CICEET Progress Report for the period 9/01/08 Through 2/15/09
Project Title: Using passive samplers to detect emerging contaminants and predict their bioavailability to benthic organisms
Principal Investigator(s): Dr. Rainer Lohmann (URI-GSO)
Project Start Date: 09/01/2008
Project Objectives for This Reporting Period
Objectives
A) Validate PE samplers for alkylphenols, triclosan and PBDEs
B) Plan outreach activities for summer of 2009
Tasks to meet objectives
A.i) Establish analytical methods for the detection of alkylphenols, triclosan and PBDEs
A.ii) Determine PE-water partitioning constants as a function of temperature, salinity and pH
A.iii) Field deployment of PEs in Narragansett Bay
Progress on Tasks
A.i) Establish analytical methods for the detection of alkylphenols, triclosan and PBDEs
The method for derivatizing the alkylphenols and triclosan are established, while we have postponed until later this year the analytical work on PBDEs. On the other hand, we expanded to include bisphenol A in our list of analytes, as it is of current interest, and it similar in structure to the alkylphenols.
Currrently, native analytes studied are as follows: triclosan, methyl-triclosan, nonylphenols, octylphenols, and bisphenol A. Internal standards are carbon labeled Triclosan, Methyl-Triclosan, n-nonylphenol, and bisphenol A. The performance reference compounds are deuterated nonylphenol, octylphenol, and bisphenol A (and brominated biphenyls for PBDEs).
To deactivate the hydroxyl group, all standards (and samples) are blown to dryness using a steady stream of nitrogen and then derivatized using MTBSTFA + 1% TBDMCS (N-Methyl-N-[tert-butyldimethyl-silyl]trifluoroacetimide + 1% tert-Butyldimethylchlorosilane) which converts the compounds to tert-butyldimethyl silyl derivatives of the parent compounds. Standards and samples are then analyzed on an Agilent 6890 GC with 5973 MSD. The PE samplers to be deployed this summer will contain PRCs for PBDEs, so that we can derive water column and porewater concentrations of PBDEs for all samples taken this summer.
A.ii) Determine PE-water partitioning constants as a function of temperature, salinity and pH A first set of laboratory experiments to determine the PE-water partitioning constants are undertaken, with the remainder to be completed over the next few months. In addition, we have set up experiments to determine the hexadecane-water partitioning constants for emerging contaminants, which will serve as verification/correlation properties of the PE-water partitioning data.
A.iii) Field deployment of PEs in Narragansett Bay As the official start to our project was in September 2008, we decided that it was better to wait with PE deployments until the spring of 2009, by which time we will have finalized our methods.
Have the results/data gathered during this reporting period changed the project objectives when compared to your original proposal? Please explain.
No
Dissemination activities during this reporting period (please include the number of participants where applicable):
Outreach Activities
Convened an outreach meeting w/ NBNERR Partners on Feb. 24.
i) Outlined NBNERR involvement in research and dissemination activity
ii) Agreed on schedule changes: 2009 Workshop moved to August (formerly April) to accommodate field work season and the collection of preliminary results
iii) Drafted list of potential workshop attendees (expanded upon list derived from quarterly end-user meeting)
iv) Brainstormed potential workshop agenda
v) Agreed upon project team’s involvement in NBNERR-based outreach activity in order to boost dissemination to K-12 school groups
We brainstormed an outreach work plan, and discussed how to integrate outreach objectives with fieldwork schedule.
Contact with End Users
We have been in regular contact with our endusers at the U.S. EPA. Based on their guidance we decided to initially focus our analytical efforts establishing methods for the detection of alkylphenols and triclosan.
We convened a formal quarterly meeting w/ end user (R. Burgess, EPA) on Jan. 30
i) Agreed on schedule changes
ii) Moved 2009 Workshop to August (formerly April) to accommodate field work season and the collection of preliminary results
iii) Brainstormed potential attendees
iv) Brainstormed potential workshop agenda
Student activity (e.g. theses, dissertations, etc.) on the project (please identify students as graduate or undergraduate)
Victoria P. Sacks is employed by this project as a M.Sc. student, which will form the basis of her thesis work.
Difficulties
We had some delay in obtaining the analytical standards that we wanted, as some needed to be shipped in from Europe. Initially, we aimed to measure alkylphenols without derivatization, which would have saved us a lot of time and cost. Unfortunately, this would have only worked at very high concentrations of alkylphenols (at above 5 ng per injection) and we abandoned this potential shortcut. Hence, we now use a derivatization agent (see above). This has resulted in a delayed beginning of the PE-water partitioning constant experiments as a function of temperature, salinity and pH. We expect to finish these as planned in the next reporting period.
Data Generated to date
We improved our method to load PRCs into PE sheets, by spinning the PE samplers in a methanol-water mixture using a stirbar. After 2 weeks of agitation, our relative standard deviations for a wide range of PRCs < 10%. Hence we foresee no difficulties in preparing PE samplers with our PRCs for the deployment season.
Project Objectives for Next Reporting Period
Objectives
Measure water column and porewater concentrations of emerging contaminants in Narragansett Bay water and sediments
Work Plan to Meet Objectives
C.i) Determine PE-water partitioning constants as a function of temperature, salinity and pH on-going work throughout the reporting period.
C.ii) reproducibly load PE-samplers with performance reference compounds for alkylphenols, triclosan and PDBEs.
C.iii) Deploy PE samplers in the water column of selected locations in Narragansett Bay (near SWTPs, our reference NERRS site, Prudence Island)
C.iv) Compare the results from PEs to those obtained using POCIS
C.v) Collect sediment and incubate with PE-samplers in the laboratory
(opportunistic biota collection during the sediment collection)
C.vi) Derive water column and porewater concentrations of emerging contaminants in Narragansett Bay
Dissemination Objectives for next reporting period
i) Will convene quarterly meeting w/ end user
ii) Will finalize workshop planning/agenda
iii) Will invite workshop attendees
iv) Will photo document field work to provide imagery for presentations/manual
v) Will convene August workshop
vi) Will conduct evaluation of workshop (surveying of attendees)
vi) Will convene final quarterly meeting w/ end user and NBNERR partners to plan for 2010 outreach/dissemination activity.
vii) Poster presentation at SETAC Europe meeting (Gothenburg in June’09) on the use of PE samplers to detect emerging contaminants in water/porewater.
Overall Project Timeline Update
The first user workshop has been moved to August’09.
Quantification of PBDEs will begin in the fall’09.
Water column deployments will begin in May’09.
Expenditures
Expenditure is within the range anticipated.
End User/ Producer/ Adopter Advisor(s) Feedback
End User Advisor: Dr. Robert Burgess
Organization: U.S. EPA
Location: Narragansett
Phone number: 401-782-3106
E-mail: Burgess.Robert@epamail.epa.gov
At this stage, what are the potential applications for this research? Please discuss how you and others could potentially use the technology.
The U.S. EPA’s Office of Water and Office of Research and Development are very interested in the fate of emerging contaminants in the aquatic environment. However, because they are released at relatively low concentrations, conventional sampling techniques (e.g., collection and extraction of water samples) are likely to generate highly variable concentration data of limited usefulness. The passive sampler technology being evaluated in this research is addressing in a direct fashion the in situ measurement of several important emerging contaminants in the water column, sediments and, if possible, organisms. In this way, the research addresses the three critical aquatic phases describing the fate of anthropogenic contaminants. One of the principle applications of this research is in ecological risk assessment to quantify the exposure to emerging contaminants aquatic organisms’ experience.
At this stage in the research, it is too soon to discuss the potential applications in any detail except to indicate the investigators are doing the exact type of preliminary research necessary to later successfully apply the results.
What are the key challenges to application of this technology? Please consider the technology itself as well as issues related to regulation, politics, socio-economic pressures, trends in the field etc.
From the regulatory perspective, the key challenges are related to the types of compounds being investigated in this research. Several types of passive samplers have been applied to measure the legacy-type compounds; for example, the PCBs, PAHs and dioxins/furans. Very little passive sampler work has been conducted with the more water soluble emerging contaminants under investigation in this study (e.g., triclosan, nonylphenol). A variety of technical challenges result from working with these compounds ranging from how to analyze them to how do they partition in a polyethylene-water system. Because of these technical challenges, some end users of the results of this research may express some skepticism about applying the passive sampler technology for these types of compounds. However, as noted above, the researchers are conducting this study in a way to address many of the technical challenges; this approach to the research will translate into significant confidence by the end users that the passive sampler technology is effective and useful with these emerging contaminants.
Has anything changed about this project's potential applicability since the last reporting period (not applicable to the first Progress Report)?
Not applicable.
Questions/comments/ suggestions for the researchers?
(1) The following text from the progress report indicates that PRCs will be used with the PBDEs:
"The PE samplers to be deployed this summer will contain PRCs for PBDEs, so that we can derive water column and porewater concentrations of PBDEs for all samples taken this summer."
This statement is also true for the triclosan, nonylphenol and bisphenol A is that correct?
(2) The use of the hexadecane (HD)-water KPs to evaluate the PE-water partitioning is very interesting, please elaborate further on what you expect to observe (e.g., the KPPE-water and KPHD-water to be very similar?). How is this more useful than KOW?
(3) The POCIS comparison to the polyethylene will be very interesting will that comparison be performed primarily in the water column deployments? Can POCIS be used in a sediment deployments (I don’t think so).
PI Response to End User Advisor Feedback
(1) Yes, indeed, we will have PRCs for triclosan, nonylphenol, bisphenol A and PBDEs included. The performance reference compounds are deuterated nonylphenol, octylphenol, and bisphenol A (and brominated biphenyls for PBDEs).
(2) As we discussed in our original proposal, Kow is a good correlator for Kpe-w for non-poplar organic compounds (as they can only interact via van-der Waals forces in both phases). In contrast, polar compounds, like alkylphenols, triclosan or bisphenol A, however, will undergo additional interaction with octanol but not with the polyethylene. Hence we need some alternative partitioning constant to verify that our Kpe-w are in the right order of magnitude, and hexadecane-water partitioning will give us these numbers.
(3) We plan to only co-deploy POCIS and PEs in the water column. At this stage, it does not seem that POCIS are useful/practical for sediment deployments.