Edible oil-based switchable-hydrophilicity solvent liquid-liquid microextraction coupled with HPLC-DAD for determination of parabens in food and pharmaceutical products

The use of green sustainable solvents and miniaturized sample preparation methods are among the drivers for green analytical chemistry. Edible oils have been shown recently to possess switchable-hydrophilicity behaviour that makes them suitable candidates for extraction and preconcentration of analytes. This study aims to investigate their applicability for the preconcentration of parabens in food and pharmaceutical samples prior to their determination by HPLC-DAD. At optimum conditions, linear calibration graphs were obtained with coefficient of determination (R2) between 0.9950 and 0.9993. The limit of detection (LOD) ranged between 0.2 and 0.5 mu g/mL (0.2-0.4 mu g/ g). The precision of the method based on percentage relative standard deviations (%RSD) were below 6.8%, with percentage relative recoveries (%RR) between 90.4% and 106.0%. Enrichment factor was achieved between 6.6 and 41.5 folds which improved the sensitivity of the method to enable detection limits within the recommended limits set by regulatory bodies for parabens in the investigated samples.