Method for detecting nitrogen dioxide gas by using solid reagents in field environment

Abstract

The invention relates to a method for detecting nitrogen dioxide gas by using solid reagents in a field environment. The method comprises the following steps: pouring a reagent A into a plastic centrifuge tube, adding pure water, dissolving, adding a reagent B, dissolving, adding a reagent C, shaking uniformly, and adding pure water to form an absorption solution for detecting nitrogen dioxide; transferring the absorption solution into a brown porous glass plate absorption tube, and connecting a sampling pump to a gas outlet end of the absorption tube to react with nitrogen-dioxide-containing gas; and standing the sample in a dark place for 20 minutes, and carrying out colorimetric determination on the sample by an outdoor minitype colorimeter. The method solves the problem that the absorption solution and color development solution in the prior art have requirements for the storage environment and are short in shelf life.

Description

Technical field: [0001] The invention relates to a method for detecting the concentration of nitrogen dioxide gas, and further relates to a method for detecting nitrogen dioxide gas with a solid reagent in a field environment far away from a laboratory. Background technique: [0002] Nitrogen dioxide is a common harmful gas in the ambient air. There are many kinds of existing gas detection methods. [0003] (1) Gas detection tube method: the advantage is that the detection speed is fast, and the disadvantage is that the accuracy is not high and the error is large. It is generally used for high-concentration gas detection such as emergencies and workshop environments. [0004] (2) Portable direct-reading instrument method: the advantage is that the detection speed is fast, but the electrochemical sensor is more expensive and has a short service life, usually only 2 years and requires regular calibration with standard gas. [0005] (3) Two methods are often used in laborator...

AI Technical Summary

Problems solved by technology

[0003] (1) Gas detection tube method: the advantage is that the detection speed is fast, and the disadvantage is that the accuracy is not high and the error is large. It is generally used for high-concentration gas detection such as emergencies and workshop environments.

[0004] (2) Portable direct-reading instrument method: the advantage is that the detection speed is fast, but the electrochemical sensor is more expensive and has a short service life, usually only 2 years and requires regular calibration with standard gas

[0005] (3) Two methods are often used in laboratory testing: one is to use large-scale equipment, which is expensive and has high maintenance and testing costs

[0006] (1) The p-aminobenzenesulfonic acid in the absorption solution and the color development solution is insoluble in water at room temperature, and needs to be dissolved in hot water at 40--50°C when preparing in the laboratory, and it is not easy to operate in the field environment

[0007] (2) NO under laboratory conditions 2 The chromogenic solution should be stored in a closed brown bottle after preparation, and it can be stored at a temperature below 25°C for 3 months; the absorption solution is prepared when it is used, and it is diluted from the chromogenic solution. Multiple dilutions will increase the chromogenic solution. Pollution probability

[0008] When going out for on-site sampling and testing, it is necessary to carry a large amount of NO detection 2 The liquid absorbing liquid or color developing liquid, the absorbing liquid or color developing liquid has requirements on storage conditions and temperature, and the storage period is short, giving NO 2 The carrying and transportation of testing reagents and the collection and testing of samples bring inconvenience

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