SFE EXTRACTION OF AFLATOXINS (B-1, B-2, G(1), AND G(2)) FROM CORN ANDANALYSIS BY HPLC

A supercritical-fluid extraction (SFE) method has been developed that extracts aflatoxins B-1, B-2, G(1), and G(2) from spiked corn using mo dified supercritical carbon dioxide. Methanol is added to the SFE extr action cell containing the corn layered between Hydromatrix (a dispers ing material) which helps to prevent the clogging of the frits and red uces the effect of moisture on the extraction. The corn is held in sta tic extraction at 65 degrees C and 51.7 MPa for 15 min followed by a d ynamic extraction with 20 mL of liquid carbon dioxide. The sample is d epressurized and modifier re-added with a 10-min static extraction at 51.7 MPa followed by a dynamic extraction with 20 mt of liquid carbon dioxide. The SFE extract is collected in 10 mL of chloroform and furth er cleaned up with a Florisil Sep-Pak. The aflatoxins were analyzed by HPLC using fluorescence detection after post-column derivatization wi th iodine. Recoveries of the aflatoxins B-1, B-2, G(1), and G(2) over a range of 3 to 11 ng g(-1) averaged 77.3, 82.9, 75.4, and 80.3%, resp ectively.