Salting-Out Induced Liquid-Liquid Microextraction: an Environmentally Friendly Approach to Preservative Determination in Food Samples

Abstract

The salting-out induced liquid-liquid microextraction technique was properly evaluated for preservative determination in processed food samples. In the best conditions, 0.5 g sample and 4.5 mL acetate buffer, at pH 4.2, were extracted with 1 mL acetonitrile, followed by agitation, addition of 2 g MgSO4, a new agitation step, and centrifugation. Afterwards, the extract was diluted with ultrapure water and analyzed by high-performance liquid chromatography with ultraviolet detection. Correlation coefficients above 0.99, LOQs between 0.03 and 0.07 mg kg−1, and recoveries between 80 and 103%, with RSD ≤ 11%, were achieved. When applied to preservative determination in food samples, the method under evaluation provided similar results to those obtained by a previously validated one. Finally, this method is a good alternative to determining preservatives in food samples, with the advantages of being greener, cheaper, and faster than the official ones.