The mixture was kept at 40 C for 10 min, evaporated to near-dryness and diluted in 1 mL ofmethanol:water (50:50, v/v). Final extracts were filtered through a 0.45 mm PTFEmembrane prior to injection into HPLC column. Bean samples were extracted exactly by the same method
described for corn samples, except that 20 mL were eluted through the immunoaffinity column.