Sample preparation method used for determining abundance of <15>N isotope of nitrite

Abstract

The invention relates to a sample preparation method used for determining abundance of a <15>N isotope of nitrite. The sample preparation method comprises the following steps: loading a sample, namelyloading a <15>N-labeled to-be-prepared sample and aqueous solution of a reducing agent into a first bulb of a double bulb reaction tube, and loading an acidic material into a second bulb of the double bulb reaction tube; preparing a <15>NO gas, namely maintaining vacuum degree, and adding the acidic material in the second bulb into the first bulb, so that the <15>NO gas is generated; detecting, namely after the vacuum degree of a pipeline between a vacuum plug valve and a gas isotope ratio mass spectrometer is reduced to be below 2*10<-5>Pa, opening the vacuum plug valve, and introducing the<15>NO gas in the first bulb into the gas isotope ratio mass spectrometer; setting detection parameters of the gas isotope ratio mass spectrometer, detecting a relative intensity when mass numbers are30 and 31, and performing a parallel test for multiple times; and calculating an abundance value of the <15>N isotope. Compared with the prior art, the sample preparation method provided by the invention has the advantages that an operation process is safe and reliable, sample pretreatment time is greatly shortened, economic cost is low and test data accuracy and precision are high.

Description

technical field

[0001] The present invention relates to a 15 N isotopic abundance detection method, especially related to the determination of nitrite 15 Sample preparation method for N isotopic abundance. Background technique

[0002] The increase of reactive nitrogen improves the productivity of the ecosystem in the short term and accumulates more biomass. However, with the rapid increase of nitrogen fertilizer application in farmland, a large part of the reactive nitrogen applied to farmland cannot be completely absorbed and utilized by crops. Instead, it is released into the environment in the form of various reactive nitrogen, which brings serious environmental problems such as eutrophication of surface water, nitrate pollution of groundwater, ozone layer destruction and acid rain, and changes the balance of nitrogen cycle in the global ecosystem. Reducing the anthropogenic emission of reactive nitrogen is a serious challenge for human beings.

[0003] An example of ...

Examples

Embodiment 1

[0052] Sodium nitrite- 15 N chemical reagent isotope abundance analysis, comprising the following steps:

[0053] (1) Preparation 15 NO gas

[0054] The reaction equipment adopted in the present invention is such as figure 1 In the double-ball reaction tube shown, one side of the double-ball reaction tube is two bulbs communicated by pipelines, and the liquid in the second bulb 2 can be entered into the first bulb 3 by tilting, and the double-ball reaction The other side of the tube can communicate with other equipment outside.

[0055] The sampling connector adopted in the present invention is as figure 2 As shown, there are two vacuum cock valves 5 in series in sequence, one end of which can be connected to the vacuum system or testing equipment, and the other end can be connected to the inlet port 1 of the double-ball reaction tube to vacuumize the double-ball reaction tube, and pass Close the vacuum stopcock 5 to realize the maintenance of vacuum degree.

[0056] Ta...

Embodiment 2

[0062] Nitrite in water samples 15 N isotope abundance analysis, including the following steps:

[0063] (1) Pretreatment of water quality samples

[0064] Water quality samples need to add a small amount of sodium carbonate solution to make the pH 7-8. When the nitrite content is lower than 20ppm (volume> 50mL), heat and concentrate at 90°C to about 6mL.

[0065] (2) Preparation 15 NO gas

[0066] Take 0.5mL of 2mol / L potassium iodide solution and 2mL of the treated sample in the first bulb 3 of the double bulb reaction tube, add 2mL of 5mol / L acetic acid solution in the second bulb 2, connect the inlet port 4 of the sampling connector Connect the vacuum system, the outlet port 6 of the sampling connector is connected to the inlet port 1 of the double-ball reaction tube, after the vacuum degree is lower than 50Pa, close the vacuum cock valve 5, and add the sulfuric acid in the second bulb 2 to the first bulb 3, and placed in a hot water bath at 60°C to 80°C for 5 minutes,...

Embodiment 3

[0072] Nitrite in soil samples 15 N isotope abundance analysis, including the following steps:

[0073] (1) Pretreatment of soil samples

[0074] The soil samples were dried at 70°C, crushed and ground after 3 hours, passed through a 0.25mm aperture soil sieve, and 10g of soil was added to 10mL of aqueous solution to adjust the pH to 7-8 with sodium carbonate, ultrasonically dissolved, and after standing for 30min, take the supernatant and seal it for later use. use;

[0075] (2) Preparation 15 NO gas

[0076] Take 0.5mL of 2mol / L potassium iodide solution and 2mL of the treated sample in the first bulb 3 of the double bulb reaction tube, add 2mL of 5mol / L acetic acid solution in the second bulb 2, connect the inlet port 4 of the sampling connector Connect the vacuum system, the outlet port 6 of the sampling connector is connected to the inlet port 1 of the double-ball reaction tube, after the vacuum degree is lower than 50Pa, close the vacuum cock valve 5, and add the sul...

technical field

[0001] The present invention relates to a 15 N isotopic abundance detection method, especially related to the determination of nitrite 15 Sample preparation method for N isotopic abundance. Background technique

[0002] The increase of reactive nitrogen improves the productivity of the ecosystem in the short term and accumulates more biomass. However, with the rapid increase of nitrogen fertilizer application in farmland, a large part of the reactive nitrogen applied to farmland cannot be completely absorbed and utilized by crops. Instead, it is released into the environment in the form of various reactive nitrogen, which brings serious environmental problems such as eutrophication of surface water, nitrate pollution of groundwater, ozone layer destruction and acid rain, and changes the balance of nitrogen cycle in the global ecosystem. Reducing the anthropogenic emission of reactive nitrogen is a serious challenge for human beings.

[0003] An example of ...

Examples

Embodiment 1

[0052] Sodium nitrite- 15 N chemical reagent isotope abundance analysis, comprising the following steps:

[0053] (1) Preparation 15 NO gas

[0054] The reaction equipment adopted in the present invention is such as figure 1 In the double-ball reaction tube shown, one side of the double-ball reaction tube is two bulbs communicated by pipelines, and the liquid in the second bulb 2 can be entered into the first bulb 3 by tilting, and the double-ball reaction The other side of the tube can communicate with other equipment outside.

[0055] The sampling connector adopted in the present invention is as figure 2 As shown, there are two vacuum cock valves 5 in series in sequence, one end of which can be connected to the vacuum system or testing equipment, and the other end can be connected to the inlet port 1 of the double-ball reaction tube to vacuumize the double-ball reaction tube, and pass Close the vacuum stopcock 5 to realize the maintenance of vacuum degree.

[0056] Ta...

Embodiment 2

[0062] Nitrite in water samples 15 N isotope abundance analysis, including the following steps:

[0063] (1) Pretreatment of water quality samples

[0064] Water quality samples need to add a small amount of sodium carbonate solution to make the pH 7-8. When the nitrite content is lower than 20ppm (volume> 50mL), heat and concentrate at 90°C to about 6mL.

[0065] (2) Preparation 15 NO gas

[0066] Take 0.5mL of 2mol / L potassium iodide solution and 2mL of the treated sample in the first bulb 3 of the double bulb reaction tube, add 2mL of 5mol / L acetic acid solution in the second bulb 2, connect the inlet port 4 of the sampling connector Connect the vacuum system, the outlet port 6 of the sampling connector is connected to the inlet port 1 of the double-ball reaction tube, after the vacuum degree is lower than 50Pa, close the vacuum cock valve 5, and add the sulfuric acid in the second bulb 2 to the first bulb 3, and placed in a hot water bath at 60°C to 80°C for 5 minutes,...

Embodiment 3

[0072] Nitrite in soil samples 15 N isotope abundance analysis, including the following steps:

[0073] (1) Pretreatment of soil samples

[0074] The soil samples were dried at 70°C, crushed and ground after 3 hours, passed through a 0.25mm aperture soil sieve, and 10g of soil was added to 10mL of aqueous solution to adjust the pH to 7-8 with sodium carbonate, ultrasonically dissolved, and after standing for 30min, take the supernatant and seal it for later use. use;

[0075] (2) Preparation 15 NO gas

[0076] Take 0.5mL of 2mol / L potassium iodide solution and 2mL of the treated sample in the first bulb 3 of the double bulb reaction tube, add 2mL of 5mol / L acetic acid solution in the second bulb 2, connect the inlet port 4 of the sampling connector Connect the vacuum system, the outlet port 6 of the sampling connector is connected to the inlet port 1 of the double-ball reaction tube, after the vacuum degree is lower than 50Pa, close the vacuum cock valve 5, and add the sul...

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