Cloud Point Extraction of Bisphenol A from Water Utilizing Cationic Surfactant Aliquat 336

Cloud point extraction(CPE) Utilizing a cationic surfactant, tricaprylmethylammonium chloride (Aliquat 336), was carried out to separate and concentrate bisphenol A( BPA) from aqueous media. Cloud point phase separation of Aliquat 336 at room temperature (about 25 degrees C) was induced by the addition of Na2SO4. The parameters affecting extraction efficiency, such as concentrations of Aliquat-336 and Na2SO4, pH, and equilibration time were evaluated. The results showed that the extraction efficiency was practically constant in the studied range of Aliquat 336, co-solvent (methanol), pH an(] dissolved organic matters. At the operational CPE conditions, distribution constant, K-D, of the distribution of BPA between the surfactant-rich and aqueous phases of the CPE system was estimated to be 10(4). Coupled to liquid chromatography with UV detection, the CPE method offered a detection limit of 0.34 mu g/L in distilled water and recovery of BPA ranged front 90% to 108.6% with I sample volume of 50 nil, in three matrices studied. The high extraction efficiency might be due to combination of ion-pair, hydrophobic effects and cation-pi interaction, based on the micelles' size distribution and zeta potential analysis.