Mm. Hossain et Ra. Stanley, SELECTIVE TRANSPORT OF A PEPTIDE FROM ITS MIXTURE WITH AN AMINO-ACID USING A SUPPORTED LIQUID MEMBRANE PROCESS, Separation science and technology, 30(20), 1995, pp. 3801-3819
Some experimental results on the separation of a peptide from a mixtur
e of peptide and amino acid through a continuous supported liquid memb
rane process are described. As a model system a mixture of tryptophan
(Trp, an amino acid) and tryptophan-leucine (Trp-Leu, a dipeptide) was
chosen. The liquid membrane contained an anionic surfactant, sodium d
i-2-ethylhexyl sulfosuccinate (Aerosol OT/AOT), as a carrier dissolved
in oleyl alcohol, as an organic solvent, supported on a commercial gr
ade support (Celgard 2500). The liquid-liquid extraction experiments w
ere carried out to study the influence of feed pH, feed and strip flow
rates, and feed and carrier concentrations on the selective transport
of Trp-Leu from its mixture with Trp. At pH 4-5 the transport rate of
Trp-Leu was significantly higher than that of Trp. The increase in fl
ow rate up to a value of 40 mL/h did not effect the selective removal
of Trp-Leu. The flux rate increased with an increase of the carrier co
ncentration up to 20% AOT, but the selectivity for Trp-Leu was highest
at 10% AOT. An increase of Trp concentration up to 10-fold had little
effect on the flux rate of Trp-Leu. The stability of SLM system in co
ntinuous removal of Trp-Leu from a single component system and from a
binary mixture with Trp was studied. The effect of a competitive compo
nent did not alter significantly the flux rate and long-time performan
ce in continuous operation. A procedure for regenerating SLM was exami
ned, and the regenerated SLM performed as good as the freshly prepared
one.