Analytical methodology and regulations for ochratoxin A.

Various methods exist to determine ochratoxin A. Currently they are often based on high performance liquid chromatography, but thin layer chromatography and enzyme-linked immunosorbent assay are also applied. Immunoaffinity column purification of extracts is an attractive approach to obtain clean extracts. Analytical quality assurance is essential to guarantee the integrity of analytical data and the use of reference materials plays an important role in this respect. (Proposed) regulations for ochratoxin A have been established in at least eight countries. The tolerance levels vary widely and the scientific basis for them appears to be weak.