Binary Diffusion Coefficients of Arachidonic Acid Ethyl Esthers, <i>cis</i>-5,8,11,14,17-Eicosapentaenoic Acid Ethyl Esthers, and cis-4,7,10,13,16,19-Docosahexanenoic Acid Ethyl Esthers in Supercritical Carbon Dioxide

Abstract

The binary diffusion coefficients of arachidonic acid ethyl esthers (AA-EE), cis-5,8,11,14,17-eicosapentaenoic acid ethyl esters (EPA-EE), and cis-4,7,10,13,16,19-docosahexaenoic acid ethyl esthers (DHA-EE) in supercritical carbon dioxide were measured at temperatures from 308.15 K to 338.15 K and pressures from 8.42 MPa to 29.95 MPa by the Taylor−Aris capillary peak broadening method. The obtained diffusion coefficients are in the range of (5.54 × 10-5) cm2·s-1 to (13.8 × 10-5) cm2·s-1 with small differences between AA-EE, EPA-EE, and DHA-EE. The measured D12 values were fitted with absolute average deviations of less than 2 % by three predictive models: Scheibel, Catchpole−King, and He−Yu−Su.