Temperature dependence of the Kovats retention indices for alkyl 1,3-diketones on a DB-5 capillary column

Abstract

A series of alkyl 1,3-diketones were used to study the temperature dependence of the Kovats retention indices in the temperature range 130–190 ºC (403–463 K). The temperature dependence is described by the empirical equation I = B + B/T + ClnT. On the basis of this equation, the activation enthalpy, DH#, and the chemical potential of the partitioning of one methylene group between the two phases of the chromatographic system, Dmp(CH2), were calculated. Also, the Kovats retention indices – boiling point correlations (linear and reciprocal) for alkyl 1,3-diketones were studied and Dmp(CH2) was calculated.

Keywords

• retention indices
• alkyl 1
• 3-diketones
• temperature dependence