Device and method for determining dissolved nitrous oxide in water

Abstract

The invention discloses a device and a method for determining dissolved nitrous oxide in water and relates to detection of dissolved nitrous oxide in water. The device comprises a nitrogen cylinder, a first pressure reducing valve, a second pressure reducing valve, a mass flow controller, a flow meter, a six-way valve, a first three-way valve, a second three-way valve, a Nafion tube, a semiconductor cooler, a scavenging conduit, a trapping tube, a Dwarf can, an electric heating tube, a twelve-way valve, a Kelun pump, a sample bottle, a gas chromatograph and a computer. The method comprises a sample introduction stage, a scavenging stage, a trapping stage, a desorption stage and a separation and detection stage. Short time is consumed, the sensitivity is high, the automation degree is high, the operation is simple, the temperature can be subzero 100 DEG C or lower with adoption of the Dwarf can for accommodating liquid nitrogen to serve as a low-temperature source of the trapping tube, and nitrous oxide gas can be trapped on a molecular sieve completely. The electric heating tube can be heated to the temperature of 100 DEG C or higher within 0.5 min, so that the nitrous oxide gas can be desorbed rapidly to enter the gas chromatograph. The concentration of the nitrous oxide gas can be determined accurately by means of the Kelun pump.

Description

technical field [0001] The invention relates to the detection of dissolved nitrous oxide in water, in particular to a device and method for measuring dissolved nitrous oxide in water. Background technique [0002] Nitrous oxide gas has important effects on global climate and atmospheric chemical processes. The greenhouse effect of the equivalent amount of nitrous oxide is 200-300 times that of carbon dioxide. At the same time, its photochemical product NO can be combined with O in the stratosphere 3 reaction, destroying the atmospheric ozone layer (Crutzen, 1970). The concentration of nitrous oxide in the atmosphere is increasing at a rate of about 0.25% per year. For every 5ppb increase in the partial pressure of nitrous oxide in the atmosphere, the corresponding radiative forcing will increase by 11%. The ocean is a net source of nitrous oxide in the atmosphere. The distribution characteristics of nitrous oxide in many oceans and coastal waters around the world have att...

AI Technical Summary

Problems solved by technology

Although early researchers used dry ice cold traps or semiconductor refrigeration technologies to adsorb nitrous oxide gas on molecular sieves, but because the temperature is not low enough, part of the adsorbed nitrous oxide will slowly lose, resulting in inaccurate test results.

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