THE EUROPEAN COMMISSION, Having regard to the Treaty on the Functioning of the European Union, Having regard to Regulation (EC) No 882/2004 of the European Parliament and of the Council of 29 April 2004 on official controls performed to ensure the verification of compliance with feed and food law, animal health and animal welfare rules (1), and in particular Article 11(4) thereof, Whereas: (1)Commission Regulation (EC) No 152/2009 (2) includes methods for the determination of the levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCBs) in feed. (2) Requirements should be set out concerning screening methods which identify the samples with significant levels of PCDD/Fs and dioxin-like PCBs (preferably selecting samples exceeding action thresholds and ensuring the selection of samples exceeding maximum levels) and which have a high throughput. With respect to the maximum levels, the false-compliant rate of those screening methods should be below 5 %. (3) Where the results achieved with the screening method exceed the cut-off value, the original sample should be analysed by means of a method capable of identifying and quantifying the PCDD/Fs and dioxin-like PCBs contained in the sample. Hereinafter such methods are referred to as ‘confirmatory methods’. Technical progress and developments have shown that the use of gas chromatography/tandem mass spectrometry (GC-MS/MS) should be allowed for use as a confirmatory method for checking compliance with the maximum level, in addition to gas chromatography/high resolution mass spectrometry (GC-HRMS)  .  .  .