Grab Sampling

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    01-Jan-2016
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Grab Sampling. Collect water, transport to lab, extract, preconcentrate, analyze Offers “ accepted ” approach and time-point data, but has disadvantages “ Snapshot ” in time No information on chronic exposure or bioavailability Large amount of water and solvent needed - PowerPoint PPT Presentation

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  • Grab SamplingCollect water, transport to lab, extract, preconcentrate, analyze

    Offers accepted approach and time-point data, but has disadvantages

    Snapshot in time No information on chronic exposure or bioavailability Large amount of water and solvent needed Often has insufficient sensitivity

  • P: Parent PCBM: PCB metabolitesKPSW and KMSW: PSD-water partition coefficients of P and M KPOC and KMOC: oil or other organic carbon sorption coefficients of P and M BCF: bioconcentration factorBMF: biomagnification factorMET: metabolic clearanceKPSD and KOILSimplified model of the partitioning processes that control the bioavailability of PCB

  • Uptake Model

    Linear: Log Kow 4.5Integrative ApproachProvides estimation of TWA during a specific exposure period

    Chemical residues from episodic chemical events are retained

    Only occurs in linear phase

    Requires calibration data Effective Sampling Rate (Rs)

    Rs = N / Cw * t

    Cw = N / Rs * t

    T50 = - ln 0.5 KPSDVPSD / Rs

  • Overall Goal: Advance design/use of PSDs to be more universal, quantitative, and used in site/risk assessment

  • Goal: to develop a universal PSD (uPSD)

  • Measuring freely dissolved PCB using POM and SPMESPMEPOMPDMSPolymer and soil-water slurry were allowed to reach equilibrium

    ***Swanquarter- by mouth of river- tidal, blue-crab habitat(Delete in favor of Washington slide?- make decision based on time)