Measuring system and method of N2O concentration in air

Abstract

The invention discloses a measuring system and a method of N2O concentration in air. The system is characterized in that: an injection port of a part of analysis and detection and a constant pipe are respectively connected with a first pneumatic valve, and a first chromatographic column is connected with the first pneumatic valve; a second chromatographic column is connected with the first and a second pneumatic valve; two ports of a three-way connection in a part of buffer gas are respectively communicated with an electron capture detector and the second pneumatic valve; another port of the three-way connection is connected with an exit end of a gas switch globe valve to allow the electron capture detector to connect with the buffer gas; the gas switch globe valve is provided with an inlet and an outlet, the inlet of the gas switch globe valve is connected with an outlet of a gas flow control valve, the outlet of the gas flow control valve is connected with an outlet of a pressure-reducing valve, and the inlet of the pressure-reducing valve is connected with a buffer gas steel cylinder. The method is characterized in that: the gas switch globe valve is opened, the gas flow control valve is adjusted to put a buffer gas CO2 with the concentration of 10% in the buffer gas steel cylinder into the electron capture detector with the flow velocity of 2ml / min, and when the detection system turns stable, the sample is analyzed.

Description

technical field [0001] The invention relates to a high-sensitivity, accurate determination of N in the atmosphere 2 Gas chromatography measurement system for O concentration, suitable for environmental and scientific research on atmospheric N 2 Concentration monitoring and flux studies of O. Background technique [0002] Nitrous oxide (N 2 O) is second only to carbon dioxide (CO 2 ) and methane (CH 4 ), atmospheric trace greenhouse gases, global N 2 The estimated value of emission intensity in O year has great uncertainty, ranging from 8.5 to 27.7 Tg N yr -1 . The uncertainty of the estimated value is due to the imperfect mechanism of the estimation model on the one hand, and the lack of accuracy and representativeness of the observed data on the other hand. Both of these aspects must depend on the knowledge of the atmospheric N 2 Accurate quantification of O concentration. [0003] Currently the most widely used N in the world 2 O concentration analysis method is ...

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Problems solved by technology

but only use N 2 When used as carrier gas, N 2 The detection sensitivity of O is low, and the CO present in the gas sample 2 also interfere with N 2 Accurate measurement of O (zheng et al., 2008)

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