Air Quality Monitoring

Element offers sampling and analysis of ambient air to determine subsets of the 97 volatile organic compounds (VOCs) included in the 189 hazardous air pollutants (HAPs) listed in Title III of the Clean Air Act Amendments of 1990. Our analysis services can achieve reporting limits around one ppbv for all target compounds depending on the volume of air in the sample canister.

Samples should be collected in specially prepared canisters evacuated to approximately ~30 inches of Mercury. Samples may be collected as a grab sample or as a time-integrated sample by using a flow control device. TO-15 samples can be held for up to 30 days from collection to analysis.

Using EPA Method 18, Element can measure the total mass emissions of VOCs and determine compliance with the emission concentration limit. Method 18 allows for four different sampling options: Direct interface, dilution interface, adsorption tube, and Tedlar bag sampling. Element commonly uses Tedlar bag sampling for analysis conducted in the laboratory.

Element conducts Method 18 analysis via Gas Chromatography with Flame Ionization Detector (GC-FID) for samples collected in Tedlar bags. Element also conducts matrix spike recovery for each source to ensure the overall accuracy of measurements in the analytical procedure. 

Samples should be collected in three or more Tedlar bags. Extra bags provide backup in case of leaks. SUMMA canisters are not allowed under Method 18. There is no technical holding time for Method 18 as long as the recovery study criteria are met.

Element UK laboratories offer analysis of bulk gases such as methane, carbon monoxide, carbon dioxide, oxygen, nitrogen and hydrogen. Element uses Gas Chromatography with Flame Ionization Detector (GC-FID) for this analysis.

Our laboratories can also determine the C1-C7 organic compounds methane, ethane, ethene, propane, pentane, hexane and heptane.

Element UK can provide and analyse adsorption tubes by Thermal desorption GCMS. A variety of tubes (both pumped and passive) are available depending on the analysis required. Analysis includes TPH CWG, 56 VOC target compounds (including BTEX and Naphthalene), target chlorinated compounds or a screen for the top ten peaks.