Rapid separations by LC using ion‐exchange media based on spongy monoliths

Novel sponge‐based monoliths containing ionic functional groups were developed for rapid separation and/or concentration of ionic solutes. The cationic and anionic spongy monoliths were prepared by chemical modifications of the pore surface on an original spongy monolith consisting of poly(ethylene‐co‐vinyl acetate). After hydrolysis of the spongy monolith, an anionic or a cationic moiety was introduced with succinyl chloride or acryloyl chloride/diethylamine, respectively. As a result of liquid chromatographic evaluations for the columns packed with these ionic spongy monoliths, both anionic and cationic monoliths showed ionic interactions with the opposing ionic solutes even if a higher flow rate (9.0 mL/min) was employed. Furthermore, we demonstrated the effective and rapid preconcentration of adenosine 5′‐monophosphate in water using column‐switching LC combined with the cationic spongy monolith as an online SPE adsorbent.