PARENT SESSION
PS20 - Passive Samplers for POPs
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P196) Field Calibration of XAD-2 Based Passive Air Samplers for Persistent Organic Pollutants.
Shen, Li*,1, Wania, Frank1, Lei, Ying1, Teixeira, Camilla2, Muir, Derek2, 1 University of Toronto at Scarborough, Toronto, Ontario, Canada2 National Water Research Institute, Burlington, Ontario, Canada
ABSTRACT- Responding to a growing need for inexpensive and simple monitoring of persistent organic pollutants (POPs) in the atmosphere, we are presently developing a passive air sampling technique based on the sorption of gaseous pollutants to the sampling medium XAD-2, a styrene-divinylbenzene copolymer. Field testing of XAD-based passive air samplers (PAS) was carried out by deploying a number of PAS at three calibration stations which are in the vicinity of IADN and NCP monitoring sites with ongoing conventional air sampling of POPs. At each of these stations fourteen passive air samplers were installed at the same time, and a pair of samplers was retrieved after variable exposure length and analyzed for PCBs and organic pesticides by GC-ECD. A suitable number of blank samplers were also left at each of these stations and collected for analysis together with the exposed samplers. The results from the field calibration experiments clearly show uptake of various POPs by the PAS within a few weeks of deployment and a linear increase in the amount of chemical collected over a one-year sampling period. Uptake rates for different chemicals were in reasonable agreement with each other. The annual mean air concentrations of POPs derived from the PAS results are comparable with those from HiVol sampling, suggesting that the PAS can be used to derive at least semi-quantitative information on the vapor phase concentrations of POPs in the atmosphere and are suitable for the measurements of long term average concentrations at the levels occurring in remote regions.
Key words: passive air sampling, persistent organic pollutants, XAD-2, field calibration