This document is applicable to the determination of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), (together termed ‘dioxins’ (PCDD/Fs)) and dioxin-like PCBs and non-dioxin-like PCBs (dl-PCBs and ndl-PCBs) in animal feeding stuffs. Collaborative studies have been carried out. The method is suitable for the determination of dioxins, dl-PCBs and ndl-PCBs at the appropriate MRL in compound feed and ingredients e.g. oil, mineral clay. The method is applicable to samples containing trace level amounts of one or more dioxins, dioxin-like PCBs and non-dioxin-likePCBs. The limit of quantification (LOQ) is - 0,05 pg/g (OCDD/F = 0,1 pg/g) for the relevant individual congeners of dioxins/furans, - 0,05 pg/g for non-ortho PCBs, - 10 pg/g for mono-ortho PCBs, and - 100 pg/g for non-dioxin-like-PCBs. For determination of dioxins and dioxin-like PCBs, the procedure can be used as confirmatory method as defined by Commission Regulation (EC) No 152/2009 for dioxins and dl-PCB in feed [1]. Confirmatory methods as described in this standard are high-resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) methods. If only the analysis of non-dioxin-like PCBs is required, a GC-LRMS method can be used (e.g. EN 15741 [2]) provided that appropriate analytical performance criteria are met in the relevant range for the matrix of interest. This document is split into four modules. Each module describes a part of the whole procedure (see Figure 1 and Figure 2) to be followed: a) Module A: Description of standards which might be used; b) Module B: Description of extraction procedures; c) Module C: Description of clean-up procedures; d) Module D: GC/HRMS determination. Each module describes a part of the whole method as well as, when applicable, alternatives which should be equivalent. Each module has to be regarded as an example. Combining modules and/or alternatives gives a highly flexible, "performance based" procedure. It is permitted to modify the method if all performance criteria laid down in Commission Regulation (EC) No 152/2009 [1] are met. Any deviation of the described method, combination of modules needs to be recorded as part of the QA/QC procedures of accredited laboratories and should be available on request. Figure 1 - Flow scheme for the determination of dioxins, dl-PCBs and non-dioxin-like-PCBs in feed Figure 2 - Flow scheme for the determination of dioxins, dl-PCBs and non-dioxin-like-PCBs in oil and fat