Cork-based passive samplers for monitoring triclosan in water samples

Abstract

Novel passive samplers based on cork as a sorbent phase were implemented for the sampling and preconcentration of triclosan in water. Two sampler configurations were developed: The larger sampler (cork passive sampler, CPS) involved a Teflon casing to protect a circular laminar cork phase with a diameter of 4.5 cm, which was covered by polyethersulfone membranes. In the smaller sampler (miniaturized cork sampler, MCS), a circular piece of cork with a diameter of 0.8 cm was directly exposed in the water samples.The sampling rates were calculated through static kinetic calibration tests in the laboratory, and linearity was observed in the kinetic part of the absorption (or depletion) curve. The sampling rates were 0.47 L d −1 and 3.9 × 10−4 min−1 for CPS and MCS, respectively. The difference in these values was attributable to the substantial variation in the surface area of the exposed sorbent phase (approximately 25 times). Compared with that associated with existing passive devices, the use of cork in passive sampling devices yielded larger values of sampling rates in several cases. The samplers presented isotropy, which suggested uniform sorption and desorption capacities.The samplers were tested in the field to quantify the amount of triclosan in wastewater and river water at points near a wastewater treatment plant. The triclosan content was 19–390 and 7–271 ng L-1 for wastewater and river water, respectively. The persistence and increase in the triclosan level indicates that its use continues to be pervasive without any regulation. The proposed samplers based on cork represent an ecofriendly, efficient, low-cost and easily accessible alternative to monitor triclosan over long periods.

Keywords

• Passive sampling
• Cork
• Triclosan
• Natural sorbent phase