Role of solvent properties and composition on the solid-liquid equilibrium of trifloxystrobin and thermodynamic analysis

This paper is to critically analyze the effects of solvent properties and composition on the solubility of trifloxystrobin. The solubility of trifloxystrobin in eight mono-solvents and two binary solvents was determined at temperatures ranging from 283.15 K to 318.15 K. Among the selected mono-solvents, the solubility of trifloxystrobin in alcohols was greater than that in alkanes and obeyed the following order: n-propanol > ethanol > methanol > 2-propanol > n-butanol > n-hexane > n-heptane > n-octane. For the binary solvents, as the mole fraction of good solvent (methanol/ethanol) increased, the solubility of trifloxystrobin increased monotonically at the set temperatures. In addition, the obtained solubility data was correlated with the Apelblat, NRTL, Wilson and Apelblat Jouyban Acree model, and these models were in good agreement with the experimental values. The NRTL model given the results of entropy, enthalpy and Gibbs free energy, which indicated that the dissolution was spontaneous, endothermic and entropically driven. The powder X-ray diffraction patterns proved that there was no polymorphic transformation during the solubility measurement. (C) 2019 Elsevier B.V. All rights reserved.