Modeling of some calorimetric and spectropolarimetric titration data

Microcalorimetric and spectropolarimetric titrations were used to investiga te micellization of cationic surfactants and binding of netropsin to dodeca meric DNA duplex. For description of both processes, model functions contai ning linear and non-linear parameters were derived. Model analysis was base d on a weighted (multi)linear regression and a standard "Simplex" procedure . Close investigation of the interplay of adjustable parameters has shown t hat a proper choice of the model function can significantly reduce the corr elations between parameters. Values of physical properties (enthalpy change s, apparent equilibrium constants...) obtained from such curve modeling are in very good agreement with the corresponding values obtained by other met hods. Equations and the calculation procedure reported here could be easily generalized and used for the description of some other concentration depen dent properties in similar systems.