The EPA’s PAMS program (Photochemical Assessment Monitoring Stations network) has been enforced since 1993. In the program, US states and local environmental agencies are required to measure volatile hydrocarbons in urban areas affected by significant ground-level ozone pollution.
Both canister and on-line sampling are useful techniques for monitoring trace-level vapors in ambient air using thermal desorption (TD). Canister sampling collects air into a canister followed by off-line TD–GC analysis. On-line sampling transfers air directly into the TD–GC system for real-time analysis. Both methods are useful alternatives to tube-based sampling when the compounds of interest are too volatile to be retained by sorbent tubes at ambient temperature.
Sampling air streams with high humidity can have some significant issues. Specifically, lowered sorbent breakthrough volumes and cold-trap ice formation. This can lead to lower maximum sample volumes and increased method detection limits. Additionally, the presence of water in the GC column can cause poor chromatography.
Removal of water from samples is important. But existing approaches have major drawbacks. For example, certain polar species and ultra-volatiles can be lost when using Nafion™ dryers, while very volatile compounds can be lost when using a trap temperature of 25°C.
Are you ready and able to tackle the EPA’s PAMS program? We’ll help you get there. During this live webinar, we’ll describe the Markes-Agilent Auto-GC set up for PAMS analysis. Also, we’ll share how an innovative water-management device that allows the new PAMS-priority compounds and others to be analyzed. The system selectively removes water before analyte focusing. This allows high-sensitivity on-line analysis of polar species, oxygenates, pinenes, and all other typical VVOCs and VOCs in humid environments.
Webinar recorded May 9, 2017
Duration: 45 minutes
Presenting Partner: Markes International
Environmental Specialist, Markes International
Nicola is the environmental specialist at Markes International, leading specialists in thermal desorption technology. Nicola has been with Markes for 10 years and prior to joining completed her PhD at the University of York. As a student, Nicola specialized in Atmospheric and Analytical Chemistry and was involved in a number of international field campaigns investigating transportation and transformation of VOCs in the atmosphere.