Novel separation medium spongy monolith for high throughput analyses.

Sponge-like material was utilized as novel chromatographic media for high throughput analyses. The pore size of the sponge-like material was several dozen micrometer, and was named spongy monolith because it consists of continuous structured copolymers, which was made of poly(ethylene-co-vinyl acetate), such as monolithic materials including silica monoliths and organic polymer monoliths. The spongy monolith was packed into a stainless steel column (100 mm x 4.6 mm I.D.) and evaluated in liquid chromatography (LC) with an on-line column-switching LC concentration system. The results indicate that the packed column could be used with high flow rates and low back pressure (9.0 mL/min at 0.5 MPa). Furthermore, bisphenol A was quantitatively recovered by on-line column-switching LC concentration with the spongy monolithic column. Additionally, the adsorption capacity and physical strength of the media was enhanced via chemical modification of spongy monoliths using glycerol dimethacrylate. The results compared with original spongy monolith demonstrated that a higher adsorption capacity was achieved on a shorter column, and a stable low back pressure was obtained at high throughput elution even with a longer column.

Selective adsorption of water-soluble ionic compounds by an interval immobilization technique based on molecular imprinting.

Uniformity recognition sites for water-soluble ionic compounds were constructed onto the pores of porous polymer particles. This concept is based on a modified interval immobilization technique, which was used for the selective recognition of paralytic shellfish poison, saxitoxins (STXs). The results of batch adsorption and solid-phase extraction for one of the STX analogues, a prepared polymer that had special sites for the recognition of STXs, showed that the analogue could selectively recognize and concentrate STXs. Selective recognition was facilitated by interval-immobilized functional groups.