Partial molal volumes of transfer of some amino acids from water to aqueous 1,4-dioxane solutions at 298.15 K

Abstract

Apparent molal volumes of glycine , DL-α-alanine , <img src='http://www.niscair.res.in/jinfo/small.gif' border=0>-valine, <img src='http://www.niscair.res.in/jinfo/small.gif' border=0>-leucine and <img src='http://www.niscair.res.in/jinfo/small.gif' border=0>- phenylalanine in water and in 2.5, 5, 10, 20, 25% aqueous solutions of 1,4-dioxane have been obtained from densities of their solutions at 298.15 K measured by using precise vibrating tube digital densitymeter. The estimated partial molal volumes (<img src='http://www.niscair.res.in/jinfo/v.gif' border=0>₂⁰) at infinite dilution have been

used to obtain corresponding transfer volumes (<img src='http://www.niscair.res.in/jinfo/v.gif' border=0>^o_{2, <i>tr</i>}) from water to different 1,4-dioxane-water mixtures which have been found to be positive for glycine, and both positive and negative for the remaining amino acids over the 1,4-dioxane concentration range studied. The data have been interpreted in terms of solute-cosolute interactions. Concentration dependent behaviour of 1,4-dioxane in aqueous solutions have also been taken into account while interpreting the <img src='http://www.niscair.res.in/jinfo/v.gif' border=0>^o_{2, <i>tr</i>} values of amino acids.