Development of simultaneous derivatization and air–assisted liquid–liquid microextraction for extraction and preconcentration of parabens in cosmetic, hygiene and personal care product

Parabens (a group of alkyl esters of p–hydroxybenzoic acid) are widely employed as preservatives in cosmetic and personal care products due to their broad spectrum of antimicrobial activity and ideal physicochemical properties [1]. However, the extensive inclusion of these chemicals in everyday consumption products has raised concerns about their potential long-term effects on human health and on wildlife [2]. So, trace analysis of them is important to protect human health.In this study, an air–assisted liquid–liquid microextraction technique has been developed for the simultaneous derivatization, extraction, and determination of some parabens (methyl–, ethyl–, and propylparaben) in different samples before their determination by gas chromatography-flame ionization detection. In this work, pivaloyl chloride as a derivatization reagent was used in efficiently and rapidly derivatization of the selected parabens to improve their chromatographic behavior. For this purpose, sample solution is transferred into a glass test tube and a mixture of pivaloyl chloride and toluene (as an extraction solvent) was added into the solution. After performing the predetermined numbers of aspiration/dispersion cycles (six times), a turbid solution was obtained. Then, the mixture was centrifuged for 5 min at 5000 rpm. Then a home-made device with narrow section was placed into the test tube to collect the extraction solvent. Finally, 1 µL of the extraction solvent was removed by a microsyringe and injected into the separation system. Under the optimum extraction conditions, limits of detection and quantification for the target analytes were obtained at the ranges of 33–50 and 110–169 ng mL−1, respectively. The Enrichment and enhancement factors are at the ranges of 360–430 and 470–650, respectively. The calibration graphs were linear with good coefficients of determination (r2 0.994). Finally, the target parabens were determined in cosmetic and hygiene samples and personal care products by the proposed method.