Development of a Passive Sampler for Monitoring of Carbamate and s-Triazine Pesticides in Surface Waters

A new sampling system has been developed for the measurement of time-averaged concentrations (TWA) and diffusion coefficients of organic micropollutants in aquatic environments. The system is based on the diffusion of targeted organic compounds through a rate-limiting membrane and the subsequent accumulation of these species in a bound, hydrophobic solid-phase material. Two separate prototype systems are described. One is suitable for the sampling of carbamates such as carbaryl, carbofuran, 3-hydroxycarbofuran, baygon, propham, clorpropham, and the other one for s-triazines such as atrazine, prometryn, propazine, simazine, terbuthylazine, terbutryn, metribuzin, cyanazine, and metamitron pesticides. The systems use solid-phase material (47-mm C-18 Empore disk) as the receiving phase but are fitted with rate-limiting membranes of either polysulfone or polycarbonate. For the two designs investigated, the cumulative uptake of all target analytes was considered over exposure periods of 7 days. The determined sampling rates ranged from 0.1323 to 0.0465 L day(-1) with both membranes. The best system was the one with the polysulfone membrane allowing a better cumulative uptake.