title: The permeability of hydrophobic membranes to 22Na salts and 14CO2 in low dielectric media.
abstract: The one-way fluxes of 14CO2 and a series of 22Na (Cl, Br, HCO3, ClO4, I) salts across n-hexadecane-impregnated solid-support liquid membranes have been measured in water and low dielectric media (50-90 vol% dioxane/water). One-way fluxes for 14CO2 (J14CO2) were 0.84 and 1.03 x 10(-9) mol cm-2 s-1 in 75% dioxane (aq.) and water, respectively, across both impregnated cellulose and teflon membranes. 22Na fluxes across impregnated cellulose membranes in 75% dioxane (aq.) ranged from 1.8 to 11.4 x 10(-10) mol cm-2 s-1 and had the order NaCl less than NaBr less than NaHCO3 less than NaClO4 less than Nal. 22Na fluxes across impregnated teflon membranes were slightly smaller, 1.5-7.1 x 10(-10) mol cm-2 s-1, but had the same order for the anions tested. No measurable 22Na fluxes were observed in aqueous media. For NaI and NaClO4 there was a 3-6-fold enhancement of fluxes in 90% dioxane (aq.) compared to 75% dioxane (aq.). The corresponding enhancement for fluxes of NaHCO3, NaBr and NaCl was 1.5-fold. The results are discussed in terms of ion-paired salt transport in low dielectric media.
authors.affiliation: Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville 32610.
authors.forename: C W
authors.initials: CW
authors.lastname: Conroy
authors.forename: T H
authors.initials: TH
authors.lastname: Maren
mesh_terms: D000473:Alkanes; D001639:Bicarbonates; D002245:Carbon Dioxide; D002250:Carbon Radioisotopes; D002463:Cell Membrane Permeability; D004553:Electric Conductivity; D007700:Kinetics; D008567:Membranes, Artificial; D008962:Models, Theoretical; D012492:Salts; D012964:Sodium; D017693:Sodium Bicarbonate; D012979:Sodium Radioisotopes
chemical_list: D000473:Alkanes; D001639:Bicarbonates; D002250:Carbon Radioisotopes; D008567:Membranes, Artificial; D012492:Salts; D012979:Sodium Radioisotopes; D002245:Carbon Dioxide; D017693:Sodium Bicarbonate; D012964:Sodium; C007932:n-hexadecane