Influences of relative humidities and temperatures on the collection of C2-C5 aliphatic hydrocarbons with multi-bed (Tenax TA, Carbograph 1TD, Carboxen 1003) sorbent tube method
Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要:
Volatile organic compounds (VOCs) are measured with sorbent tubes followed by thermal desorption (TD) analysis. Water vapor in the atmosphere affects sampling breakthrough and results in low collection efficiency. This paper reports the effect of relative humidity (RH) and temperature on the collection of 57 ozone precursors with a multi-bed tube composed of three different strengths of adsorbents (Tenax TA, Carbograph 1 TD, and Carboxen 1003). Unacceptable breakthrough values for volatile C2-C5aliphatic compounds were observed under high (>60%) RHs. The breakthrough volumes (BV) for C2aliphatic compounds were reduced 13–22 fold under 90% RH. Dry-purge with inert helium gas removes excessive water content before the TD analysis but also causes a maximum of 40% loss of target analytes. Condensation is another pathway for water retention. The tube temperature should be regulated at 5–10��C above the air temperature to minimize condensation under RHs >30%. � 2016 Elsevier Ltd
Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China; Division of Atmosphere Sciences, Desert Research Institute, Reno, NV, United States; Hong Kong Premium Services and Research Laboratory, Lai Chi Kok, Kowloon, Hong Kong
Recommended Citation:
Ho S,S,H,et al. Influences of relative humidities and temperatures on the collection of C2-C5 aliphatic hydrocarbons with multi-bed (Tenax TA, Carbograph 1TD, Carboxen 1003) sorbent tube method[J]. Atmospheric Environment,2017-01-01,151