Analysis of Endocrine-Disrupting Compounds from Cheese Samples Using Pressurized Liquid Extraction Combined with Dispersive Liquid-Liquid Microextraction Followed by High-Performance Liquid Chromatography

Simultaneous extraction and preconcentration of five endocrine disrupting compounds including di-butyl phthalate, di-iso-nonyl phthalates, di-ethylhexyl phthalate, di-ethylhexyl adipate, and bisphenol A from cheese have been developed using pressurized liquid extraction combined with dispersive liquid-liquid extraction followed by high-performance liquid chromatography-diode array detector. In this method, initially, the analytes are extracted into a water-miscible extraction solvent (acetone) at high pressure (1000psi) and temperature (70 degrees C) in the presence of carbon tetrachloride as a modifier. After extraction, a volume of the organic phase is removed and dispersed into deionized water. The cloudy solution was centrifuged, and the sedimented phase is used in analysis. Efficient parameters were optimized using one-parameter-at-one-time strategy, and low limits of detection and quantification in the ranges of 0.82-3.1 and 2.8-10ngg(-1) were obtained, respectively. Relative standard deviations lower than 8% show an acceptable precision for the present method. The enrichment factors and extraction recoveries in the ranges of 259-319 and 78-96% were achieved, respectively. Lastly, some real samples were analyzed and di-butyl phthalate and di-ethylhexyl phthalate were found in them.