The application of some star-shaped polymers (SSP) for transport and separation of metal cations in a liquid membrane system is described. The properties of core-functionalized CF-SSPs [-OP(O)(OH)(2) groups] with poly(oxyethylene) (POE) arms ended by methoxy groups were studied and compared to the properties of end-arm functionalized, EF-SSP, and non-ionic POE based SSPs. It was found that CF-SSPs enable the efficient and selective pertraction of Zn(II) and Cu(II) cations from a multi-cation feed solution containing Zn(II), Cu(II), Ca(II), Mg(II), K(I), and Na(I) nitrates. Under similar experimental conditions, the preferential transport of potassium cations was observed in the system with the liquid membrane containing dissolved nonionic SSP with POE-based arms. (C) 2010 Elsevier Ltd. All rights reserved.