Ochratoxin A is a mycotoxin produced by Penicillium and Aspergillus species. It is reported to be a genotoxic carcinogen. Transfer of ochratoxin A from feed to edible animal products, particularly pig kidney, has been demonstrated. Reliable analytical techniques for the determination of ochratoxin A are essential for establishment and enforcement of tolerance levels. A first intercomparison study of methods for the analysis of ochratoxin A in pig kidney highlighted problems in the areas of spiking and extraction of ochratoxin A from freeze dried pig kidney material. The inadequacy of analytical procedures as demonstrated by this first intercomparison study; together with the need for certified reference materials, led the European Union SMT programme to undertake a second intercomparison study for ochratoxin A in pig kidney.
The main aim of this second intercomparison study is to improve methods for the determination of ochratoxin A in pig kidney.
Particular objectives are:
- To address the reconstitution, spiking and extraction problems experienced in the first intercomparison study;
- To develop a method for ochratoxin A in pig kidney compatible with immunoaffinity column clean-up;
- To hold a second intercomparison study of methods for the determination of ochratoxin A, including the use of immunoaffinity columns.
The ultimate aim is to produce a certified reference material for analysis of ochratoxin A in pig kidney.
A reconstitution and spiking procedure has been developed with all participants will be required to follow. Investigations into extraction efficiency have indicated that use of a stronger acid in the extraction solvent (lower pH) may increase the amount of ochratoxin A extracted from the freeze dried pig kidney. Therefore, the second intercomparison study will compare methods using two different pH's for extraction.
Work in development of an immunoaffinity column method has demonstrated that the freeze dried pig kidney material is only homogeneous at a sample intake of 10 g (equivalent to 50 g reconstituted). All participants will be instructed to extract the entire 50 g of material following reconstitution according to the protocol provided.
Method adaptation will be carried out to address the problems of reconstitution, spiking and extraction. Specific procedures for reconstitution and spiking will be provided for participants in the second intercomparison study. An immunoaffinity column method will be developed which is compatible with the recommended reconstitution, spiking and extraction procedures. This method will be compared in the intercomparison study with traditional clean-up techniques and laboratories' own in-house immunoaffinitiy column methods.
Funding SchemeCSC - Cost-sharing contracts
G20 0SP Glasgow