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Grab Sampling

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

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Grab Sampling

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  1. 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 • Often has insufficient sensitivity

  2. Simplified model of the partitioning processes that control the bioavailability of PCB P: Parent PCB M: PCB metabolites KPSW 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 factor BMF: biomagnification factor MET: metabolic clearance KPSD and KOIL

  3. Uptake Model • Integrative Approach • Provides 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 Linear: Log Kow ≥ 4.5

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

  5. O-ring Porous membrane Absorbent phase Cap CuO Filter Goal: to develop a universal PSD (uPSD)

  6. Measuring freely dissolved PCB using POM and SPME SPME POM PDMS Polymer and soil-water slurry were allowed to reach equilibrium

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