Measurement and Correlation of Solubility of Quizalofop- p -ethyl in Four Binary Mixtures Containing Water from 278.15 to 318.15 K

Abstract

The solubility of quizalofop-p-ethyl in four aqueous binary mixtures, namely n-propanol–water, isopropanol–water, N,N-dimethylformamide (DMF)–water, and N,N-dimethylacetamide (DMAC)–water, was determined using the laser monitoring method over the temperature range from 278.15 to 318.15 K. In all systems, the solubility increased monotonically with increasing temperature and organic cosolvent mole fraction. The experimental solubility data were correlated using the modified Apelblat, the Van’t Hoff–Jouyban–Acree model, and the Wilson models. The correlation performance of these models was evaluated using the relative average deviation (RAD) and root-mean-square deviation (RMSD). Based on the deviation metrics, the modified Apelblat model exhibited the lowest fitting deviations for the present QPE solubility data set under the current fitting framework, with calculated values in good agreement with the experimental data. In addition, Hansen solubility parameter (HSP) analysis was used to qualitatively evaluate QPE–solvent compatibility, suggesting that the observed solvent effects are related to the combined matching of dispersion, polar, and hydrogen-bonding parameters.