Two high-speed, portable GC systems designed for the measurement of non-methane hydrocarbons and PAN: results from the Jungfraujoch High Altitude Observatory.
Near real-time measurements of light non-methane hydrocarbons (NMHCs) and peroxyacetyl nitrate (PAN) have been performed in the free troposphere using two fast gas chromatography (GC) instruments designed for use on aircraft. A GC-helium ionisation detector (HID) system measured 15 C(2)-C(5) hydrocarbons with 5 min time resolution and a dual channel GC-Electron Capture Detector (ECD) measured PAN with 90 s resolution. Both instruments had low parts per trillion by volume (pptV) detection limits and ran continuously at the remote Jungfraujoch (JFJ) research station in the Swiss Alps (46.55[degree]N, 7.98[degree]E), 3580 m above mean sea level (AMSL), during February/March 2003. Carbon monoxide, ozone, nitrogen oxide and nitrogen dioxide and all odd nitrogen species (NO(y)) were also measured continuously. Hydrocarbons and CO were strongly correlated in all air-masses whilst PAN exhibited both positive and negative correlations with respect to O(3), dependent on age and origin of the air-mass sampled. PAN was found to contribute [similar]20% to the NO(y) sampled on average. The experiment, as well as providing interesting datasets from this remote location, also demonstrated that when optimised, GC techniques have the potential to measure at a time resolution significantly greater than is traditionally considered, with high sensitivity and low uncertainty.
Whalley
L K
LK
School of Chemistry, University of Leeds, Leeds, UK.
Lewis
A C
AC
McQuaid
J B
JB
Purvis
R M
RM
Lee
J D
JD
Stemmler
K
K
Zellweger
C
C
Ridgeon
P
P
D000393:Air Pollutants / Q000032:analysis*; D001331:Automation; D002849:Chromatography, Gas / Q000295:instrumentation*; D004784:Environmental Monitoring / Q000295:instrumentation*; D004867:Equipment Design; D006838:Hydrocarbons / Q000032:analysis*; D010463:Peracetic Acid / Q000031:analogs & derivatives* / Q000032:analysis*; D012680:Sensitivity and Specificity
D000393:Air Pollutants; D006838:Hydrocarbons; D010463:Peracetic Acid; C004185:peroxyacetyl nitrate