A method for detecting and analyzing silver ion content in precipitation after weather modification operation

Abstract

The present application relates to a kind of artificial weather modification operation after the detection and analysis method of silver ion content in precipitation, detection method includes collecting artificial weather modification operation after precipitation as to be measured sample, preparation Ag's series standard solution and internal standard solution, to be measured sample digestion, ICP-MS working parameter setting, on-machine detection, according to the ICP-MS detection value obtained by detecting series standard solution and establish the regression equation of silver ion, the ICP-MS detection value of to be measured sample is substituted into regression equation, and the silver ion concentration of to be measured sample can be obtained.The silver ion content detection provided by the present application uses inductively coupled plasma mass spectrometry method, this method has the advantages of fast detection speed, low detection limit, high detection precision, silver ion content analysis method includes silver ion content distribution characteristic analysis and the influence analysis to ecological environment.The present application provides basic support for the green and sustainable development of artificial weather modification work.

Description

TECHNICAL FIELD

[0001] The application relates to a method for detecting and analyzing the content of silver ions in precipitation after weather modification operation, and belongs to the technical field of detection. BACKGROUND

[0002] Weather modification catalysts include refrigerants, hygroscopic catalysts and ice-forming agents. The refrigerants mainly include dry ice (solid carbon dioxide), liquid carbon dioxide and liquid nitrogen and other quick-acting refrigerants. After the catalysts are scattered, they soon become carbon dioxide gas and nitrogen gas, which are components of air and do not pollute the ecological environment. The hygroscopic catalysts mainly include sodium chloride, urea and ammonium nitrate and other substances, which have strong hygroscopicity and corrosion and can cause soil salinization and damage to crops, but the current amount of hygroscopic catalysts is very small, and the influence on the environment can be ignored. As an ice-forming agent, silver iodide (AgI) is the best artificial ice nucleus substance discovered so far and is the most widely used catalyst in current weather modification field tests and business operations. Iodine (I) in AgI is a food nutrient required by humans, but silver ions (Ag + ) are heavy metals and have certain toxicity. With the continuous expansion of the current weather modification operation scale, the influence of AgI catalyst on the ecological environment and human body has attracted widespread attention. Mastering the content of silver ions (Ag + ) in precipitation before and after weather modification operation and analyzing the possible influence of AgI catalyst on the ecological environment of the Qinghai-Tibet Plateau are the premise and basis for the sustainable development of weather modification work, and have important significance for better playing the role of the first line of defense of meteorological disaster prevention and reduction and empowering the high-quality development of weather modification work.

[0003] Internationally, research on the influence of weather modification scattering AgI on the environment has been conducted since the 1960s. Researchers analyze the possible influence on the environment by detecting the content of silver ions (Ag + ) in the rain and snow after catalysis, the content of AgI in soil, lakes and rivers, and combining theoretical calculation. Domestic detection of the content of silver ions (Ag + ) in catalytic precipitation and detection of the content of silver ions (Ag + ) in reservoirs began in the 1970s to analyze the possible influence of AgI catalysis on the environment. For example, Chen Lishu et al. used atomic absorption and flame emission spectrophotometry to determine the content of silver ions (Ag + ) in rainwater in Hunan Province (Chen Lishu, Wang Daofan. Statistical analysis of silver content in rainwater in weather modification test area of Hunan Province from 1978 to 1980 [J]. Acta Meteorologica Sinica, 1983 (04): 117-123.) Zeng Guangping et al. used graphite furnace atomic absorption method to determine the content of silver ions (Ag +) content (Qiangping Ceng. Artificial rainfall test in Gutian reservoir area of Fujian province, China. Water silver ion (Ag + ) distribution research[J]. Tropical meteorology, 1989(1):63-71). Zhao Xifang et al. used atomic absorption spectrometry to determine the influence of artificial precipitation on the silver ion (Ag + ) content in the water quality of Miyun reservoir (Zhao Xifang, Zhang Qiang, Qin Changxue, Zhao Shuyan. Research on the influence of artificial precipitation on the silver ion (Ag+) content in the water quality of Miyun reservoir[J]. Meteorology, 2006, 32(5):46-51; Zhao Xifang, Zhang Qiang, Zhao Shuyan. Research on the influence of artificial precipitation on the silver ion (Ag+) content in the water quality of Miyun reservoir[J]. Meteorological science and technology, 2008, 36(4):468-473).

[0004] The current “groundwater quality standard” (GB T / 14848-2017) and “drinking water health standard” (GB5749-2022) have clear requirements for the silver ion (Ag + ) content in water, that is, the silver ion (Ag + ) content in water does not exceed 50 μg / L, which is consistent with the drinking water standard specified by the World Health Organization. The above research is earlier and uses graphite furnace atomic absorption method to determine the silver ion (Ag + ) content in precipitation, which has low work efficiency and high detection limit, and it is difficult to meet the domestic and international silver ion (Ag + ) content requirements.

[0005] Inductively coupled plasma mass spectrometry (ICP-MS) is an inorganic trace and ultra-trace element analysis and testing technology developed in the 1980s of the 20th century, which has the advantages of fast analysis speed, wide dynamic linear range, high sensitivity, and can perform multi-element simultaneous rapid determination. However, due to technical limitations, there is no ICP-MS detection method for silver ion (Ag + ) content in artificial precipitation, and no unified analysis method for silver ion (Ag + ) content in precipitation after artificial precipitation operation has been reported. SUMMARY

[0006] (1) Technical problems to be solved

[0007] In order to solve the problem of low work efficiency and high detection limit of the existing technology for detecting silver, the present application provides an ICP-MS detection method and analysis method for silver ion (Ag + ) content in precipitation after weather modification operation.

[0008] (2) Technical scheme

[0009] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0010] Silver ions (Ag) in precipitation after weather modification operations + The ICP-MS method for detecting the content of ) includes the following steps:

[0011] S1. Collect precipitation after weather modification operations as the sample to be tested;

[0012] S2. Prepare Ag stock solution with a concentration of 500–1000 mg / L; prepare Ag stock solution with a concentration of 10 mg / L. 6 Li, 45 Sc、 72 Ge 89 Y、 115 In、 159 Tb, 209 Bi mixed internal standard stock solution;

[0013] S3. Digest the sample to be tested, and then process it into a solution to be tested.

[0014] S4. Prepare a series of standard solutions; starting with a 500-1000 mg / L Ag standard stock solution, gradually dilute to prepare a series of standard solutions with known gradient concentrations;

[0015] S5. Dilute the mixed internal standard stock solution to prepare an injection internal standard solution with a concentration of 1 μg / mL for each metal element.

[0016] S6. Under the set ICP-MS operating parameters, the injection internal standard solution and a series of standard solutions with gradient concentrations are mixed and injected online for detection to obtain the ICP-MS detection values ​​of the series of standard solutions; the injection internal standard solution and the test solution are mixed and injected online for detection to obtain the ICP-MS detection value of the test sample.

[0017] S7. Based on the ICP-MS detection values ​​obtained from a series of standard solutions and the establishment of a regression equation for silver ions, the concentration of silver ions in the sample to be tested can be obtained by substituting the ICP-MS detection value of the sample into the regression equation.

[0018] As described above, preferably, in step S1, during the process of collecting precipitation after artificial weather modification operations, the diffusion simulation of silver iodide catalyst after aircraft-based artificial rain or snow, ground-based artificial rain or snow, or ground-based artificial hail suppression operations in the key study area is first carried out according to the high-resolution artificial weather modification model system HR-WMM. Based on the diffusion path and diffusion area of ​​the silver iodide catalyst, ground precipitation sampling points are set in combination with terrain features. Rainwater samples are collected from the beginning to the end of precipitation at the sampling points as samples to be tested.

[0019] Furthermore, the sampling points are set up according to the following principles: sampling points are located within the diffusion zone of the silver iodide catalyst; sampling points are arranged in descending order of catalyst diffusion concentration, and the spacing is made as equal or similar as possible according to the terrain features; sampling points are increased in areas with high catalyst concentration and reduced accordingly in areas with low concentration; sampling points should avoid uninhabited areas, glacier areas and dangerous areas to ensure the safety of sampling personnel; and polyethylene containers and tools are used for the collection and transportation of precipitation.

[0020] Preferably, in step S3, the digestion of the sample to be tested is carried out in a microwave digester with the parameters set as follows: 800-1000W pressure, ramp time of 3-8 minutes, and holding time of 3-8 minutes; 1400-1500W pressure, ramp time of 3-8 minutes, and holding time of 15-25 minutes; and the cooling process is carried out at 0W pressure with a holding time of 10-20 minutes.

[0021] In the method described above, preferably, the test solution, the series of standard solutions, and the injection internal standard solution are all obtained by diluting with nitric acid with a mass concentration of 3-10%.

[0022] In the method described above, preferably, in step S4, the concentrations of Ag in the series of standard solutions are 0, 2, 5, 10, 30, 60, 80, and 100 mg / L, respectively.

[0023] As described above, preferably, in step S6, the ICP-MS on-machine detection includes first adding... 6 Li, 45 Sc、 72 Ge 89 Y、 115 In、 159 Tb, 209 A mixed internal standard solution of Bi was prepared. Then, under the set ICP-MS working conditions, the internal standard solution, a series of standard solutions and the test solution were injected. The ICP-MS detection values ​​were obtained and the silver ion content of the test solution was calculated.

[0024] As described above, preferably, the ICP-MS operating parameters are: RF power of 1500W, RF voltage of 1.67V, atomization chamber temperature of 2℃, sampling depth of 8.1mm, carrier gas flow rate of 0.85L / min, compensation gas flow rate of 0.21L / min, and peristaltic pump rate of 0.1rps.

[0025] A method for analyzing the silver ion content in precipitation after weather modification operations, comprising the following steps:

[0026] 1) The detection data of the sample to be detected obtained by the above detection method is divided into three categories: sample data after aircraft artificial precipitation / snow operation, sample data after ground artificial precipitation / snow operation and sample data after ground artificial hail prevention operation, and the distribution characteristics of silver ion content in precipitation under different operation modes are analyzed in combination with GIS maps;

[0027] 2) The influence of silver ion content on the ecological environment is analyzed.

[0028] In a preferred embodiment, in step 2), when the silver ion content in the detection result is all lower than 50 μg / L, it indicates that the artificial weather influence operation has no influence on the ecological environment; when the silver ion content in the detection result is all higher than 50 μg / L, the artificial weather influence operation should be suspended first, and whether the detection result is caused by the artificial weather influence operation is analyzed.

[0029] (III) Beneficial effects

[0030] The beneficial effects of the present application are:

[0031] The present application provides an ICP-MS detection method for silver ion (Ag + ) content in precipitation after artificial weather influence operation, which first uses high-resolution artificial weather influence mode system to carry out diffusion simulation before sample collection is carried out, so as to determine the sampling point, greatly reducing the workload under the premise of ensuring scientificity, and secondly applies the ICP-MS method to the field of artificial weather influence for the first time, which has the characteristics of fast detection speed, low detection limit, high detection precision and detection accuracy.

[0032] The present application also provides an ICP-MS detection method for silver ion (Ag + ) content in precipitation after artificial weather influence operation, which includes silver ion (Ag + ) content distribution characteristic analysis and influence on the ecological environment analysis, and provides a basic support for the green and sustainable development of artificial weather influence work. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a distribution diagram of the silver iodide catalyst diffusion path and diffusion area of the high-resolution artificial weather influence mode simulation. DETAILED DESCRIPTION

[0034] In order to better explain the present application, the present application is described in detail below through specific embodiments. If not specifically indicated, the technical means used below is the conventional means familiar to those skilled in the art.

[0035] The precipitation in the application is the ground precipitation collected after the artificial weather modification operation. Before the ground precipitation collection, based on the high resolution artificial weather modification model system (HR-WMM), the silver iodide catalyst diffusion simulation after the airplane artificial rain (snow) increasing, ground artificial rain (snow) increasing or ground artificial hail prevention operation in the key research area is carried out, according to the silver iodide catalyst diffusion path and diffusion area, the ground precipitation sampling points are scientifically set combining with the terrain characteristics, so that the sampling can ensure the scientificity and representativeness of the precipitation sampling and reduce the workload of the precipitation sampling.

[0036] All the sample collection uses the polyethylene material container and tool to avoid the heavy metal pollution. After the sampling is completed, the sample should be immediately sent for detection.

[0037] Example 1

[0038] The ICP-MS detection method of the silver ion (Ag + ) content in the precipitation after the artificial weather modification operation, comprising the following steps:

[0039] 1. The precipitation collection after the artificial weather modification operation;

[0040] 2. Instruments and reagents;

[0041] 3. Sample digestion;

[0042] 4. Preparation of standard solution;

[0043] 5. Preparation of internal standard solution;

[0044] 6. ICP-MS on-machine detection.

[0045] The specific steps are:

[0046] 1. The precipitation collection after the artificial weather modification operation

[0047] The weather modification operation is carried out, including airplane artificial precipitation (snow) operation, ground rocket / stove artificial precipitation (snow) operation, ground antihail gun artificial hail prevention operation, then, the diffusion simulation method is used to collect rainwater samples from the beginning to the end of the precipitation in the operation area and the influence area after the operation, and the precipitation sampling amount is 100-500ml. In order to avoid heavy metal pollution, polyethylene containers and tools are used for precipitation collection and transportation, and the sampling is sent to the detection center in time after the sampling is completed. The diffusion simulation method used is based on the high-resolution weather modification model system (HR-WMM). The system is a weather modification model system considering local terrain, weather system and other factors. It applies SJY-FDDA four-dimensional data assimilation technology, is based on WRF-ARW dynamic architecture, embeds WRF-LES large eddy model, has the capabilities of cloud physical quantitative prediction, catalyst effect microphysical response, catalyst diffusion, transportation and nucleation, and has good weather system simulation capability and weather modification catalyst simulation capability. It is a specific diffusion simulation method. Specifically, the high-resolution weather modification model system (HR-WMM) uses GFS (Global Forecast System, developed and operated by the U.S. National Environmental Prediction Center) or EC (European Centre for Medium-Range Weather Forecasts, abbreviated as EC) prediction data as the initial field, sets the output spatial resolution not less than 3km, the grid distance is 15km, 3km and 1km respectively, uses 5th order horizontal advection scheme, 3rd order vertical advection scheme, 2D-Smagorinsky horizontal diffusion scheme, Smoothing-desmoothing space smoothing scheme, Noah-MP ground layer scheme, YSU atmospheric boundary layer scheme, RRTM atmospheric longwave radiation scheme, Thompson cloud microphysical parameterization scheme, 3rd order Runge-Kutta integral scheme and Kain-Fritch cumulus parameterization scheme. The prediction time of meteorological field and cloud field data is 48h, including temperature, humidity, air pressure, wind speed, wind direction, vertical air flow velocity, water vapor, cloud water, ice crystal, rainwater, snowball and graupel particle water content, etc. At the same time, the model system covers the condensation nucleation and contact freezing nucleation process of artificial weather modification catalyst (AgI particle), the advection transportation and diffusion process of AgI particle number concentration, the removal process of AgI particle through condensation nucleation, contact freezing nucleation and other dry and wet deposition, etc. Mechanism, can accurately simulate the diffusion path and main influence area of artificial catalyst under the condition of complex plateau terrain.

[0048] Based on the diffusion path and diffusion zone of silver iodide catalyst obtained from the high-resolution weather modification model simulation system, surface precipitation sampling points were set up in conjunction with topographic features. The sampling point layout followed these principles: 1. Most sampling points should be placed within the catalyst diffusion zone, with a small number of sampling points placed on the periphery of the diffusion zone to verify the accuracy of the model simulation. 2. Sampling points were arranged in descending order of catalyst diffusion concentration, with spacing as equal or similar as possible based on topographic features. 3. The number of sampling points should be appropriately increased in areas with high catalyst concentrations and reduced accordingly in areas with low concentrations; for example... Figure 1 The image shows the diffusion path and diffusion zone distribution of silver iodide catalyst obtained after a ground-based smoke generator operation simulated by a high-resolution weather modification model. The red areas represent high-value zones, and the yellow areas represent low-value zones. However, each simulation will vary depending on the operation method (aircraft operation, rocket operation, smoke generator operation) and the amount of catalyst used. More sampling points can be set in the high-value zones as needed, and fewer sampling points can be set in the low-value zones. 4. Based on terrain features, sampling points should avoid uninhabited areas, glaciers, and other dangerous areas to ensure the safety of sampling personnel.

[0049] Following weather modification operations, precipitation sampling is conducted in the field, requiring significant manpower and resources for personnel, equipment, and sample transportation. Furthermore, silver ions in precipitation are trace substances, making detection expensive. Model simulations, on the other hand, can scientifically and rationally deploy sampling points while ensuring their representativeness. This approach guarantees the representativeness and scientific validity of the sampling points, preventing the omission of important areas, and avoiding personnel and financial losses caused by indiscriminate sampling point deployment.

[0050] Without high-precision model simulations, ensuring accurate sampling requires significant manpower and resources for precipitation sampling, resulting in financial losses and jeopardizing personnel safety. Furthermore, large-scale sampling necessitates support from multiple departments and funding sources, making it difficult for most organizations to undertake. Even if sampling is conducted, much of the data may lack representativeness or exhibit high repetition, leading to a low return on investment and hindering the project's sustainability.

[0051] 2. Instruments and reagents

[0052] Instruments: Inductively coupled plasma mass spectrometer (ICP-MS) (Agilent Technologies, USA), microwave digester, ultrapure water treatment system (Millipore, USA) or purchased ultrapure water, ensuring that its resistivity is greater than 18 MΩ·cm, total organic carbon (TOC) is less than 50 μg / L, and total bacterial count is less than 1 CFU / mL.

[0053] Reagents: 1000 mg / L Ag standard solution; 10 mg / L each of the following... 6 Li,45 Sc, 72 Ge, 89 Y, 115 In, 159 Tb, 209 Bi mixed internal standard solution (available from Agilent, USA).

[0054] 3. Sample digestion

[0055] 1 ml of the water sample to be tested was taken and placed in a polytetrafluoroethylene (PTFE) digestion tank, 5 ml of 5% nitric acid was added, sealed with a cover, and subjected to microwave digestion. The microwave digestion parameters are shown in Table 1, i.e. under 800 W pressure, the ramping time was 5 minutes, and the holding time was 5 minutes; under 1400 W pressure, the ramping time was 5 minutes, and the holding time was 20 minutes; the cooling process was under 0 W pressure, and the holding time was 15 minutes.

[0056] After digestion was completed, the digestion tank was placed on a constant temperature heating digestion instrument, and slowly heated to red-brown vapor at 200 degrees Celsius until it was completely volatilized, and then concentrated to about 0.5 ml, and then cooled. The sample was transferred to a clean test tube, diluted to 10 ml with 5% dilute nitric acid, and shaken well.

[0057] The blank control sample was prepared as above.

[0058] Table 1 Microwave digestion parameters

[0059] Pressure (Watt) Climbing time (min) Retention time (min) 800 5 5 1400 5 20 0 0 15

[0060] 4. Preparation of standard solution

[0061] An appropriate amount of Ag standard solution with a concentration of 1000 mg / L was taken and diluted with 5% nitric acid to a concentration of 0, 2, 5, 10, 30, 60, 80, and 100 mg / L.

[0062] 5. Preparation of internal standard solution

[0063] An appropriate amount of mixed internal standard solution containing 6 Li, 45 Sc, 72 Ge, 89 Y, 115 In, 159 Tb, 209 Bi with a concentration of 10 mg / L was taken and diluted with 5% nitric acid to an internal standard solution of 1 μg / ml.

[0064] 6. ICP-MS on-machine detection

[0065] On-line addition of 6 Li, 45 Sc, 72 Ge,89 Y、 115 In、 159 Tb、 209 Bi mixed internal standard solution, and the content of silver element is detected by inductively coupled plasma mass spectrometer (ICP-MS), and the working conditions of ICP-MS are shown in Table 2.

[0066] Table 2 Working parameters of inductively coupled plasma mass spectrometer (ICP-MS)

[0067] ICP-MS parameters Value Radio frequency power (RF power) 1500W Radio frequency voltage (RF matching) 1.67V Spray chamber temperature (S / C temperature) 2℃ Sample Depth 8.1 mm Carrier gas flow rate 0.85 L / min Makeup gas flow rate 0.21 L / min Nebulizer Pump flow rate 0.1 rps

[0068] 7. Linear relationship and detection limit

[0069] Before each sample is determined, the system is flushed with nitric acid solution until the signal reaches the minimum, and after the analysis signal is stable, the standard solution is respectively sampled and analyzed to obtain the linear equation and correlation coefficient of the silver element. The blank control solution is tested, 11 times of continuous sampling, and the detection limit is calculated by dividing the 3 times standard deviation of the determination value of the blank control solution by the corresponding element standard curve slope.

[0070] The regression equation of the silver element is: y=0.013x+6.82x10 -4

[0071] Wherein, y is the signal intensity, and x is the concentration of the element to be measured (silver ion, mg / L).

[0072] The correlation coefficient is: 0.9998;

[0073] The detection limit is: 0.001 ug / L;

[0074] The relative deviation is: 3%;

[0075] The precision is: 0.210.

[0076] For the silver ion concentration of the sample to be measured, the ICP-MS detection value of the sample to be measured is substituted into the regression equation to obtain the silver ion concentration of the sample to be measured.

[0077] The above results show that the silver ion (Ag+) content detection method for precipitation after weather modification operation based on inductively coupled plasma mass spectrometer (ICP-MS) established by the application has the characteristics of simple pretreatment, rapid and accurate detection result, low detection limit and high detection precision.

[0078] The application also provides an analysis method for the silver ion (Ag + ) content in precipitation after weather modification operation, comprising the following steps:

[0079] 1) Analysis of the distribution characteristics of silver ion (Ag+) content

[0080] The sample detection data is divided into three categories: samples after aircraft artificial precipitation (snow) operation, samples after ground artificial precipitation (snow) operation, and samples after ground artificial hail prevention operation. Combined with geographic information system (GIS) maps, the distribution characteristics of silver ion content in precipitation under different operation modes are analyzed respectively.

[0081] 2) Analysis of the impact of silver ion (Ag + ) content on the ecological environment

[0082] According to the current "Groundwater Quality Standard" (GB T / 14848-2017), "Drinking Water Health Standard" (GB5749-2022) and the drinking water standard stipulated by the World Health Organization, the silver content in water should not exceed 50 μg / L. The detection results are compared with the above standards to analyze the impact of silver ion (Ag + ) content on the ecological environment.

[0083] If the silver ion (Ag + ) content in the detection results is less than 50 μg / L, it indicates that the artificial weather modification operation has no impact on the ecological environment.

[0084] If it is higher than 50 μg / L, it indicates that the silver ion content in the precipitation in this area exceeds the standard. First, the artificial weather modification operation should be suspended, and then in-depth analysis should be carried out to determine whether it is caused by artificial weather modification operation. Based on the current research, the silver ion concentration in precipitation after artificial weather modification operation is less than the standard value by 2-3 orders of magnitude, which will not exceed the standard.

[0085] Example 2

[0086] In 2023-2024, according to the method described in Example 1 of the present invention, aircraft artificial precipitation (snow), ground artificial precipitation (snow) and ground artificial hail prevention operation after precipitation sampling and silver ion (Ag + ) content detection and analysis were carried out. Some of the test results are shown in Table 3.

[0087] Table 3 Partial test results

[0088]

[0089] Among them, ND means not detected.

[0090] The results show that the silver ion (Ag +The silver content in the water is not more than 50 mu g / L, which does not exceed the current groundwater quality standard (GB T / 14848-2017), the drinking water health standard (GB 5749-2022) and the drinking water standard of the World Health Organization.

[0091] Example 3 Precision experiment

[0092] The precipitation sample collected at the same time under the same weather process at the same collection point is divided into 10 parts, sample pretreatment is carried out according to the method of example 1 of the application, and analysis is carried out according to the same microwave digestion and ICP-MS working conditions, the average concentration of silver ions and the relative standard deviation (RSD) are calculated. The results show that the average concentration of silver ions is 0.85 mu g / L, and the relative standard deviation (RSD) is 0.3%.

[0093] The method of the application introduces the ICP-MS method into the field of weather modification, and carries out the detection of silver ions in precipitation after weather modification operation under different operation means, so as to lay a foundation for the research on the effect of weather modification catalytic operation and the influence on ecological environment, and support the sustainable development of weather modification science.

[0094] The above is only a preferred embodiment of the application, and is not intended to limit the application in other forms. Any person skilled in the art can modify or modify the above disclosed technical content to equivalent embodiments. However, any simple modification, equivalent change and modification made on the basis of the technical essence of the application to the above embodiments still belongs to the protection scope of the technical scheme of the application.

Claims

1. A method for detecting the content of silver ions in precipitation after weather modification operations by ICP-MS, characterized in that, It comprises the following steps: S1, collecting precipitation after weather modification operation as a sample to be tested; S2, preparing Ag standard mother liquor with a concentration of 500-1000 mg / L; Prepare the mixed internal standard mother liquor of Li, Sc, Ge, Y, In, Tb and Bi with the concentration of 10 mg / L respectively 6 Li, 45 Sc, 72 Ge, 89 Y, 115 In, 159 Tb, 209 Bi S3, digesting the sample to be tested, and processing the digested sample into a solution to be tested; S4, preparing a series of standard solutions; starting from the Ag standard mother liquor with a concentration of 500-1000 mg / L, a series of standard solutions with known gradient concentrations are prepared by gradual dilution; S5, diluting the mixed internal standard mother liquor into an injection internal standard solution in which the concentration of each metal element is 1 μg / mL; S6, under the set ICP-MS working parameters, the injection internal standard solution and the series of standard solutions with gradient concentrations are mixed and injected on-line for detection to obtain the ICP-MS detection values of the series of standard solutions; The injection internal standard solution and the solution to be tested are mixed and injected on-line for detection to obtain the ICP-MS detection value of the sample to be tested; S7, according to the ICP-MS detection values of the series of standard solutions and the establishment of the regression equation of silver ions, the ICP-MS detection value of the sample to be tested is substituted into the regression equation to obtain the silver ion concentration of the sample to be tested; In step S1, during the collection of precipitation after weather modification operation, first, according to the high-resolution weather modification model system, the diffusion simulation of silver iodide catalyst after aircraft artificial rain or snow, ground artificial rain or snow, or ground artificial hail prevention operation in the key research area is carried out, and according to the diffusion path and diffusion area of the silver iodide catalyst, the ground precipitation sampling points are set in combination with the terrain characteristics; the rainwater sample from the beginning to the end of precipitation at the sampling point is collected as the sample to be tested; wherein, the high-resolution weather modification model system uses GFS or EC prediction data as the initial field, sets the output spatial resolution to be not less than 3 km, the grid distance is 1.5 km, 3 km and 1 km respectively, uses 5-order horizontal advection scheme, 3-order vertical advection scheme, 2D-Smagorinsky horizontal diffusion scheme, Smoothing-desmoothing spatial smoothing scheme, Noah-MP ground layer scheme, YSU atmospheric boundary layer scheme, RRTM atmospheric longwave radiation scheme, Thompson cloud microphysics parameterization scheme, 3-order Runge-Kutta integration scheme and Kain-Fritch cumulus parameterization scheme; The setting of the sampling points follows: the sampling points are set in the diffusion area of the silver iodide catalyst; the sampling points are arranged in order from high to low along the concentration of the catalyst, and the interval is as equal or close as possible according to the terrain characteristics; the sampling points are increased in the high-value area of the silver iodide catalyst concentration and decreased in the low-value area; the sampling points should avoid uninhabited areas, glacier areas and dangerous areas to ensure the safety of the sampling personnel.

2. The detection method of claim 1, wherein the collection and transportation of the precipitation are carried out using polyethylene containers and tools. ​ 3. The detection method as described in claim 1, characterized in that, In step S3, the digestion of the sample to be tested is performed in a microwave digestion instrument, and the parameters are set as follows: 800-1000 W pressure, ramp time 3-8 min, holding time 3-8 min; 1400-1500 W pressure, ramp time 3-8 min, holding time 15-25 min; cooling process at 0 W pressure, holding time 10-20 min.

4. The detection method as described in claim 1, characterized in that, The test solution, the series of standard solutions, and the sample internal standard solution are obtained by diluting 3-10% nitric acid.

5. The detection method as described in claim 1, characterized in that, In step S4, the concentrations of Ag in the series of standard solutions are 0, 2, 5, 10, 30, 60, 80, and 100 mg / L, respectively.

6. The method of claim 1, wherein, In step S6, the on-machine detection of the ICP-MS includes, first adding 6 Li, 45 Sc, 72 Ge, 89 Y, 115 In, 159 Tb, 209 Bi mixed internal standard solution, and then under the set ICP-MS working conditions, the internal standard solution, the series standard solution and the to-be-detected solution are sampled, the ICP-MS detection values obtained respectively are calculated, and the silver ion content of the to-be-detected solution is calculated.

7. The detection method as described in claim 1, characterized in that, The working condition parameters of the ICP-MS are as follows: radio frequency power 1500 W, radio frequency voltage 1.67 V, nebulization chamber temperature 2°C, sampling depth 8.1 mm, carrier gas flow rate 0.85 L / min, compensation gas flow rate 0.21 L / min, and peristaltic pump rate 0.1 rps.

8. A method for analyzing the content of silver ions in precipitation after weather modification operations, characterized by, It comprises the following steps: 1) The detection data of the sample to be tested obtained according to the detection method of any one of claims 1-7, and the detection data is divided into three categories: sample data after aircraft artificial rain / snow operation, sample data after ground artificial rain / snow operation, and sample data after ground artificial hail prevention operation, and the distribution characteristics of the silver ion content in the precipitation under different operation modes are analyzed in combination with a GIS map; 2) Analysis of the influence of the silver ion content on the ecological environment.

9. The analysis method of claim 8, wherein, In step 2), when the silver ion content in the detection results is all lower than 50 μg / L, it indicates that the artificial weather modification operation has no influence on the ecological environment; when the silver ion content in the detection results is all higher than 50 μg / L, the artificial weather modification operation should be suspended first, and whether the detection results are caused by the artificial weather modification operation is analyzed.

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