Evaluation of fluorous affinity using fluoroalkyl-modified silica gel and selective separation of poly-fluoroalkyl substances in organic solvents

In this study, we focused on the fluorous affinity acting among fluorine compounds, and then developed a new separation medium and evaluated their performance. We prepared the stationary phases for a column using silica gel-modified alkyl fluoride and investigated the characteristics of fluorous affinity by comparing them with a typical stationary phase, which does not contain fluorine, using high-performance liquid chromatography (HPLC). In HPLC measurements, we confirmed that while all non-fluorine compounds were not retained, retention of fluorine compounds increased as the number of fluorine increased with the stationary phase. It also revealed that the strength of fluorous affinity changes depending on the types of the organic solvent; the more polar the solvent, the stronger the effect. Additionally, the stationary phase was employed to compare the efficiency of our column with that of a commercially available column, Fluofix-II. The retention selectivity was almost the same, but the absolute retention strength was slightly higher on our column, indicating that the column is available for practical use.