Determination of dioxins (PCDDs/PCDFs) and PCBs in food and feed using the DR CALUX® bioassay:: Results of an international validation study

Maximum levels for dioxins in food and feedstuffs have been recently established by the European Commission through two regulations. Dioxin-monitoring programmes of food and feedstuffs will therefore be undertaken by the European Member States to implement these regulations, which would be facilitated by fast and low-cost screening methods. Commission Directives 2002/70/EC and 2002/69/EC describe specific characteristics for such screening methods. In the present study, the performance characteristics of the DR CALUX((R)) method from BioDetection Systems were established in a validation study with 14 participants. The study was based on two materials ( fish oil and feed), each containing four different levels of dioxins and dioxin-like PCBs around the current limits. The results demonstrate that the test is very promising but that in particular the clean-up procedure was a source of variation and requires further optimization and standardization. In addition the quantification is improved by the use of control samples to correct for background contamination, recovery and differences between the TEF values and REP (relative potency) factors in the test.