtures and can quickly extract a variety of sulfide odor-causing substances in water samples and sediment samples.

[0036] (4) The present invention uses the HS-SPME-GC / MS method to quickly and synchronously detect 12 sulfide odor-causing substances in water. The detection range of odor-causing substances in overlying water or interstitial water is 50~1000ng / L, and the detection range of odor-causing substances in sediment is 65.5~1000ng / g. The method of the present invention has high sensitivity, good reproducibility and a wide detection range. It can be widely used to detect the dynamic changes of various sulfide odor-causing substances in rainwater pipes in different seasons and with different pollution degrees. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the mass spectrum of 12 sulfide odor-causing substances;

[0038] Figure 2 : is a graph showing the concentration of 12 sulfide odor-causing substances in the rainwater pipe overlying water sample detected by the embodiment of the present invention, Figure 2 It can be seen that the sulfide odor-causing substances in the overlying water samples of the rainwater pipes are mainly isopropyl sulfide and diphenyl sulfide;

[0039] Figure 3 Graph showing the concentrations of 12 sulfide odor-causing substances in interstitial water samples detected by the present invention. Figure 3 It can be seen that the sulfide odor-causing substances in the interstitial water samples of rainwater pipes are mainly methyl ethyl sulfide, diethyl sulfide, diethyl trisulfide, and diphenyl sulfide;

[0040] Figure 4 : is a graph showing the concentration results of 12 sulfide odor-causing substances in sediment samples detected by the embodiment of the present invention, Figure 4 It can be seen that the sulfide odor-causing substances in the sediment samples are mainly diethyl sulfide, dimethyl trisulfide, diethyl trisulfide and diphenyl sulfide;

[0041] Figure 5 : is a graph showing the total concentration of 12 sulfide odor-causing substances in the rainwater pipe overlying water sample, interstitial water sample, and sediment sample detected by the embodiment of the present invention, Figure 5It can be seen that the total concentration of 12 sulfide odor-causing substances in overlying water samples was 3.08 μg / L, 0.45 μg / L in interstitial water samples, and 0.923 μg / g in sediment samples. DETAILED DESCRIPTION

[0042] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0043] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, the raw materials are all commercially available.

[0044] Preparation Example

[0045] S1: Prepare mixed standard stock solution.

[0046] Specifically, weigh 25 mg of methyl ethyl sulfide, 25 mg of isopropyl methyl sulfide, 25 mg of diethyl sulfide, 25 mg of methyl propyl sulfide, 25 mg of dimethyl disulfide, 25 mg of isopropyl sulfide, 25 mg of ethyl n-propyl sulfide, 25 mg of dipropyl sulfide, 25 mg of diethyl disulfide, 25 mg of dimethyl trisulfide, 25 mg of diethyl trisulfide, and 25 mg of diphenyl sulfide and add them to a beaker, then add methanol (chromatographic grade), transfer the mixture to a volumetric flask, make up to 25 mL with methanol (chromatographic grade) to prepare a mixed standard stock solution with a concentration of 1 g / L.

[0047] S2: Prepare mixed standard working solution.

[0048] Specifically, 50 μL of the mixed standard stock solution was measured, and the volume was adjusted to 50 mL with methanol (chromatographic grade) to prepare a mixed standard working solution A with a concentration of 1 mg / L; 100 μL of the mixed standard working solution A was measured, and the volume was adjusted to 10 mL with methanol (chromatographic grade) to prepare a mixed standard working solution B with a concentration of 10 μg / L.

[0049] S3: Prepare a mixed standard working solution of overlying water (or prepare a mixed standard working solution of interstitial water).

[0050] Specifically, 0.05 mL, 0.10 mL, 0.20 mL, 0.40 mL, 0.60 mL, 0.80 mL, and 1.00 mL of the mixed standard working solution B were measured and placed in headspace bottle 1, headspace bottle 2, headspace bottle 3, headspace bottle 4, headspace bottle 5, headspace bottle 6, and headspace bottle 7, respectively, and then diluted to 10 mL with saturated NaCl solution to prepare mixed standard working solutions with concentration gradients of 50, 100, 200, 400, 600, 800, and 1000 ng / L, respectively.

[0051] S4: Prepare a mixed standard working solution of sediment.

[0052] Specifically, 2.00 g of quartz sand (the particle size of the quartz sand is 40-60 mesh, and it needs to be tested before use to confirm that the concentration of the target compound is lower than the method detection limit) is added to the headspace bottle 1 to the headspace bottle 7, respectively, and then 10.0000 mL of saturated NaCl solution is added to the headspace bottle 1, 12.5 μL of the mixed standard solution B and 9.9875 mL of saturated NaCl solution are added to the headspace bottle 2, 25.0 μL of the mixed standard solution B and 9.9750 mL of saturated NaCl solution are added to the headspace bottle 3, and 50.0 μL of the mixed standard solution B and 9.9750 mL of saturated NaCl solution are added to the headspace bottle 4. L of the mixed standard liquid B and 9.9500mL of saturated NaCl solution, add 100.0μL of the mixed standard liquid B and 9.9000mL of saturated NaCl solution to the headspace bottle 5, add 150.0μL of the mixed standard liquid B and 9.8500mL of saturated NaCl solution to the headspace bottle 6, add 200.0μL of the mixed standard liquid B and 9.8000mL of saturated NaCl solution to the headspace bottle 7, seal them respectively immediately, configure them into mixed standard working solutions of sediments with concentrations of sulfide odor-causing substances of 65.5, 125, 250, 500, 750, and 1000 ng / g, respectively, and then place them on an oscillator at the same time, oscillate at a frequency of 150 times / min for 10 min, and test them.

[0053] S5: Prepare a standard curve for overlying water samples, a standard curve for interstitial water samples, and a standard curve for sediment samples.

[0054] Specifically, the above samples were detected by gas chromatography-mass spectrometry (operating conditions are shown below), and the mixed standard working solution of the water sample was analyzed in SCAN mode to obtain the mass spectra of 12 sulfide odor-causing substances (such as Figure 1), to determine the peak time, target ions and reference ions of methyl ethyl sulfide, isopropyl methyl sulfide, diethyl sulfide, methyl propyl sulfide, dimethyl disulfide, isopropyl sulfide, ethyl n-propyl sulfide, dipropyl sulfide, diethyl disulfide, dimethyl trisulfide, diethyl trisulfide and diphenyl sulfide, as shown in Table 1;

[0055] According to the elution time, target ion and reference ion of each sulfide odor-causing substance, the SIM mode operation method was established (as shown in Table 2) to determine the quantitative method of 12 sulfide odor-causing substances in overlying water samples, interstitial water samples and sediment samples; and in the SIM mode, the mixed standard working solution of overlying water samples, the mixed standard working solution of interstitial water samples and the mixed standard working solution of sediment samples were analyzed respectively to determine the mass concentration-peak area relationship of methyl ethyl sulfide, isopropyl methyl sulfide, diethyl sulfide, methyl propyl sulfide, dimethyl disulfide, isopropyl sulfide, ethyl n-propyl sulfide, dipropyl sulfide, diethyl disulfide, dimethyl trisulfide, diethyl trisulfide and diphenyl sulfide in overlying water samples, interstitial water samples and sediment samples respectively, and the linear regression equation of the above 12 sulfide odor-causing substances was obtained, and the signal-to-noise ratio S / N = 3 Calculation method detection limit. The linear equations, linear ranges and method detection limits of 12 sulfide odor-causing substances in overlying water samples and interstitial water samples are shown in Table 3. The linear equations, linear ranges and method detection limits of 12 sulfide odor-causing substances in sediment samples are shown in Table 4.

[0056] Wherein, the operating conditions of the gas chromatograph mass spectrometer are as follows:

[0057] Chromatographic column: Rtx-5MS capillary column, 30 m × 0.25 μm × 0.25 μm;

[0058] Carrier gas type: Helium, 99.999%;

[0059] Flow rate: 1.93 mL / min;

[0060] Column temperature: the initial temperature was 32°C and maintained at the initial temperature for 5 min, then the temperature was increased to 110°C at 8°C / min and maintained at 110°C for 2 min, then the temperature was increased to 270°C at 20°C / min and maintained for 8 min;

[0061] Inlet temperature: 250°C;

[0062] Analysis time: 2min;

[0063] Injection method: splitless injection;

[0064] EI source electron energy: 70eV;

[0065] Ion source temperature: 230°C;

[0066] Interface temperature: 260℃;

[0067] Acquisition mode: full scan for qualitative analysis, ion mode for quantitative analysis;

[0068] Solvent delay: 2.05 min.

[0069] Table 1

[0070]

[0071] Table 2

[0072]

[0073] Table 3

[0074]

[0075] Table 4

[0076]

[0077] As shown in Tables 3 and 4, the concentrations of various sulfide odor-causing substances in overlying water samples and interstitial water samples were within the linear range of 50-1000 ng / L, and the concentrations of various sulfide odor-causing substances in sediment samples were within the linear range of 65.5-1000.0 ng / g, all of which showed good linearity, with a correlation coefficient (R 2 ) were all above 0.9900, the detection limits of the overlying water samples and interstitial water samples were 3-39 ng / L, and the detection limits of the sediment samples were 13.6-66.4 ng / g.

[0078] S6: The external standard method was used to quantify the sulfide substances. The recovery rate and relative standard deviation of the sulfide odor-causing substances in the overlying water samples and interstitial water samples were analyzed. The results are shown in Table 5. The recovery rate and relative standard deviation of the sulfide odor-causing substances in the sediment samples were analyzed. The results are shown in Table 6.

[0079] Table 5

[0080]

[0081] As shown in Table 5, for water samples, the average recoveries of the 12 sulfides with ultrapure water and raw water as matrices under the second concentration gradient of the standard curve ranged from 81.6% to 107.4% and 84.3% to 104.9%, respectively, and the relative standard deviations ranged from 5.6% to 7.9% and 3.2% to 13.4%, respectively. It can be seen that this method can be used for the determination of sulfides in water.

[0082] Table 6

[0083]

[0084] As shown in Table 6, for sediment samples, the average recoveries of the 12 sulfides with quartz sand and sediment as matrices under the second concentration gradient of the standard curve ranged from 80.83.2% to 110.6% and 86.1% to 107.9%, respectively, and the relative standard deviations ranged from 5.3% to 17.2% and 5.5% to 17.4%, respectively, which all met the quantitative requirements. It can be seen that this method can be used for the determination of sulfides in sediments.

[0085] S7: Determine the concentration of sulfide odor-causing substances in overlying water, interstitial water and sediment:

[0086] 10 mL of the overlying water sample was measured and placed in a headspace bottle I, and then 3.65 g of NaCl was added to ensure that the NaCl in the headspace bottle I was in a saturated concentration state to obtain sample I. The established quantitative method for 12 sulfide odor-causing substances in water samples was used to run the sample in SIM mode, and the prepared standard curves of the overlying water sample and the interstitial water sample were used for data analysis to obtain the concentration of sulfide odor-causing substances in the overlying water;

[0087] A soil pore water sampler was used to collect 10 mL of interstitial water samples in the sediment, and the samples were placed in a headspace bottle II. 3.65 g of NaCl was added to ensure that the NaCl in the headspace bottle II was in a saturated concentration state, and sample II was obtained. The established quantitative method for 12 sulfide odor-causing substances in the overlying water samples and interstitial water samples was used in the SIM mode, and the data were analyzed using the prepared standard curves of the overlying water and interstitial water samples to obtain the concentration of sulfide odor-causing substances in the interstitial water.

[0088] Weigh 2.00 g of sediment sample and place it in headspace bottle III, then add 10 mL of saturated NaCl solution, and adjust the pH value to ≤ 2 with phosphoric acid to obtain sample III. Run the established quantitative method for 12 sulfide odorants in sediments in SIM mode, and use the prepared standard curve of sediment samples for data analysis to obtain the measured concentration of sulfide odorants in sediments. The next step is data processing;

[0089] Concentration of sulfide odor-causing substances in sediments c s (ng / g)=(c1×2g–2g×w×c2) / [2g×(100%-w)], where c1 is the concentration of sulfide odor-causing substances in the sediment containing interstitial water, measured in ng / g; c2 is the concentration of sulfide odor-causing substances in the interstitial water, measured in ng / L; and w is the water content of the sediment, measured in %.

[0090] The calculation formula for the moisture content w of the sediment is as follows, and the determination method includes: drying the covered container and the lid at 105±5°C for 1h, cooling, covering with the lid, and cooling in a desiccator for 45min, and determining the mass of the covered container, which is recorded as m0 (accurate to 0.01g);

[0091] Transfer 10-20g of sediment to the above container, cover the container, measure the total mass, record it as m1 (accurate to 0.01g), then transfer it to an oven, remove the container cover, dry it at 105 ± 5℃ to constant weight, cover the container cover, place it in a desiccator to cool for 45min, take it out and immediately measure the total mass, record it as m2 (accurate to 0.01g);

[0092] The calculation formula is: w = (m1-m0) / (m2-m0) × 100%.

[0093] Example 1

[0094] (1) In mid-January 2024, samples of overlying water, interstitial water and sediment were collected from the rainwater pipes of a city in the Pearl River Delta and pretreated respectively to obtain pretreated interstitial water samples, pretreated overlying water samples and pretreated sediment samples, and the measured concentrations of sulfide odor-causing substances in the overlying water, the measured concentrations of sulfide odor-causing substances in the interstitial water and the measured concentrations of sulfide odor-causing substances in the sediment were obtained respectively.

[0095] Specifically, 10 mL of the overlying water sample was measured and placed in a headspace bottle 1, and then 3.65 g of NaCl was added to ensure that the NaCl in the headspace bottle 1 was in a saturated concentration state, to obtain a pretreated overlying water sample;

[0096] Then, a 10 mL interstitial water sample was collected using a soil pore water sampler and placed in a headspace bottle II, and 3.65 g of NaCl was added to ensure that the NaCl in the headspace bottle II was in a saturated concentration state, thereby obtaining a pretreated interstitial water sample;

[0097] Weigh 2.00 g of sediment sample and place it in headspace bottle III, then add 10 mL of saturated NaCl solution, and adjust the pH value to ≤ 2 with phosphoric acid to obtain a pretreated sediment sample.

[0098] (2) Extracting the pretreated overlying water sample, the pretreated interstitial water sample, and the pretreated sediment sample respectively to enrich the sulfide odor-causing substances in the samples, thereby obtaining an overlying water sample, an interstitial water sample, and a sediment sample respectively.

[0099] The extraction treatment uses an activated carbon / polydimethylsiloxane (CAR / PDMS) probe with a fiber material of 75 μm and 1 cm, and is aged at 250° C. for 10 min before use; the extraction treatment is carried out under stirring, and the conditions of the extraction treatment meet the following requirements: temperature of 65° C., rotation speed of 200 r / min, and time of 30 min.

[0100] (3) The overlying water sample, the interstitial water sample, and the sediment sample were connected to a gas chromatograph-mass spectrometer for detection, and the quantitative method for detecting 12 sulfide odor-causing substances in the overlying water sample and the interstitial water sample established in the preparation example was used for the detection (as shown in Table 2), thereby obtaining the mass spectra of the sulfide odor-causing substances in the overlying water sample, the mass spectra of the sulfide odor-causing substances in the interstitial water sample, and the mass spectra of the sulfide odor-causing substances in the sediment sample, respectively.

[0101] Wherein, the operating conditions of the gas chromatograph mass spectrometer are as follows:

[0102] Chromatographic column: Rtx-5MS capillary column, 30 m × 0.25 μm × 0.25 μm;

[0103] Carrier gas type: Helium, 99.999%;

[0104] Flow rate: 1.93 mL / min;

[0105] Column temperature: the initial temperature was 32°C and maintained at the initial temperature for 5 min, then the temperature was increased to 110°C at 8°C / min and maintained at 110°C for 2 min, then the temperature was increased to 270°C at 20°C / min and maintained for 8 min;

[0106] Inlet temperature: 250°C;

[0107] Analysis time: 2min;

[0108] Injection method: splitless injection;

[0109] EI source electron energy: 70eV;

[0110] Ion source temperature: 230°C;

[0111] Interface temperature: 260℃;

[0112] Acquisition mode: full scan for qualitative analysis, ion mode for quantitative analysis;

[0113] Solvent delay: 2.05 min.

[0114] (4) According to the above mass spectra, the peak areas of 12 sulfide odor-causing substances in the overlying water samples, interstitial water samples and sediment samples were obtained (as shown in Table 7). Based on the peak areas, the linear equations of 12 sulfide odor-causing substances in the overlying water samples in the preparation example were used to process the data (as shown in Table 3) to obtain the concentrations of sulfide odor-causing substances in the overlying water (as shown in Table 3). Figure 2 The linear equations of 12 sulfide odor-causing substances in the interstitial water samples in the preparation example were used to process the data (as shown in Table 3) to obtain the concentration of sulfide odor-causing substances in the interstitial water (as shown in Table 3). Figure 3 The linear equations of the 12 sulfide odor-causing substances in the sediment in the preparation example were used to process the data (as shown in Table 4) to obtain the concentrations of sulfide odor-causing substances in the sediment (as shown in Table 4). Figure 4 as shown).

[0115] Table 7

[0116]

[0117] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for simultaneously detecting sulfide odor-causing substances in overlying water, interstitial water and sediment, characterized in that: The method comprises the following steps: (1) collecting overlying water samples, interstitial water samples, and sediment samples from the rainwater pipe respectively, and pre-treating them respectively to obtain pre-treated overlying water samples, pre-treated interstitial water samples, and pre-treated sediment samples respectively; (2) respectively extracting the pretreated overlying water sample, the pretreated interstitial water sample, and the pretreated sediment sample to enrich the sulfide odor-causing substances in the samples, and obtaining an overlying water sample, an interstitial water sample, and a sediment sample, respectively; (3) connecting the overlying water sample, the interstitial water sample, and the sediment sample to a gas chromatograph-mass spectrometer for detection, and operating the method in SIM mode to obtain a mass spectrum of sulfide odor-causing substances in the overlying water sample, a mass spectrum of sulfide odor-causing substances in the interstitial water sample, and a mass spectrum of sulfide odor-causing substances in the sediment sample, respectively; (4) according to the mass spectrum of the sulfide odor-causing substances in the overlying water sample, the peak areas of the 12 sulfide odor-causing substances and the linear equations of the 12 sulfide odor-causing substances in the overlying water sample are obtained, and the concentrations of the 12 sulfide odor-causing substances in the overlying water sample are determined; according to the mass spectrum of the sulfide odor-causing substances in the interstitial water sample and the linear equations of the 12 sulfide odor-causing substances in the interstitial water sample, the concentrations of the 12 sulfide odor-causing substances in the interstitial water sample are determined; according to the mass spectrum of the sulfide odor-causing substances in the sediment sample and the linear equations of the 12 sulfide odor-causing substances in the sediment sample, the concentrations of the 12 sulfide odor-causing substances in the sediment sample are determined; The 12 sulfide odor-causing substances are methyl ethyl sulfide, isopropyl methyl sulfide, diethyl sulfide, methyl propyl sulfide, dimethyl disulfide, isopropyl sulfide, ethyl n-propyl sulfide, dipropyl sulfide, diethyl disulfide, dimethyl trisulfide, diethyl trisulfide and diphenyl sulfide; In step (1), the specific method of the pretreatment is as follows: 10 mL of the overlying water sample was directly measured and placed in headspace bottle I. 10 mL of interstitial water was collected using a soil pore water sampler and placed in headspace bottle II. Subsequently, 3.65 g of NaCl was added to headspace bottles I and II to dissolve to ensure that the concentration of NaCl in the system was saturated sodium chloride. 2.00 g of the sediment sample was weighed and placed in headspace bottle III. 10 mL of saturated NaCl solution was added, and then an appropriate amount of phosphoric acid was added to adjust the pH to ≤ 2. In step (2), the extraction treatment is carried out using an activated carbon / polydimethylsiloxane probe with a fiber material of 75 μm and 1 cm, and is aged at 250° C. for 10 min before use; In step (2), the extraction process is carried out under stirring, and the conditions of the extraction process meet the following conditions: temperature is 65° C., rotation speed is 200 r / min, and time is 30 min; In step (3), the operating conditions in the gas chromatograph mass spectrometer are as follows: Chromatographic column: Rtx-5MS capillary column, 30m×0.25μm×0.25μm; Carrier gas type: Helium, 99.999%; Flow rate: 1.93 mL / min; Column temperature: the initial temperature was 32°C and maintained at the initial temperature for 5 min, then the temperature was increased to 110°C at 8°C / min and maintained at 110°C for 2 min, then the temperature was increased to 270°C at 20°C / min and maintained for 8 min; Inlet temperature: 250°C; Analysis time: 2min; Injection method: splitless injection; EI source electron energy: 70eV; Ion source temperature: 230°C; Interface temperature: 260℃; Acquisition mode: full scan for qualitative analysis, ion mode for quantitative analysis; Solvent delay: 2.05 min.

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