Application of pressurized liquid extraction in the analysis of aflatoxins B1, B2, G1 and G2 in nuts

Aflatoxins (AFs) B-1, B-2, G(1) and G(2) were extracted from nuts by using pressurized liquid extraction (PLE) and the PLE extracts were analyzed using HPLC with fluorescence detection using photochemical post-column derivatization without further cleanup procedures. Several extraction parameters such as temperature (25, 40, 60 and 80 degrees C), pressure (500, 1.000, 1500 and 2000 psi), solvent extraction mixture (acetone, acetonitrile, ethyl acetate and methanol), number of cycles (I and 2), use of dispersing agents and cell size (5 and 11 mL) were investigated for their effects on the extraction performance. The results showed 60 degrees C, 1500 psi, acetonitrile, one cycle and a cell size of 5 mL as most favorable PLE operating conditions. The proposed analytical method provides LODs below the maximum levels established by European Union regulations and the recoveries of the four AFs were between 77 and 93% at spiking levels of 4, 2 and 0.5 mu g/kg for AFB(1) and AFG(1) and 1, 0.5 and 0.13 mu g/kg for AFB(2) and AFG(2). Validation was carried out using certified reference materials. PLE has been applied for the first time to the analysis of AFs in nuts and offers the possibility for fast simple and accurate quantitative determination of studied mycotoxins.