Partition Studies on Aqueous Two-Phase System using Sodium Dodecyl Sulphate and Ammonium Salts for Extraction of Dyes

An aqueous two-phase system consisting of sodium dodecyl sulphate (SIDS), an anionic surfactant, and NH4NO3 / (NH4)(2)SO4 as salting out agent has been used for the extraction of ionic dyes. Transparent aqueous two-phase system is obtained when solution containing surfactant concentration (3 mL - 0.2 M SDS), NH4NO3 / (NH4)(2)SO4 salt (0.8 g) and 1 mL of dye sample solution are mixed. The two-phase system thus obtained is of 3.0 +/- 0.2 mL of upper phase and 1.6 +/- 0.2 mL of lower phase. The partition behavior of dyes has been studied with various salts and results showed that among the studied systems, NH4NO3 - SDS and (NH4)(2)SO4 - SDS systems were found suitable for dye extraction. The effect of neutral, acidic and basic media on the extraction process has been investigated. Extraction of dye contents has been followed by UV-Visible spectrophotometeric technique. Results showed that dyes (both anionic and cationic) were efficiently extracted into the upper phase.