Improved Chemical Amplification Instrument by Using a Nafion Dryer as an Amplification Reactor for Quantifying Atmospheric Peroxy Radicals under Ambient Conditions - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue Analytical Chemistry Année : 2019

Improved Chemical Amplification Instrument by Using a Nafion Dryer as an Amplification Reactor for Quantifying Atmospheric Peroxy Radicals under Ambient Conditions

Résumé

In our previous work (Yang et al. Anal. Chem. 2018, 90 (5), 3307−3312), we reported that a large diameter Nafion dryer can be used in the PERCA (PEroxy Radical Chemical Amplification) technique to minimize the impact of water vapor on the chain length (CL). By using a Nafion dryer, the sample was first dried to a low relative humidity (RH) and was then drawn into a FEP (fluorinated ethylene propylene) flow reactor tube to start the amplification cycles for peroxy radical measurement. This method provides a promising and simple method to minimize the sensitivity of CL to water vapor. However, there is a trade-off between inlet radical losses and moisture removal efficiency under high ambient RH conditions. In this paper, we report a further improvement by removing the inlet Nafion dryer and using it directly as an amplifier. The sample was drawn into the Nafion dryer directly without preconditioning to reduce inlet losses; the amplification and HO2 reformation cycles were started in the Nafion dryer. The CL value at 3% RHinlet was about 150. A linear relationship between CL and RHinlet up to 87% RH was observed. Low loss of the CL under high RHinlet (about 10% reduction at 87% RH) was achieved. As a result, the modified system can largely remove the uncertainty of the CL arising from water vapor under most ambient conditions.

Domaines

Chimie

Dates et versions

hal-02322030 , version 1 (21-10-2019)

Identifiants

Citer

Chengqiang Yang, Weixiong Zhao, Bo Fang, Hui Yu, Xuezhe Xu, et al.. Improved Chemical Amplification Instrument by Using a Nafion Dryer as an Amplification Reactor for Quantifying Atmospheric Peroxy Radicals under Ambient Conditions. Analytical Chemistry, 2019, 91 (1), pp.776-779. ⟨10.1021/acs.analchem.8b04907⟩. ⟨hal-02322030⟩
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