Overview of passive Chemcatcher sampling with SPE pretreatment suitable for the analysis of NPEOs and NPs

The European Union Water Framework Directive (WFD; 2000/60/EC) is an important piece of environmental legislation that protects rivers, lakes, coastal waters and groundwaters (EC 2000 ). The implementation of the WFD requires the establishment and use of novel and low-cost monitoring programmes, and several methods, e.g. passive sampling, have been developed to make the sampling process more representative compared to spot sampling. This review considers passive sampling methods focusing mainly on a passive sampler named Chemcatcher®, which has been used for monitoring several harmful compounds in aquatic environments. Also, the sample treatment and analysis of nonylphenol ethoxylates (NPEOs) and nonylphenol (NPs) from water using solid phase extraction (SPE) is briefly summarized. The procedure of Chemcatcher passive sampling is quite similar to that of the SPE extraction since it concentrates the studied compounds from water as well. After sampling, the accumulated substances are extracted from the receiving phase of the sampler. The concentrations of NPEOs and NPs are currently monitored by taking conventional spot samples; SPE can be successfully used as a pretreatment procedure. Chemcatcher® passive sampling technique is a simple and useful monitoring tool and can be applied to new chemicals, such as NPEOs and NPs in aquatic environments.