scope:

This International Standard specifies a method for the determination of mono- to octa-polychlorinated naphthalenes (PCNs) in waters and waste waters (containing less than 2 g/l solid particulate material (SPM)) using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The congeners analysed by this method are listed in Table 1. The working range of the method is 20 pg/l to 8 ng/l. The method is optimized for PCNs, but may be modified to include other co-planar compounds such as polychlorinated dioxins and furans (PCDDs/PCDFs) and dioxin-like tetra- to hepta-chlorinated biphenyls (dlPCBs). This method may be used to determine PCNs in other matrices (e.g. biota, sediments, air), however additional clean-up steps and techniques may be required for samples with high organic loadings. Low resolution mass spectrometry (LRMS) and mass spectrometry/mass spectrometry (MS/MS) may be used and conditions are summarized in Annex A. Both LRMS and MS/MS may be less selective than HRMS and there is a possibility of bias due to interfering compounds if these techniques are used. The detection limits and quantification levels in this method are dependent on the level of interferences as well as instrumental limitations. The minimum levels (ML) in Table 2 are the levels at which the PCNs can typically be determined with no interferences present. This method is "performance based". The analyst is permitted to modify the method e.g. to overcome interferences, provided that all performance criteria in this method are met. The requirements for establishing method validation / equivalency are given in Clause 9.