Detection and Determination of some Migrated Chemicals from Plastic Containers into Different Drinks and Liquids Using Dispersive Liquid-liquid Microextraction Prior to Gas Chromatography

Migration of chemicals from plastic containers into drinks and liquids containing them, is supposed to be a hazardous phenomenon and results in many health problems. Sample preparation is of great importance due to trace amounts analysis of these compounds. In this research, dispersive liquid–liquid microextraction is applied for the extraction and preconcentration of the migrated compounds prior to their detection and determination by gas chromatography equipped with mass spectrometry or flame ionization detector. The method is on the basis of forming droplets of a water–immiscible organic solvent (extractant) into an aqueous phase by means of a disperser solvent. As a result, there would be a large contact area between the extractant and aqueous phase containing the analytes which boosts mass transfer. After centrifuging, the extractant is sedimented at the bottom of the aqueous phase and an aliquot of it is removed and injected into the separation system. Various experimental conditions which influence the extraction efficiency were optimized. Under the optimum conditions, the extraction recoveries were ranged from 52–63%. The relative standard deviations were ≤ 7.2% for intra– (n = 6) and inter–day (n = 4) precisions at a concentration of 20 µg L–1 of each analyte. The limits of detection were in the range of 0.18–0.38 µg L–1. Eventually the applicability of the proposed method for appraising the compounds migrated from the plastic containers was evaluated by analyzing the target compounds in different drinks and liquids stored in the plastic bottles.