阅读说明：本技术 同时测定土壤中多环芳烃和多氯联苯的方法 (Method for simultaneously measuring polycyclic aromatic hydrocarbon and polychlorinated biphenyl in soil ) 是由 车凯 郁金星 刘克成 韩忠阁 牛向楠 侯海萍 宫云茜 于 2020-05-21 设计创作，主要内容包括：本发明提供了一种同时测定土壤中多环芳烃和多氯联苯的方法,包括对土壤样品进行除去异物、提取、萃取和小柱净化处理,得到待测样品溶液；利用气相色谱-质谱仪检测空白试样；利用气相色谱-质谱仪检测待测样品溶液；用待测样品溶液检测结果扣除空白试样检测结果,即得。本发明首先对待检测样品进行除去异物、提取、萃取和小柱净化处理,然后采用气相色谱-质谱仪法检测,可以同时分析土壤中16种PHAs和18种PCBs,且该方法高效、灵敏、检测限低、检测周期短,提高检测的准确定和实效性。(The invention provides a method for simultaneously measuring polycyclic aromatic hydrocarbon and polychlorinated biphenyl in soil, which comprises the steps of removing foreign matters, extracting and purifying a soil sample by a small column to obtain a sample solution to be measured; detecting a blank sample by using a gas chromatography-mass spectrometer; detecting a sample solution to be detected by using a gas chromatography-mass spectrometer; and deducting the detection result of the blank sample by using the detection result of the sample solution to be detected. The method firstly removes foreign matters, extracts and purifies the sample to be detected by a small column, then adopts a gas chromatography-mass spectrometer method for detection, can simultaneously analyze 16 PHAs and 18 PCBs in the soil, has high efficiency, sensitivity, low detection limit and short detection period, and improves the accurate determination and effectiveness of the detection.)

1. A method for simultaneously measuring polycyclic aromatic hydrocarbon and polychlorinated biphenyl in soil is characterized in that: comprises the following steps

a. Pretreating a soil sample, wherein the pretreatment comprises the steps of removing foreign matters, extracting and purifying by a small column to obtain a sample solution to be detected;

b. quartz sand is selected as a blank sample, and the blank sample is detected by a gas chromatography-mass spectrometer;

c. detecting a sample solution to be detected by using a gas chromatography-mass spectrometer;

d. and deducting the detection result of the blank sample from the detection result of the sample solution to be detected.

2. The method for simultaneously determining polycyclic aromatic hydrocarbons and polychlorinated biphenyls (PCBs) in soil as claimed in claim 1, wherein: the step a comprises the following steps:

a1, foreign matter removal: removing foreign matters from the soil sample, and fully and uniformly mixing; adding anhydrous sodium sulfate, and stirring until the sample to be detected is in a quicksand shape; refrigerating at below 4 deg.C for 48 hr;

a2, extracting: refrigerating, adding polycyclic aromatic hydrocarbon substitute, and 25 μ L of tetrachloro-m-xylene; then adding n-hexane and acetone with the same volume for extraction;

a3, extraction: extracting by adopting any one of Soxhlet extraction, pressurized fluid extraction or ultrasonic extraction;

a4, purifying by a small column: pretreating the small column; transferring the liquid obtained in the step a3 to a small column, washing a concentration vessel with n-hexane for three times, and transferring all washing liquid into the small column; adding 5mL of dichloromethane-n-hexane mixed solvent for elution; continuously adding 5mL of dichloromethane-n-hexane mixed solvent, collecting all eluent, and concentrating the eluent; and adding an internal standard substance to obtain a sample solution to be detected.

3. The method for simultaneously determining polycyclic aromatic hydrocarbons and polychlorinated biphenyls (PCBs) in soil as claimed in claim 2, wherein: in the step a2, the liquid level of the n-hexane and the acetone is 2cm higher than the surface of the soil sample.

4. The method for simultaneously determining polycyclic aromatic hydrocarbons and polychlorinated biphenyls (PCBs) in soil as claimed in claim 2, wherein: in step a3, the extraction method is ultrasonic extraction.

5. The method for simultaneously determining polycyclic aromatic hydrocarbons and polychlorinated biphenyls (PCBs) in soil as claimed in claim 4, wherein: the conditions of the ultrasonic extraction are as follows: the extracting agent is n-hexane and acetone in a volume ratio of 1:1, the ultrasonic frequency is 600W, and the temperature is 25 ℃.

6. The method for simultaneously determining polycyclic aromatic hydrocarbons and polychlorinated biphenyls (PCBs) in soil as claimed in claim 4, wherein: the extraction time of the ultrasonic extraction is 15 min.

7. The method for simultaneously determining polycyclic aromatic hydrocarbons and polychlorinated biphenyls (PCBs) in soil as claimed in claim 4, wherein: the extraction times of the ultrasonic extraction are 4 times.

8. The method of claim 2The method for simultaneously measuring the polycyclic aromatic hydrocarbon and the polychlorinated biphenyl in the soil is characterized by comprising the following steps: in step a4, the internal standard substance is naphthalene-d 8, acenaphthylene-d 10, phenanthrene-d 10,-d12 and perylene-d 12, said PHAs substitutes being designated as 2-fluorobiphenyl (2-Fluoro-1) and 4, 4' -Terphenyl-d14 (P-Terphenyl-d 14); the PCBs substitute is mixed standard tetrachloro-m-xylene; the concentration of the internal standard substance is 200 mug/L, and the concentrations of the PHAs substitute mixed standard substance and the PCBs substitute are 2000 mug/L and 100 mug/L respectively.

9. The method for simultaneously determining polycyclic aromatic hydrocarbons and polychlorinated biphenyls (PCBs) in soil as claimed in claim 1, wherein: the gas chromatography conditions were: the temperature of a sample inlet is 280 ℃, and the flow is not divided; the sample injection amount is 1.0 mu L, and the column flow is 1.0 mL/min; the ion source temperature is 230 ℃; the temperature rising procedure is as follows: keeping the column temperature at 80 ℃ for 2 min; raising the temperature to 180 ℃ at the speed of 20 ℃/min, and keeping the temperature for 5 min; then the temperature is increased to 290 ℃ at the speed of 10 ℃/min and kept for 10 min.

10. The method for simultaneously determining polycyclic aromatic hydrocarbons and polychlorinated biphenyls (PCBs) in soil as claimed in claim 1, wherein: the mass spectrum conditions are as follows: an electron impact source (EI); ionization energy 0 eV; the interface temperature is 280 ℃; the temperature of a four-level bar is 150 ℃; scanning the range of 45amu to 450 amu; solvent delay time 5 min; the scan mode is a full scan-selective ion mode.

Technical Field

The invention relates to the technical field of soil pollutant analysis and detection, in particular to a method for simultaneously determining polycyclic aromatic hydrocarbon and polychlorinated biphenyl in soil.

Background

Soil is an important resource for human survival and development, and once the soil is polluted, the pollutants in the soil can cause secondary pollution to surface water and underground water. Contaminants in the soil can enter the human body through drinking water or the soil-plant system via the food chain, directly endangering human health. Meanwhile, the degree of importance of the state on soil environmental pollution is greatly improved, related departments such as the department of ecological environment (the department of environmental protection of the original country) and the department of natural resources (the department of native resources of the original country) issue a series of laws and regulations and policies such as the national environmental protection law of the people's republic of China, the law of prevention and treatment of soil pollution, the law of environmental pollution of solid wastes, the law of ten items of soil and the like, and after the national soil pollution general survey stage work is initially completed, the phase of soil pollution treatment is started.

Polycyclic Aromatic Hydrocarbons (PAHs) refer to hydrocarbons in which two or more benzene rings are combined in a linear, angular, or cluster shape. Polycyclic aromatic hydrocarbons mainly come from incomplete combustion of organic pollutants such as petroleum, coal and the like and widely exist in air, soil and water environment. Polycyclic aromatic hydrocarbons have extremely high hydrophobicity and high stability, so that they are easily accumulated in soil. Polychlorinated biphenyls (PCBs) belong to carcinogens, are easily accumulated in adipose tissues, cause diseases of brain, skin and internal organs, and influence nerves, reproduction and immune systems. Polycyclic aromatic hydrocarbons and polychlorinated biphenyls are typical Persistent Organic Pollutants (POPs) with carcinogenic, teratogenic, mutagenic properties in soil. Polycyclic aromatic hydrocarbons have extremely strong hydrophobicity and high stability, so that the polycyclic aromatic hydrocarbons are easy to accumulate in soil, and the soil is a warehouse and a transfer station of the polycyclic aromatic hydrocarbons in natural environment. Once in soil, polycyclic aromatic hydrocarbons will enter the human body through drinking water or the soil-plant system via the food chain, directly endangering human health. So far, a plurality of carcinogenic polycyclic aromatic hydrocarbons such as benzanthracene, benzopyrene and the like have been found, animal experiments show that the polycyclic aromatic hydrocarbons can induce skin cancer, liver cancer, stomach cancer, thyroid cancer, malignant lymphoma, oral cancer and the like, have strong teratogenic, carcinogenic and mutagenic effects, enter human bodies through skin, respiratory tract and digestive tract in the processes of forming, migrating, transforming and degrading, and finally seriously harm human health. Therefore, qualitative and quantitative detection methods for PAHs and PCBs have gained wide attention and research at home and abroad as basic research methods.

The detection method for PAHs and PCBs in soil is mature at home and abroad, and the related standards and analysis methods mostly respectively extract, purify and measure the 2 compounds. At present, the detection standards for PAHs in soil mainly used at home and abroad are HJ805-2016, HJ784-2016, EPA. method 8270E, EPA. method 8310 and the like, and the detection standards for PCBs in soil mainly used at home and abroad are HJ 743-. In actual test work, the existing test method is faced with mass soil samples with short storage time and many test items, and the accuracy and the timeliness of the determination result are greatly reduced. The standards for simultaneously extracting, concentrating, purifying and measuring the multi-component organic pollutants in the soil are not published, only a few reports are made on the research of related analysis and detection methods, and the research mainly aims at the aspects of PHAs and pesticide organochlorine and is only rarely made on the research of simultaneously extracting, purifying and measuring the multi-component organic pollutants such as PAHs, PCBs and the like in the soil.

Therefore, it is a problem to be solved by those skilled in the art to develop a method capable of simultaneously and rapidly determining the PAHs and PCBs multi-component compounds in the soil, and to improve the accuracy and the effectiveness of the detection.

Disclosure of Invention

In view of the above, the present invention aims to provide a method for simultaneously determining polycyclic aromatic hydrocarbons and polychlorinated biphenyls in soil, so as to simultaneously and rapidly determine multi-component compounds of PAHs and PCBs in soil, and improve the accuracy and effectiveness of detection.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a method for simultaneously measuring polycyclic aromatic hydrocarbon and polychlorinated biphenyl in soil comprises

a. Pretreating a soil sample, wherein the pretreatment comprises the steps of removing foreign matters, extracting and purifying by a small column to obtain a sample solution to be detected;

b. quartz sand is selected as a blank sample, and the blank sample is detected by a gas chromatography-mass spectrometer;

c. detecting a sample solution to be detected by using a gas chromatography-mass spectrometer;

d. and deducting the detection result of the blank sample from the detection result of the sample solution to be detected.

Further, step a comprises the following steps:

a1, foreign matter removal: removing foreign matters from the soil sample, and fully and uniformly mixing; adding anhydrous sodium sulfate, and stirring until the sample to be detected is in a quicksand shape; refrigerating at below 4 deg.C for 48 hr;

a2, extracting: refrigerating, and adding 25 μ L of polycyclic aromatic hydrocarbon substitute and tetrachloro-m-xylene; then adding n-hexane and acetone with the same volume for extraction;

a3, extraction: extracting by adopting any one of Soxhlet extraction, pressurized fluid extraction or ultrasonic extraction;

a4, purifying by a small column: pretreating the small column; transferring the liquid obtained in the step a3 to a small column, washing a concentration vessel with n-hexane for three times, and transferring all washing liquid into the small column; adding 5mL of dichloromethane-n-hexane mixed solvent for elution; continuously adding 5mL of dichloromethane-n-hexane mixed solvent, collecting all eluent, and concentrating the eluent; and adding an internal standard substance to obtain a sample solution to be detected.

Further, in the step a2, the liquid level of the n-hexane and the acetone is 2cm higher than the surface of the soil sample.

Further, in step a3, the extraction method is ultrasonic extraction.

Further, the ultrasonic extraction conditions are as follows: the extracting agent is n-hexane and acetone in a volume ratio of 1:1, the ultrasonic frequency is 600W, and the temperature is 25 ℃.

Further, the extraction time of the ultrasonic extraction is 15 min.

Further, the extraction times of the ultrasonic extraction are 4 times.

Further, in step a4, the internal standard substances are naphthalene-d 8, acenaphthylene-d 10, phenanthrene-d 10,-d12 and perylene-d 12, said PHAs substitutes being designated as 2-fluorobiphenyl (2-Fluoro-1) and 4, 4' -Terphenyl-d14 (P-Terphenyl-d 14); the PCBs substitute is mixed standard tetrachloro-m-xylene, the concentration of the internal standard substance is 200 mug/L, and the concentrations of the PHAs substitute mixed standard and the PCBs substitute are 2000 mug/L and 100 mug/L respectively.

Further, the gas chromatography conditions were: the temperature of a sample inlet is 280 ℃, and the flow is not divided; the sample injection amount is 1.0 mu L, and the column flow is 1.0 mL/min; the ion source temperature is 230 ℃; the temperature rising procedure is as follows: keeping the column temperature at 80 ℃ for 2 min; raising the temperature to 180 ℃ at the speed of 20 ℃/min, and keeping the temperature for 5 min; then the temperature is increased to 290 ℃ at the speed of 10 ℃/min and kept for 10 min.

Further, the mass spectrometry conditions are as follows: an electron impact source (EI); ionization energy 0 eV; the interface temperature is 280 ℃; the temperature of a four-level bar is 150 ℃; scanning the range of 45amu to 450 amu; solvent delay time 5 min; the scan mode is a full scan-select ion mode.

Compared with the prior art, the invention has the following advantages:

1. the method firstly removes foreign matters, extracts and purifies the sample to be detected by a small column, then adopts a gas chromatography-mass spectrometer method for detection, can simultaneously analyze 16 PHAs and 18 PCBs in the soil, has high efficiency, sensitivity, low detection limit and short detection period, and improves the accurate determination and the effectiveness of the detection.

2. According to the invention, the polycyclic aromatic hydrocarbon and the polychlorinated biphenyl in the soil are extracted simultaneously by adopting an ultrasonic extraction method, and the mechanical vibration effect, the cavitation effect and the disturbance effect generated by ultrasonic radiation are utilized, so that the adsorption of organic matters on the surfaces of the soil and sediments is destroyed, the frequency and the speed of the molecular motion of the matters are increased, and the penetrating power of a solvent is improved, thereby accelerating the dissolution of the organic matters in an organic phase, effectively improving the extraction efficiency, and further improving the accuracy and the effectiveness of detection.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts. In the drawings:

FIG. 1 is a graph of the PHAs and PCBs SIM patterns chromatograms of example 2.1 of the present invention;

FIG. 2 is a schematic diagram of the recovery rates of 16 PAHs and 18 PCBs in different extraction modes in example 2.2.1 of the present invention;

FIG. 3 is a schematic diagram showing the effect of the number of ultrasonic extractions on the recovery rate in example 2.2.2 of the present invention;

FIG. 4 is a schematic diagram showing the effect of ultrasonic extraction time on recovery rate in example 2.2.3 of the present invention.

Detailed Description

The technical solution in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

In the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be considered as limiting the present invention.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; the connection may be direct or indirect through an intermediate medium, or the connection may be internal to the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to specific situations.

In the invention, an Agilent 7890B-5977B MSD gas chromatography-mass spectrometer (Agilent company in America) is adopted for analysis and detection.

In the invention, 16 polycyclic aromatic hydrocarbons are mixed and marked as naphthalene (Nap), Acenaphthylene (ACL), Acenaphthene (AC), Fluorene (FL), Phenanthrene (PHE), Anthracene (AN), Fluoranthene (FA), Pyrene (PY) and benzo (a) anthracene (BaA),(CHR), benzo (b) fluoranthene (BbFA), benzo (k) fluoranthene (BkFA), benzo (a) pyrene (BaP), dibenzo (a, h) anthracene (DBaha), benzo (g, h, i) perylene (Bghip), indeno (1,2,3-c, d) pyrene (IP).

In the invention, 18 PCBs are labeled as PCB28, PCB52, PCB101, PCB81, PCB77, PCB123, PCB118, PCB114, PCB153, PCB105, PCB138, PCB126, PCB167, PCB156, PCB157, PCB180, PCB169 and PCB189 in a mixing way.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.