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 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

Simplified model of the partitioning processes that control the bioavailability of PCB

Uptake Model

Linear: Log Kow ≥ 4.5

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

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

0 2 4 6 8 10

LDPE, POM, PDMSSPMD

PISCESnd-SPME

MESCOTRIMPS

EcoscopeCHEMCATCHER

Solvent-f illed membranesTLC plates

Ceramic dosimeter PDB

TWA-SPMEPOCISuPSD

Superfund Chemical List

logKow

Porous membrane

Absorbent phase

Cap CuO Filter

O-ring

Goal: to develop a universal PSD (uPSD)Goal: to develop a universal PSD (uPSD)

Measuring freely dissolved PCB using POM and SPME

SPME POM PDMS

Polymer and soil-water slurry were allowed to reach equilibrium