Development of fluorinated, monolithic columns for improved chromatographic separations of fluorous-tagged analytes

With applications that take advantage of highly selective fluorine–fluorine interactions appearing with greater frequency in the literature, the development of porous polymer monoliths from fluorous components is reported here for the purpose of chromatography of tagged analytes. With potential uses in fields as diverse as separation science and proteomics, facile fabrication of materials with fluorous specificity that can be applied in a high-throughput manner is greatly desirable. To this end, we have developed porous polymer capillary columns with varied fluorous content using a simple UV-initiated radical polymerization process and characterized them using flow-induced backpressure and scanning electron microscopy (SEM). With structural similarities assured (visually, and by backpressure variations of less than 42%), the monoliths were tested as chromatographic columns for the separation of a series of fluorous-tagged analytes under gradient conditions. It was found that columns made with fluorinated components exhibited greater selectivity for fluorous analytes than did equivalent, non-fluorinated monoliths, retaining analytes with either one or two fluorous tags for approximately 6% and 13% longer, respectively. This supports the idea of differences existing between fluorous and reverse-phase separation mechanisms, and encourages a broader range of potential applications for fluorous monoliths of this type.