Aqueous Biphasic Systems as a Suitable Route to Remove and Concentrate Parabens from Aqueous Media

Abstract

Parabens are substances used as preservatives in cosmetics and food products, the extensive use of which results in their accumulation in the environment. In this work, aqueous biphasic systems (ABSs) were evaluated as a tool to separate and concentrate parabens (methyl-, ethyl-, propyl-, and butylparaben) from aqueous media. The liquid−liquid equilibrium experimental data of different ABSs composed of polymers [poly(ethylene)glycol, M w : 6000, 2000, and 400 g•mol −1 and poly(propylene)glycol (PPG), M w : 400 g•mol −1 ], salt [(NH 4 ) 2 SO 4 ], and water were obtained. The proposed systems were effective to partition the parabens to the polymer phase (extraction efficiencies up to 99.9%). Because of the higher hydrophobicity, PPG 400 promoted a higher paraben concentration with a lower polymer amount. Additionally, the evaluation of the phase volume ratio through the alpha parameter adjustment allows tuning the ABSs with the desired application, for example, concentration as a potential step in detecting these compounds.