Silica gel medium to detect molds that produce aflatoxin.

A chemically defined nutrient solution containing tartaric acid was made solid by mixing it with an alkaline silicate solution. Production of aflatoxin by asperfilli growing on the silica gel medium coincided with the presence of a blue fluorescent area surrounding colonies, as observed under long-wave ultraviolet light. Presence of aflatoxin in the medium was confirmed by drying the gels, extracting them with chloroform-methanol, and examining extracts for fluorescent materials by viewing them on thin-layer chromatograms under ultraviolet light.