Determination of Benzo (α) pyrene in infant formula milk using high performance liquid chromatography and dispersive liquid–liquid microextraction

Abstract

An analytical method for the extraction and quantification of benzo (α) pyrene (BaP) in infant formula milk has been established by dispersive liquid–liquid microextraction followed by high-performance liquid chromatography with fluorescence detector. In this study, BaP was first extracted from matrices of infant formula milk via acetonitrile and then DLLME was used for further purification and preconcentration of target analyte. Under the optimum extraction conditions, (150 µl of dichloromethane as extraction solvent, 3 mL acetonitrile as disperser and cleaner solvent and 1 mL volume sample) the accuracy of method was between 88.9 - 97%. The limits of detection and quantification were 0.12 and 0.35 ng/ml, respectively. There was a linear relation (R2=0.998) between chromatographic peak area and concentrations in the range of 0.5 to 15 ng/ml. The proposed method is applicable to quantification of BaP in infant formula milk with acceptable accuracy and precision.