Search for actual on-line methods of testing for mycotoxins, and you'll mostly find private labs that are looking for business. However, Aspergillus.org is kind enough to post a PDF of the 2006 article A review of rapid methods for the analysis of mycotoxins, first appearing in Mycopatholigia.
Another paper, Standardization of mycotoxin sampling procedures: an urgent necessity from the journal Food Control (2003) is courtesy of North Carolina State University.
An apparently unpublished paper from South Dakota State is available called Sampling and testing for aflatoxin in corn.
The lab Envirologix provides a few tips in Mycotoxin Testing.
Understanding Mycotoxin Testing and Interpretation is from EHS Today.
And finally, even though you can only access abstracts, this USDA research page lists many publications having to do with mycotoxins and their analysis.