Functional solid phase extraction

Peterson DS, Rohr T, Svec FK, Frechet JMJ (2003) Dual-function microanalyt-ical device by in situ photolithographic grafting of porous polymer monolith integrating solid-phase extraction and enzymatic digestion for peptide mass mapping. Anal Chem 75 5328... 

Initial Fractionation. The most effective method found for the initial fractionation of the complex enzyme mixtures present in wood-culture extracts was anion exchange chromato phy eluting with salt gradients (9,74,75). This permitted further sample concentration by functioning as a solid phase extractant during loading. It also showed higher sample capacity and better separations than other methods. 

In some instances, combinations of normal- and reversed-phase columns can also be used for better purification of the crude extract. Combinations of Ci8 and alumina or Cig and silica solid-phase extraction columns have been successfully employed in the analysis of ivermectin residues in animal tissues (346) and bovine plasma (348), respectively. Elimination of coextracted materials and concentration of the analytes has also been accomplished using mixed-phase extraction columns. Such a copolymeric bonded silica column with both hydro-phobic and cationic functions has been employed in the analysis of hygromycin B in plasma, serum and milk (326). 

Support materials for solid phase extraction (SPE) and for chromatographic techniques have been prepared by ROMP. pH-stable high capacity stationary phases have been prepared by copolymerization of functional monomers with a suitable crosslinking agent, with precipitation polymerization techniques. 

D.L. Ambrose, J.S. Fritz, M.R. Buchmeiser, N. Atzl, and G.K. Bonn, New, high-capacity carboxylic acid functionalized resins for solid-phase extraction of a broad range of organic compounds,/. Chromatogr. A, 786(2) 259-268, October 1997. 

Just as the interiors of micelles in water provide a hydrophobic environment to solubilize chlorobiphenyls and then photodegrade them by reductive dechlorination, so do octadecyl-functionalized silica gel [89], normally used as reverse phase packing in HPLC and for solid-phase extraction, and the hquid-semisohd polydimethylsiloxane [-OSi(CH3)2 -] [90,91], also used for solid-phase extraction. In both media, reductive dechlorination is the primary photochemical pathway. 

Solid-phase extraction (SPE) is based on low-pressure liquid chromatography, where a short column is filled with an adsorbent. The separation mechanisms are based on the intermolecular interactions among analyte molecules and functional groups of sorbent. The choice of eluent is made by the relationship between the eleutropic value (2°) and the analyte polarity. SPE is fast, selective, and economical if compared with the extraction methods described previously. It can be applicable to both nonpolar and polar analytes, but both matrix and analyte must be in the liquid state. 

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