Determination of Aflatoxins B1 and B2 in Powdered Milk Using Modified Liquid Chromatography Method

In this study، using a liquid-liquid microextraction method for pre-concentration trace amounts of aflatoxins، the amount of Aflatoxins B1 and B2 in powdered milk was determined. Determination of aflatoxins was done by using high-performance liquid chromatography coupled with fluorescent detector. Samples were extracted by immunoaffinity column (IAC) clean-up، and their eluents were used as dispersants of the subsequent DLLME، for further enrichment of aflatoxins. Various parameters (the type of elution solvent، the type and volume of extraction solvent and disperser solvent، extraction time and centrifugation time) that affect the efficiency of two steps were optimized. Under the optimum conditions، the calibrations for B1 and B2 were found to be linear in the range of 0. 03 -5. 0 and 0. 006-1. 0 ng ml-1 with 0. 98 and 0. 99 coefficient of estimation (R2)، respectively. The results showed that dispersive liquid–liquid microextraction combined with HPLC is a selective، simple، sensitive and effective analytical method for the pre-concentration and determination of ultra trace amounts of aflatoxins. The method is suggested for pre-concentration and determination of B1 and B2 aflatoxins in milk powder.