Determination of uptake kinetics (Sampling rates) by lipid-containing semipermeable membrane devices (SPMDs) for polycyclic aromatic hydrocarbons (PAHs) in water

The use of lipid-containing semipermeable membrane devices (SPMDs) is becom ing commonplace, but very little sampling rate data are available for the e stimation of ambient contaminant concentrations from analyte levels in expo sed SPMDs. We determined the aqueous sampling rates (R(S)s; expressed as ef fective volumes of water extracted daily) of the standard (commercially ava ilable design) 1-g triolein SPMD for 15 of the priority pollutant (PP) poly cyclic aromatic hydrocarbons (PAHs) at multiple temperatures and concentrat ions. Under the experimental conditions of this study, recovery-corrected R -S values for PP PAHs ranged from approximate to 1.0 to 8.0 L/d. These valu es would be expected to be influenced by significant changes (relative to t his study) in water temperature, degree of biofouling, and current velocity -turbulence. Included in this paper is a discussion of the effects of tempe rature and octanol-water partition coefficient (K-OW); the impacts of biofo uling and hydrodynamics are reported separately. Overall, SPMDs responded p roportionally to aqueous PAH concentrations; i.e., SPMD R-S values and SPMD -water concentration factors were independent of aqueous concentrations. Te mperature effects (10, 18, and 26 degrees C) on R-S values appeared to be c omplex but were relatively small.