HR: 17:00h
AN: OS22D-05    [PDF]
TI: In Situ Measurements of Persistent Organic Pollutants in Coastal Waters of the Southern California Bight with a Solid Phase Microextraction (SPME)-Based Method
AU: * Zeng, E Y
EM: EDDYZ@SCCWRP.ORG
AF: SOUTHERN CALIFORNIA COASTAL WATER RESEARCH PROJECT, 7171 FENWICK LANE, WESTMINSTER, CA 92683
AU: Tsukada, D
EM: DAVIDT@SCCWRP.ORG
AF: SOUTHERN CALIFORNIA COASTAL WATER RESEARCH PROJECT, 7171 FENWICK LANE, WESTMINSTER, CA 92683
AU: DIEHL, D
EM: DARIOD@SCCWRP.ORG
AF: SOUTHERN CALIFORNIA COASTAL WATER RESEARCH PROJECT, 7171 FENWICK LANE, WESTMINSTER, CA 92683
AU: Noblet, J A
EM: JIMN@SCCWRP.ORG
AF: SOUTHERN CALIFORNIA COASTAL WATER RESEARCH PROJECT, 7171 FENWICK LANE, WESTMINSTER, CA 92683
AB: Global distribution and fate of persistent organic pollutants (POPs) have become an increasingly significant topic in environmental research, as POPs are potential agents of carcinogenicity and mutagenicity to both humans and non-human species. One of the important transport mechanisms for POPs is advection and dispersion from point sources via oceanic currents. Therefore, measurements of POPs in open coastal waters can provide key information about the global geochemical cycling of POPs. However, because concentrations of POPs in ocean waters are typically in sub-ppt (ng/L) levels or lower, accurate measurement of ambient concentrations is challenging. To obtain sufficient mass that can be detected by current analytical instrumentation, extremely large water volumes (e.g., thousands of liters) have to be processed. Such large sample volumes represent a practical impediment for regional-scale sampling efforts. In an attempt to improve our ability to study the fate of POPs in oceanic environments, we have developed an in-situ sampling approach based on the technique of solid-phase microextraction (SPME) and tested it at several coastal locations within the Southern California Bight. A custom-made SPME sampler consists of a polydimethylsioxane-coated (100-æm thickness) fiber supported on a stainless steel needle and a copper cage shielding the SPME assembly (to slow bacterial growth). We were able to deploy a large number of the samplers simultaneously at different locations and water depths known to contain varying concentrations of DDTs. The SPME samplers were retrieved after about 15 to 30 days of deployment, and the organics partitioned on the SPME fibers were analyzed with GC/MS under optimized chromatographic conditions suitable for SPME analysis. The concentrations of p,p'-DDE (the most dominant component of all DDTs) measured by the in situ SPME approach were very similar as a function of water depth and spatial location as concentrations previously measured by analyzing more than 2000 L of water using an in situ water pumping system. This paper will further present details of sampling logistics, calibration procedures, detection limits, and cost factors, etc., in association with the SPME-based sampling technique.
DE: 1050 Marine geochemistry (4835, 4850)
DE: 1055 Organic geochemistry
DE: 1635 Oceans (4203)
DE: 4857 Pollution
DE: 4894 Instruments and techniques
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting