QuEChERS-HPLC method for aflatoxin detection of domestic and imported food in Jordan

Abstract

A method for the analysis of aflatoxins in food samples was developed. The preliminary work focused on optimizing sample pretreatment conditions such as the extraction solvent; the type and amount of drying agents; the extraction time; and the solvent-sample ratio. A 60:40 methanol/acetonitrile (%, v/v) extraction mixture provided recoveries in the range of 71.8–107.7% at spike levels of 1.5–50.0 ug/kg with relative standard deviations (RSDs) lower than 15%. The separation of the four aflatoxin compounds with high selectivity and sensitivity, and within reasonable retention times, was performed by a C18 250 mm x 4.6 mm x 5 um column (Nucleodur 250-5) at 45 0C. The developed QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) procedure, high performance liquid chromatography (HPLC) method was then compared with the fluorometric determination method. It was found that the fluorometric determination method had a poor precision and positive bias as compared to QuEChERS-HPLC method. A total of 669 domestic and imported food samples in Jordan were analyzed for their aflatoxins content. Peanut and peanut butter samples showed the highest incidence of contamination (10 contaminations) followed by pistachio nut samples (6 contaminations) and sesame seed samples (2 contaminations).