Development and characterization of a new polyampholyte-surfactant complex applied to the solid phase extraction of...

This paper presents a material that has both hydrophilic and hydrophobic domains, obtained by combination of a polyampholyte with a surfactant. This material was fully characterized by different spectroscopic techniques and microscopy. Bisphenol-A (BPA) was chosen as a model molecule to study the interaction with compounds of intermediate polarity. We explored the kinetics and equilibrium of BPA on the surface of the polyampholyte-surfactant complex and found a significantly high loading capacity (2.02 mmol g(-1)) and complete binding from solutions at concentration levels below 100 micromol L(-1). The complex was encapsulated in agarose gel to be used as solid phase for extraction of BPA from food simulants in contact with polycarbonate bottles under different treatments. Bisphenol was preconcentrated, extracted and analysed by liquid chromatography with an amperometric detector. The instrumental detection limit of the technique was 10 microg L(-1), which was lowered to 0.14 microg L(-1) by the preconcentration step. The BPA released from baby bottles was 2.1 ng cm(-2) (sigma(n-1): 0.1) in the first use with distilled water.