Final Result of the European Research Project DIFFERENCE: New Alternative Methods for Dioxin Analysis

The European research project DIFFERENCE (“Dioxins in Food and Feed – Reference methods and New Certified Reference Materials”) was focussed on the development of alternative methods for the analysis of polychlorinated dibenzodioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) using comprehensive multi-dimensional gas chromatography (GC ́GC), gas chromatography combined with low resolution ion-trap mass spectrometry (GC-LRMS/MS), the CALUX bioassay and an Ah-PCR technique. GC combined with high resolution mass spectrometry (HRMS) was used as a reference method in all comparisons. Given the need for a regular monitoring of PCDD/Fs and PCBs in Europe, which was further enhanced by the implementation of the maximum residue levels (MRLs) for PCDD/Fs in food and animal feed per 1 July 20021,2, and the relatively high costs of GC-HRMS and the limited capacity for HRMS analyses in European laboratories, cheaper, faster, but reliable methods were badly needed. The method development part included a developmental phase, a validation phase and a standardisation phase. In addition to the method development, attention was also paid to alternative extraction and clean-up methods. Finally, the DIFFERENCE project also included a feasibility study on the preparation and certification of five reference materials. This part was included because at the moment no certified reference materials (CRMs) are available that cover all PCBs, PCDDs and PCDFs included in the European legislation.