Laboratory Intercomparison Study for the Analysis of Nonylphenol and Octylphenol in River Water

Abstract

In support of the implementation of the European Water Framework Directive (WFD) the European Commission (EC) Joint Research Centre (JRC) organized a laboratory and sampling intercomparison study for the chemical monitoring of polyaromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), and nonyl- and octylphenol (NP/OP), priority substances of the WFD, in river water. EU Member State laboratories were invited to analyse a standard solution with unknown concentration levels and a river water extract, as well as a real water sample from the River Po (N-Italy). For the standard solution and the river water extract good agreement was achieved for 5 laboratories. Triple quadrupole LC-MS-MS and GC-MS with or without derivatization showed to be well comparable methods for the analysis of NP and OP. Also fluorescence detection can be used to analyze NP/OP, but it is less specific. The results of the River Po water sample showed that some laboratories have problems in analyzing NP at concentration levels below 100 ng/L due to laboratory blank contamination. No plastic materials should be used during extraction and sample preparation.