As more mycotoxins come under regulatory purview, new methods are needed to help food safety labs continue to operate efficiently. Comprehensive, multi-mycotoxin methods are an attractive alternative to separate methods for different analyte lists, but they can be difficult to develop due to the wide range of chemical characteristics among mycotoxin classes. In particular, the Alternaria toxins and ergot alkaloids create additional challenges for method developers. These emerging mycotoxin food contaminants are unique in that, when analyzed on a C18 column, high pH conditions must be used to obtain acceptable peak shape for the Alternaria toxins and adequate separation of the ergot alkaloid epimers. Use of high pH conditions is stressful for LC columns and not suitable for analyzing other classes of mycotoxins, so another approach is required for a truly comprehensive method. Analyzing compounds that have nonspecific adsorption (NSA) or nonspecific binding (NSB) to metal surfaces in LC columns has historically been a challenge. Poor peak shape and sensitivity are key indicators that polar, usually acidic compounds are interacting with the metal surfaces in the column, causing poor data quality.
Mycotoxins analysis can be challenging and often requires a great deal of column conditioning and equilibration to achieve acceptable peaks. This is due to the reactive nature of the compounds, which contain acidic, polar, or otherwise metal chelating groups. Inert column hardware, coupled with biphenyl stationary phase, helps simplify methods and improve the response and peak shape of these compounds. In this talk, I will describe how a simple sample preparation procedure, the unique selectivity of the biphenyl stationary phase run under acidic conditions, and inert column hardware technology combine to provide sensitive and efficient simultaneous analysis of Alternaria toxins, ergot alkaloid epimers, and other major mycotoxins.
