Passive sampling in monitoring of nonylphenol ethoxylates and nonylphenol in aquatic environments

Abstract

The present practices for determining the concentration levels of various pollutants are in many respects insufficient and for this reason, there is an urgent need especially to develop more cost-effective sampling methods. In this study, a novel passive sampling tool (the Chemcatcher®) for monitoring nonylphenol ethoxylates (NPEOs) and nonylphenol (NP) in aqueous media was tested. These environmentally harmful substances have been widely used in different household and industrial applications and they affect aquatic ecosystems, for example, by acting as endocrine disrupting compounds. The highest accumulation of NPEOs and NP in laboratory-scale tests was obtained when using an SDB-XC (standard styrene-divinyl benzene) Empore disk as a receiving phase (adsorbent) of the passive sampler. The accumulation of these compounds was then field tested by this technique for two or four weeks at two sampling sites which had received effluents from e.g. the pulp and paper industry for decades. In addition, the samplers were exposed in seawater conditions, although in these cases the results were, mainly due to a too long sampling time period, only approximate. In all cases, NPEOs and NP were analysed by high-performance liquid chromatography coupled with an electrospray ionisation mass spectrometry (HPLC/ESI-MS). These compounds were also separated from water samples using solid phase extraction (SPE) pretreatment which showed to be a useful tool for this purpose. It could be concluded that passive sampling with Chemcatcher® offers an effective technique suitable for monitoring NPEOs and NP in watercourses. However, more accurate data (e.g., obtained by LC/MSMS) on various contaminants are still needed for further method development.