The retention behavior of some anilides on unconventional TLC supports

Abstract

The TLC retention behavior of formanilide and 4-substituted acetanilides on starch and cellulose layers has been studied using aqueous mobile phases with methanol, acetonitrile, acetone, and 1-propanol as modifiers. R(Mw) values derived by linear extrapolation of the plot of R(M) against volume fraction of organic modifier to 100% water are not dependent on the nature of the organic modifier. Correlation was observed between R(Mw) values on starch and cellulose layers. Because R(M) values are related to the partitioning of the solute molecules in the given system, they can be regarded as a measure of a solute's hydrophobicity. We correlated R(Mw) values with the lipophilicity parameters, π and logP; the quadratic equation fit the data well. Multiple regression analyses was, furthermore, successfully applied with π, σ and HD as independent variables, suggesting that the electronic properties and hydrogen bonding of the substituent participate in the retention mechanism.