Comparative Evaluation of the Polar Organic Chemical Integrative Sampler (POCIS) in Two Types of Validation Systems

Polar organic chemical integrative sampler (POCIS) devices have been suggested for monitoring contaminant fluctuations in aquatic environments, resulting from chemical leak accidents. However, the response of the POCIS device in the emergency condition in natural water remains unclear. The response of the POCIS device to contaminant fluctuation was investigated using a simplified chamber test with tap water and a channel test with natural water in the present study. The fluctuation in the chamber and the channel replicated the condition of river water under a chemical leak scenario (maximum concentration: 1–10 μg L^–1, half-life: 1 d). The target chemicals were neonicotinoid pesticides (dinotefuran, clothianidin, thiamethoxam, imidacloprid, acetamiprid, and thiacloprid) and bisphenol A. The ratio of the POCIS measured value to the time-weighted average value of grab samplings (POCIS/TWA) for the channel test (temperature: 15 °C, flow velocity: 15 cm s^–1) ranged from 61% (clothianidin) to 133% (thiacloprid). The results indicated that the POCIS device could be effectively used as a monitoring device in an aquatic environment under the chemical leak scenario. In addition, the differences in the POCIS/TWA ratios obtained from the chamber test and the channel test were in the range of –50 to 50%, except for a few data points. Thus, the simplified chamber test could be used as a validation system to evaluate the POCIS device at a low cost.