ANNEX VMETHODS OF ANALYSIS TO CONTROL UNDESIRABLE SUBSTANCES IN FEED
F1B. DETERMINATION OF THE LEVELS OF DIOXINS (PCDD/PCDF) AND PCBs
CHAPTER II Sample preparation and requirements for methods of analysis used in offical control of the levels of dioxins (PCDD/Fs) and dioxin-like PCBs in feed
7. Specific requirements for bioanalytical methods
7.1. Evaluation of the test response
7.1.5. Control of recoveries for clean-up
The loss of compounds during the clean-up shall be checked during validation. A blank sample spiked with a mixture of the different congeners shall be submitted to clean-up (at least n = 3) and the recovery and variability checked by a confirmatory method. The recovery shall be within 60 % to 120 % especially for congeners contributing more than 10 % to the TEQ-level in various mixtures.