Patent Application
20250060344
This application claims the priority of Chinese patent application No. 202311046559.3, entitled “A SEMI-ONLINE ANALYTICAL APPARATUS FOR MEASURING ATMOSPHERIC TRACE NITROGEN-CONTAINING ORGANIC COMPONENTS”, filed at CNIPA on Aug. 18, 2023, which is incorporated by reference herein in its entirety.
This disclosure is related to the field of atmospheric environmental technology, in particular, to a semi-online apparatus for analyzing trace nitrogen-containing organic components in atmospheric fine particulate matter (PM2.5).
Atmospheric fine particulate matter (PM2.5, the aerodynamic particles of diameter less than or equal to 2.5 micrometers) refers to the collective term for various solid and liquid particles present in the atmosphere. These particles maybe uniformly dispersed in the air, forming a relatively stable and large suspended system. PM2.5, a widely studied fine particulate matter due to their properties contaminating air quality, disturbing global climate and impacting public health and ecosystem. Since their inhalable nature, they are also known as inhalable fine particulate matter. With a diameter less than 1/20th the thickness of a human hair, PM2.5 is a residue emitted through fossil fuel combustion processes such as combustion engine vehicle exhaust emission, power generation from conventional fossil fuels, and industrial production. They often contain toxic substances such as heavy metals and aromatic compounds. Although PM2.5 particles are only a trace component of the Earth's atmospheric composition, their small particle sizes and high concentration of toxic and harmful substances, coupled with the long-life time and long-range transport in the atmosphere, PM2.5 particles have significant impacts on human health and the Earth's greenhouse effect. To study PM2.5, researchers typically collect and analyze them over a certain period of time, maybe as long as six months, one year, or even three years. The commonly used collection method is the active sampling, where a pump is used to absorb the PM2.5 onto a medium substance. The commonly used media today include quartz membranes and Teflon™ membranes. However, this method inevitably involves complex pre-treatment procedures, such as cutting the membrane, organic solvent extraction, ultrasonication, concentration, filtration, and chromatographic column purification. If a long-term sampling is required in six months, one year, or even three years, these repetitive operations will consume a significant amount of manpower and resources. Moreover, during this process, there is a high possibility of excessive loss of the target components in the samples, resulting in deviations and instability in the monitoring data. Additionally, after significant improvements in atmospheric pollution control with time, the number of particles in the atmosphere may have significantly decreased, making it difficult to meet the minimum detection limits of instruments for the collected samples. Therefore, there is an urgent need for a particles PM2.5 collection and analysis system that are capable of enrichment capabilities, online operation, low cost, good repeatability, and high automation to address the complex research challenges in the collection and processing of PM2.5.
This disclosure is related to the field of atmospheric environmental technology and specifically is related to a semi-online apparatus for analyzing trace nitrogen-containing organic components in atmospheric fine particulate matter (PM2.5). The apparatus includes a collision-type PM2.5 filter, a resistive heating rod with a temperature sensor, a sealed water tank, a condensation system, a virtual concentrator, a flow controller, a vacuum pump, a particulate matter collection bottle, dimethylacetamide reagent, an ultrasonic bath, a fraction automatic supply/collect integrated pump, a vacuum parallel concentrator, a micro-injection pump, and a liquid chromatography time-of-flight mass spectrometer. This apparatus can replace the traditional filter sampling for collecting PM2.5 thus greatly freeing up manpower, saving resources, and reducing organics loss in PM2.5. The collected sample solution is injected into the liquid chromatography-mass spectrometer for online analysis of organic components. By introducing an enrichment system, the concentration of sample PM2.5 can be increased at least by 10 times, enhancing the sampling sensitivity of the apparatus. This apparatus achieves full automation of PM2.5 sampling and collection. It can be widely applied in air quality monitoring and health risk assessment.
Below are the reference numerals in
It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application.
Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the disclosure. Further, though advantages of the present disclosure are indicated, it should be appreciated that not every embodiment of the disclosure will include every described advantage. Some embodiments may not implement any features described as advantageous herein and in some instances. Accordingly, the foregoing description and drawings are by way of example only.
The present disclosure now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the inventions are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. As used herein, terms such as “top,” “bottom,” “front,” etc. are used for explanatory purposes in the examples provided below to describe the relative position of certain components or portions of components.
The disclosure provides a semi-online analysis apparatus for trace nitrogen-containing organic components having PM2.5. This apparatus contains enrichment function, online capability, low cost, good repeatability, and high degree of automation, fully equipped to solve the complex technical problems of collection and processing data of PM2.5.
The semi-online analysis apparatus for measuring trace nitrogen-containing organic components in PM2.5 provided by this disclosure, as shown in
The collision-type PM2.5 filter 1 is connected to the inlet of the sealed water tank 4 through a matching management connection (e.g., connected by a 16 mm steel pipe and an 18 mm conductive silicone tube).
The sealed water tank 4 is made of stainless steel, which facilitates the full heat conduction of the water tank. It is equipped with a transparent window 2 made of high-strength glass on the right side of the front, which is used to observe the liquid level of the ultrapure water added to the tank.
The resistance heating rod with temperature sensor 3 is set inside the sealed water tank 4, 25-35 cm away from the bottom. The temperature sensor carried by the resistance heating rod is connected to the data line, and the temperature sensor is at least 30 cm away from the heating rod, inserted parallel to the heating rod from a position 3-4 cm above the bottom of the water tank, with a depth of 5-10 cm. The resistance heating rod is used to heat the ultrapure water in the sealed water tank 4, and the temperature sensor is used to measure the temperature of the ultrapure water in the sealed water tank 4.
The internal condensation tube 7 of the condenser is connected to the outlet of the sealed water tank on the left side through a customized flange.
The external condensation coil 6 of the condenser is tightly wound around the external surface of the internal condensation tube 7 of the condenser. It is made of flexible copper material. The condenser 5 is connected to both ends of the external condensation coil 6. The ethanol coolant generated by the condenser 5 passes through the external condensation coil 6, producing a cooling effect. A layer of pure cotton insulation layer 8 is wrapped around the external condensation coil 6 for heat preservation.
The low end of virtual concentrator 9 is coaxially connected to the upper end of the internal condensation tube 7 of the condenser through a customized flange. The virtual concentrator 9 divides the airflow into two paths: exhausted gas path (upper right outlet of the virtual concentrator 9) and concentrated gas path (upper left outlet of the virtual concentrator 9). The concentrated gas path is connected to the inlet of the particulate matter collection bottle 12 through a fixed pipeline. The exhausted gas path is connected to the high-flow volume flow controller 10 through a pipeline, and then to the high-flow vacuum pump 11.
The ultrasonic bath 16 is filled with ultrapure water to a height of 10-15 cm.
The particulate matter collection bottle 12 is suspended in the cavity of the ultrasonic bath 16 (i.e., with a small distance (such as 2-3 cm) from the bottom of the ultrasonic bath 16). The upper outlet of the particulate matter collection bottle 12 is connected to the low-flow volume flow controller 13 and the low-flow vacuum pump 14 in sequence. The low-flow vacuum pump 14 is used to extract the concentrated airflow in the concentrated gas path into the particulate matter collection bottle 12, and the low-flow volume flow controller 13 is used to control the flow rate of the concentrated gas extracted into the particulate matter collection bottle 12 by the low-flow vacuum pump 14.
The middle and bottom positions of the particulate matter collection bottle 12 are respectively connected to the supplying and collecting pipelines of the fraction automatic supply/collect integrated pump 17. The fraction automatic supply/collect integrated pump 17 supplies the dimethylacetamide solvent 15 into the particulate matter collection bottle 12 through a pipeline, and collects the atmospheric sample dissolved in the dimethylacetamide solvent 15 in the particulate matter collection bottle 12 through another pipeline.
The fraction automatic supply/collect integrated pump 17 is connected to the vacuum parallel concentrator 18 and the micro-injection pump 19 in sequence through pipelines. The vacuum parallel concentrator 18 concentrates the sample solution collected and transferred by the fraction automatic supply/collect integrated pump 17 to a specified volume, and then transfers the concentrated sample solution of the set volume to the micro-injection needle on the micro-injection pump 19. The remaining solution is diverted to the exhausted liquid bucket.
The micro-injection needle on the micro-injection pump 19 is connected in series with the liquid phase inlet of the liquid chromatography-time-of-flight mass spectrometer 20 through a Teflon™ pipeline. During injection, the micro-injection pump provides a constant injection pressure to the micro-injection needle to ensure a constant injection volume. After the injection is completed, the liquid chromatography-time-of-flight mass spectrometer 20 is activated to analyze the organic components in the collected sample solution.
The present disclosure apparatus is used for the concentration, collection, and semi-online analysis of atmospheric particulate matter. The collision-type PM2.5 filter 1 is used to filter out atmospheric particles with an aerodynamic diameter less than or equal to 2.5 micrometers, and the filtered particles are drawn into the apparatus by the suction force provided by the high-flow vacuum pump 11 and the low-flow vacuum pump 14. The specific process is as follows:
The apparatus operates in a cyclic manner according to the set time, enabling semi-online analysis of trace nitrogen-containing organic components in PM2.5.
The present disclosure describes a semi-online apparatus for analyzing trace nitrogen-containing organic components in PM2.5. This apparatus can replace traditional filter sampling methods for collecting PM2.5, eliminating the need for filter cutting, organic solvent extraction, and other pre-treatment processes. This greatly reduces labor and material costs, while also minimizing losses during sample handling and transfer. Additionally, the introduction of an enrichment system allows for a tenfold increase in the concentration of atmospheric particulate matter, significantly enhancing the sampling capability of the apparatus. Furthermore, this apparatus achieves fully automated sampling and collection of atmospheric particulate matter, requiring only the setting of sampling time and period. By using a specific organic solvent that can be directly injected into the chromatography without damaging the chromatographic column, this apparatus can be used in conjunction with gas chromatography and liquid chromatography. The collected sample solution can be quantitatively concentrated online using a vacuum parallel concentrator, enabling online quantitative collection of atmospheric PM2.5 samples. Finally, the collected sample solution is injected into the liquid chromatography-mass spectrometry system using a micro-injection pump for online analysis of the organic components in the collected sample solution. This apparatus has wide applications in environmental monitoring and health risk assessment.
The technical features and advantages of this disclosure are as follows:
Following are some specific implementation methods such as the implementation Example 1. The present disclosure is further described through the implementation examples and accompanying
First, ultrapure water is injected into the water tank 4 to a ⅗ of the total height. The temperature control is set to 35±1 degrees Celsius, and the ultrapure water is heated using a resistive heating rod 3 equipped with a temperature sensor. At the same time, an 80% ethanol solution (aqueous solution) is injected into the condenser 8, and its temperature is set to −10±1 degrees Celsius. The condensate external circulation is then opened. Next, a collision-type PM2.5 filter is placed in the actual atmospheric environment, and the high-flow vacuum pump 11 and low-flow vacuum pump 14 are turned on. The high-flow vacuum pump flow is controlled to 65 liters per minute using the high-flow volume flow controller 10, and the low-flow vacuum pump flow is controlled to 6 liters per minute using the low-flow volume flow controller. Subsequently, 10 milliliters of dimethylacetamide reagent are injected into the particulate matter collection bottle using the fractional automatic supply/collect integrated pump 17, and the sample solution collected by the dimethylacetamide reagent is collected in the vacuum parallel concentrator 18. Then, new dimethylacetamide reagent (10 milliliters) is injected. The 18 vacuum parallel concentrator is opened, and the quantitative concentration volume is set to 1 milliliter with an operation period of 1 hour. Finally, the concentrated collected sample solution is injected into the ultra-high pressure liquid chromatography-time-of-flight mass spectrometer 20 (7 microliters) using a micro-injection pump for online detection and analysis of organic components in the collected sample solution. This apparatus achieves semi-online analysis of trace nitrogen-containing organic components in PM2.5, mainly based on PM2.5 enrichment sampling and sample solvent quantitative concentration technology, greatly improving the concentration of collected particulate matter. In addition, using organic solvents as the medium for sampling PM2.5 eliminates the complicated pre-treatment processes. For example, traditional filter sampling includes steps of membrane cutting, organic solvent extraction, ultrasound, and concentration. As shown in Table 1, the concentrations of 4-nitrophenol, 4-nitrophenol, and 5-nitrosalicylic acid in the samples after enrichment are increased by nearly ten times, optimizing the detection limit of trace organic compounds in particulate matter. As shown in Table 2, the volume after concentration is consistent with the set concentration volume (1 milliliter), indicating that the apparatus has excellent quantitative detection capability. The concentrations of trace nitrogen-containing organic components (4-nitrophenol, 4-nitrocatechol, and 5-nitrosalicylic acid; unit: nanograms per cubic meter) in PM2.5 before and after enrichment by this sampling apparatus is compared in Table 1. The volume before and after vacuum concentration by 18 vacuum parallel concentrator is compared in Table 2.
The disclosure provides a semi-online analysis apparatus for trace nitrogen-containing organic components in PM2.5, which has enrichment function, online capability, low cost, good repeatability, and high degree of automation, in order to solve the technical problems of complex collection and processing processes of PM2.5.
Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202311046559.3 | Aug 2023 | CN | national |
| 202322233095.9 | Aug 2023 | CN | national |
