Comparative study of immunoaffinity column clean-up and modified quechers using HPLC-FLD with post-column derivatization for determination of aflatoxins in rice

A comparative study was carried out between two different sample extraction techniques including Immunoaffinity column (IAC) clean-up and modified QuEChERS method for determination of Aflatoxins (AFB1, AFB2, AFG1 & AFG2) in rice. These methods were validated using high performance liquid chromatography (HPLC) with post-column derivatization (i.e. bromine derivatization) in a KOBRA® cell using water: methanol (40:60 v/v), with addition of KBr and HNO3 as mobile phase, followed by fluorescence detection at excitation/emission wavelengths of 360/455 nm. The recoveries of Aflatoxins were in the range of 79.3-112.3% for both the sample extraction techniques, with relative standard deviation (% RSD) lower than 20%. The limits of detection and quantification were found to be 0.25µg/kg and 0.5µg/kg, respectively for both the methods. Both sample extraction techniques performed well, but the proposed modified QuEChERS approach was more time saving, cost-effective and easy for analysis of aflatoxins, while achieving excellent sensitivity.