Influence of complexation by metal cations on solvophobic retention of crown compounds in reverse-phase high-performance liquid chromatography

The retention of crown compounds in reverse-phase HPLC is determined by their ability to bind to cations present in the eluent. The dependence of the retention of crown compounds on concentration of the binding cation has a break. This enables the stability constant of the crown-compound-cation complex to be calculated. The retention of the antitumor antibiotic actinomycin D in 75% MeOH is demonstrated to depend on [Na⁺] and not on [K⁺] for concentrations of the latter from 10^–6 to 10^–1 M.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2265–2269, October, 1991.