PH04 Advances in Analysis and Measurements
Exhibit Hall
8:00 AM - Thursday
(PH004A) Status of SPMD development: progress, considerations and research needs.
Huckins, J1, Booij, K2, Cranor, W1, Alvarez, D1, Bartkow, M3, Lebo, J1, Orazio, C1, Clark, R1, Petty, J1, Robertson, G4, 1 USGS - CERC, Columbia, MO, USA2 Royal Netherlands Institute for Sea Research, Texel, The Netherlands3 National Research Centre for Environmental Toxicology, Coopers Plains, Queensland, Australia4 US EPA NERL, Las Vegas, NV, USA
ABSTRACT- At the time of this writing, about 180 articles on lipid-containing semipermeable membrane devices (SPMDs) have been published in peer-reviewed scientific journals. The majority of these papers focus on sampling/monitoring aquatic systems, but there is increasing research being conducted on atmospheric sampling. Progress has been made along a number of research avenues. For example, we present new regression models for the calculation of the SPMD-water/air partition coefficient (Ksw/a) and an overall model for linking SPMD sampling rate (Rsw/a) and Ksw/a to the concentration in the sampler, and thus, water or air concentration. New laboratory-generated Rsa data are presented and compared to data in the literature. This analysis suggests that uptake by SPMDs is generally partly controlled by membrane resistance and partly controlled by air boundary layer resistance, whereas for many of the same compounds in aquatic environments, water side resistance dominates. Finally, the origin of the surficial exterior film, found on some SPMDs after atmospheric deployments, and its role in sampling particulate associated compounds is examined.
Key words: spmds, passive, modeling, photooxidation