Talanta 89 (2012) 322–334 Contents lists available at SciVerse ScienceDirect Talanta jo u r n al hom epage: www.elsevier.com/locate/talanta Validation of a method for the analysis of 77 priority persistent organic pollutants in river water by stir bar sorptive extraction in compliance with the European Water Framework Directive F.J. Camino-Sánchez b , A. Zafra-Gómez a,∗ , S. Cantarero-Malagón a , J.L. Vílchez a a Research Group of Analytical Chemistry and Life Sciences, Department of Analytical Chemistry, Campus of Fuentenueva, University of Granada, E-18071 Granada, Spain b Laboratories Cavendish S.L.U. TM Research Department, E-18220 Granada, Spain a r t i c l e i n f o Article history: Received 30 September 2011 Received in revised form 25 November 2011 Accepted 4 December 2011 Available online 19 December 2011 Keywords: Stir bar sorptive extraction GC–MS/MS River water Persistent pollutants Priority substances European Water Framework Directive Water analysis a b s t r a c t A multi-residue method for the analysis of semi-volatile organic pollutants in inland groundwater (river water) at ultra-trace levels in compliance with the European Water Framework Directive (WFD) has been developed and validated by stir bar sorptive extraction (SBSE) and thermal desorption coupled with gas chromatography–triple quadrupole mass spectrometry (SBSE-TD–GC–MS/MS(QqQ)). The method includes various families of compounds included in the WFD and other compounds listed as persistent organic pollutants that are banned in the Stockholm Convention of Persistent Organic Pollutants, such as polychlorinated biphenyls, polycyclic aromatics hydrocarbons, and other pesticides not included in the WFD. The method also can be applied for compliance with regional environmental laws. Extraction conditions were optimised in order to analyse simultaneously analytes with very different polarities and octanol–water partition coefficients, which is an important parameter in the optimisation of a SBSE method. The quantification limits (LOQs) obtained ranged from 0.14 to 10 ng L -1 , lower that others pre- sented in previous publications, and complies with the requirement for analytical methods to be used in the analysis of the compounds included in the WFD. Several quality parameters as linearity, trueness and precision were studied with good results, and also uncertainty was estimated. The WFD requires that the level of uncertainty must be lower than 50%, and this requirement was met for all compounds. Precision (in terms of RSD) was lower than 30%, recoveries ranged between 74 and 111%, and determina- tion coefficients were higher than 0.990 for all analytes. Different factors that affect the SBSE procedure were optimised. GC–MS/MS parameters have also been revised. The accuracy of the method was tested participating in a proficiency testing scheme for each group of analytes. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Water is the mainstay of the environment and its degradation has serious consequences: protecting the water means protecting the ecosystems of which it forms an inseparable part. Waters are subject to great risk, primarily due to pollution and the growing need for quality water. These risks compromise their sustainable long-term availability so measures are needed to reverse negative trends, enable the protection of water, prevent deterioration and restore those waters that are in poor condition. The European Union is going to great lengths to improve water quality, one sign of which is the European Water Framework Directive (WFD) adopted in the year 2000 [1]. ∗ Corresponding author. Tel.: +34 958 243326; fax: +34 958 243328. E-mail address: azafra@ugr.es (A. Zafra-Gómez). The purpose of this directive is to establish a protective frame- work for all inland surface waters, transitional waters, coastal waters, and groundwater in order to prevent deterioration and pro- mote their sustainable use through protection in the medium and long term. This target must be achieved in each hydrographic basin by the year 2015. Therefore, by 2015 all EU waters should be in good condition. Decision No. 2455/2001/EC approved the list of pri- ority substances that should be tested [2], which was followed by Directive 2008/105/EC, which established environmental quality standards (EQS) in the field of the WFD [3]. The latter establishes the maximum allowable concentrations of priority substances in different types of waters. The WFD is a highly complex legal and technical document and the quantification limits required are extremely low. The WFD states that the methods used for the control of substances must comply with a LOQ equal to or less than 30% of the annual average environmental quality standard (AA-EQS), which are in the pg L -1 range of in some cases. The listed substances are classified into 0039-9140/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.talanta.2011.12.037