In this research, solubility of l-tryptophan in water, methanol, ethanol, acetone, isopropanol, n-butanol, acetonitrile, ethyl acetate, organic pure solvent, and in three binary mixed solvents (water + acetonitrile), (water + methanol), and (water + isopropanol) at the temperature range of T = 278.15–333.15 K was determined with the gravimetric method. The experimental results show that the solubility of l-tryptophan in the above solvents increased as temperature rose, and it achieved the highest dissolution efficiency in water. The improved Apelblat model, the Buchowski–Ksiazaczak λh model, the Redlich–Kister (CNIBS/R–K) model, and the Jouyban–Acree model were used to nonlinearly fit the experimental data of solubility, and the consistency was good. The physicochemical information of l-tryptophan provided in this report may be helpful for its extraction/separation, recrystallization, purification, and formulation development.

In the study, the solubility of l-serine were measured in eight common pure solvents and binary mixed solvents (acetonitrile + water, isopropanol + water, methanol + water, and acetone + water) from 278.15 to 333.15 K under atmospheric pressure by gravimetric method (acetone was measured from 278.15 to 328.15 K). The solubility of l-serine increases with increasing temperature, and the order in eight common pure solvents is water > acetonitrile > methanol > acetone > ethyl acetate > ethanol > n-butanol > isopropanol. In binary mixed solvents, the solubility of l-serine is dependent on temperature and solvent composition. Also, the solubility of l-serine increases with increasing temperature, and it decreases as the concentration of acetonitrile, isopropanol, methanol, or acetone increases at a constant temperature. The experimental data in eight pure solvents were fitted by the modified Apelblat model, Buchowski–Ksiazaczak λh model. The modified Apelblat equation, combined nearly ideal binary solvent/Redlich–Kister (CNIBS/R–K) model, and Jouyban–Acree model were used to correlate the experimental data in four binary solvents. Among the four models, the modified Apelblat model is more suitable with a higher accuracy than the other three models. The experimental data can be used to optimize the industrial manufacturing process of l-serine.

Buprofezin is a kind of insecticide and an important chemical intermediate product. Data on solid−liquid equilibrium of buprofezin in different solvents is essential for the area of industrial applications. In this work, the solubility of buprofezin in methanol, ethanol, isopropanol, n-butanol, acetonitrile, n-hexane, ethyl acetate, N,N-dimethylformamide, and two binary solvent mixtures (methanol + ethyl acetate and acetonitrile + ethyl acetate) was measured at the temperature range of 278.15−328.15 K at atmospheric pressure by the gravimetric method. The experimental values showed that elevated temperatures increased the solubility of buprofezin in all selected solvents. The modified Apelblat model, the Buchowski− Ksiazaczak λh model, combined nearly ideal binary solvent/Redlich−Kister (CNIBS/R-K) model, Jouyban−Acree model, and an ideal model were used to describe and predict the diversification trend of solubility.