Immunoaffinity column for mycotoxins, its problems and solutions

抄録

The immunoaffnity column (IAC) methods using specific antibodies against mycotoxins have been developed. The use of IACs in the cleanup step of mycotoxin analysis provides a number of advantages over the conventional chemical methods, such as highly specific, simple and rapid, and saving toxic solvents. Recently, with the availability of commercial IACs for several mycotoxins, the IACs have become the powerful tools in the cleanup stage of mycotoxin analysis. However, there are some disadvantages of commercial IACs also. One of the major disadvantages is cost of IAC. To solve this problem, methods of regenerating IACs for reuse have been investigated. Other disadvantages are low and varied recoveries because of low mycotoxin affinity of IACs. In general, aflatoxins (AFs) are eluted with methanol from IAC. However, AFs are decomposed during evaporation of methanol eluate. To avoid this decomposition, acetonitrile elution from IAC was very effective. In the case of IAC for ochratoxin A (OTA), low recoveries result from low OTA affinity of antibody at pH condition other than neutral pH. By introducing 10 mM ammonium acetate buffer (pH 6.6) into the washing steps of IAC, high and stable recoveries of OTA could be achieved. Because of low toxin affinity of antibody against deoxynivalenol, only a small portion of sample solution can be applied onto IAC. To solve this problem, the combination of solid phase extraction column and IAC was effective.