|Abstract Title:||Dynamic generation of trace vapour standards of PAHs in nitrogen carrier gas using diffusion tubes|
|Presenter Name:||Dr John Thompson|
|Co-authors:||Mr Daniel Blenkhorn|
|Company/Organisation:||Tracer Measurement Systems Ltd|
|Session Choice:||Standards & Quality Assurance|
Abstract Information :
Until recently, it has been difficult to dynamically generate trace vapour standards of SVOCs such as PAHs because of lack of suitable thermostat systems and because permeation tubes are unsuitable for use with SVOCs. Our recent studies of dynamic generation of trace vapour standards of oxygen-sensitive VOCs such as MVK using diffusion tubes are relevant, as PAHs are oxygen-sensitive at the temperatures needed to generate trace vapour standards, hence our use of nitrogen as carrier gas rather than air.
We report using the Tracer Cert™ refillable diffusion tubes at temperatures between 400K and 470K to dynamically generate vapours of several environmentally significant PAHs, including benzo-a-pyrene, fluoranthene, etc., at trace concentrations in the ppb and ppt ranges and their use in vapour phase analysis for both calibration and for exploration of the ion-molecule chemistry, using H3O+ and O2+ reagent ions, with a Kore PTR TOF MS fitted with an RF-powered Ion Funnel, for applications in environmental monitoring.