Rapid calibration approaches for polytetrafluoroethylene-based polar organic chemical integrative sampler under
Kazushi Noro1, Miyu Moriya2, Yoshinori Yabuki3
1Center for Health and Environmental Risk Research, National Institute for Environmental Studies, Onogawa 16-2, Tsukuba, 305-8506, Ibaraki, Japan.
Abstract:
Polar organic chemical integrative samplers (POCIS) are widely used for monitoring time-weighted average concentrations of hydrophilic contaminants in aquatic environments; however, their application is often constrained by the time- and labor-intensive calibration required to determine sampling rates (Rs). In this study, we evaluated two rapid calibration approaches for POCIS under standardized laboratory hydrodynamic conditions: an accelerated short-term static experiment (Rs1) and a mass-transfer-based modeling approach (Rs2), and compared their performance with conventional long-term calibration. Using polyethersulfone (PES) and polytetrafluoroethylene-membrane (PTFE) POCIS devices, Rs values were determined for 73 pesticides spanning a wide range of octanol-water partition coefficients (log Kow -0.66 to 5.2). For PTFE-POCIS, Bland-Altman analysis revealed that Rs2 exhibited the highest agreement with experimentally determined Rs values, showing near-zero bias (-0.0056), the lowest root mean square error (0.101), and narrow limits of agreement without evidence of proportional bias. Rs1 showed slightly reduced accuracy but maintained acceptable agreement, whereas literature-based empirical estimation methods exhibited larger proportional bias and systematic overestimation. Considering both calibration efficiency and relative cost, the Rs1 method was identified as the most practical accelerated calibration approach. In contrast, neither rapid approach successfully reproduced Rs values for PES-POCIS, likely because sorption-driven lag processes within the membrane contributed substantially to uptake behavior under the tested conditions. These results indicate that the applicability of rapid calibration approaches depends strongly on membrane properties and uptake behavior under controlled laboratory conditions. The proposed approaches may provide practical strategies for rapid calibration of PTFE-based POCIS devices and support efficient environmental monitoring of hydrophilic contaminants.
