US EPA Method TO-15 involves sampling of ambient air using canisters followed by thermal desorption pre-concentration, and GC–MS or GC–FID analysis.
It is widely used by commercial laboratories for analysis of volatile organic compounds (VOCs) in urban and industrial settings, especially in the USA and Asia.
But traditional canister pre-concentration technologies are challenged by the ever-greater range of analytes and concentrations of interest, and by the range of temperatures and humidities at sampling locations.
Markes has published a new study that demonstrates the excellent performance of its ground-breaking cryogen-free Dry-Focus3™ pre-concentration technology for confident GC–MS canister analysis of trace-level ‘air toxics’ in humid environments, in accordance with US EPA Method TO-15 and with ‘trace TO-15’ methods stipulating lower detection limits.
We analysed a 65-component TO-15 mix with 100% relative humidity, containing compounds ranging in volatility from propene to naphthalene, and assessed linearity, detection limits and reproducibility.
Overall performance was well within the requirements of Method TO-15 and the New Jersey ‘Low-level Method TO-15’, with key features being: