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 becoming commonplace, but very little sampling rate data are available for the estimation of ambient contaminant concentrations from analyte levels in exposed SPMDs. We determined the aqueous sampling rates (R(S)s; expressed as effective volumes of water extracted daily) of the standard (commercially available design) 1-g triolein SPMD for 15 of the priority pollutant (PP) polycyclic aromatic hydrocarbons (PAHs) at multiple temperatures and concentrations. 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 values would be expected to be influenced by significant changes (relative to this study) in water temperature, degree of biofouling, and current velocity-turbulence. Included in this paper is a discussion of the effects of temperature and octanol-water partition coefficient (K-OW); the impacts of biofouling and hydrodynamics are reported separately. Overall, SPMDs responded proportionally to aqueous PAH concentrations; i.e., SPMD R-S values and SPMD-water concentration factors were independent of aqueous concentrations. Temperature effects (10, 18, and 26 degrees C) on R-S values appeared to be complex but were relatively small.