Advances in ultra-trace air toxics analysis: Cryogen-free canister pre-concentration and GC–MS for US EPA Method TO-15A
Application Note 169
In the USA, monitoring of a specific list of hazardous air pollutants has been carried out in line with EPA Method TO-15 since it was published for monitoring ‘air toxics’ in 1999. In 2020, an update to this method was released to better address the low concentrations often seen within ambient air. This is US EPA method TO-15A.
This Application Note describes the automated, high-performance gas chromatography–mass spectrometry (GC–MS) analysis of humid ‘air toxics’ samples in canisters, using a cryogen-free system for preconcentration and thermal desorption (TD).
Detection of 75 target compounds – ranging in volatility from propene to naphthalene – is demonstrated, with excellent analytical performance, and all well within the criteria set out in US EPA Method TO-15A.
The Note shows how the UNITY–CIA Advantage-xr Kori-xr system – combining canister automation, pre-concentration, thermal desorption and selective water removal with Markes’ Dry-Focus3 technology – meets the requirements of US EPA Method TO-15A.
Furthermore, excellent analytical performance, exceptional background levels and high sensitivity with an average instrument detection limit of 1.64 pptv for all 75 compounds, while significantly improving sample throughput from 3 to 5 samples every two hours is demonstrated.