Methods Sample extraction and dilution A 25 gram sample of our peanut butter was weighed out with 5 grams of NaCl and placed in a blender jar, then 125 mL of a 70% methanol:30% water mixture was added. The blender jar was covered and blended a high speed for 2 minutes. The blended extract was placed into a fluted filter paper and its filtrate was collected in a clean vessel. Approximately 15.0 mL of the filtered extract was poured into a clean vessel, diluted with 30 mL of distilled water and mixed well. 15 mL of the dilute extract was filtered through a microfiber glass filter into a glass syringe barrel.
Column Chromatography The 15 mL of filtered extract was passed through the Aflatest column at a rate of 1-2 drops/second, then the column was washed with 10 mL of distilled water at a rate of 1-2 drops/second, this step was repeated until air came through the column. The aflatest column was eluted with 1.0 mL HPLC grade methanol at a rate of 1-2 drops/second and the 1 mL of the sample eluate was collected into a glass cuvette. 1.0 mL of freshly made Aflatest Developer was added to the cuvette and the contents were mixed well. Using a calibrated fluorometer, fluorescence was measured the aflatoxin concentration was read after 60 seconds.