1991 Volume 7 Issue Supple Pages 1535-1538
Solid phase or polymeric reagents perform derivatizations of nucleophiles in a heterogeneous manner, wherein the analyte in solution migrates to the reaction center, now immobilized on the solid support. Reactivities can be engineered as function of the nature of the leash holding the final tag to the polymeric support, the active center where the reaction actually occurs, and the nature of the organic or inorganic polymer itself. The polymer plays a direct role in such solid phase reactions, whereby its pore size, pore diameter, surface area, hydrophobicity, and other physical paramaters (e.g., swelling), can all be involved in nucleophilic displacement type reactions. Microenvironments can accelerate or decelerate kinetics of heterogeneous reactions, force reactions to be more selective, and improve reaction kinetics. Polymeric reagents have been used to perform both on- and off-line derivatizations in a wide variety of solvents, usually pre-column in HPLC. They can be used for both achiral and chiral reactions, to determine both chemical and enantiomeric purity of analytes, often present in complex biological matrices, without any sample pre-treatment or clean-up. Both direct and indirect enantiomeric recognition can be assisted by polymeric type derivatizations, greatly simplifying sample pre-treatment steps and requirements. Mixed-bed reactions can form several derivatives simultaneously, all or some of which can then be used to identify an analyte and its quantitative level in a complex sample matrix. Reaction conditions, often on-line, precolumn, can be varied to improve analyte identification and determination, via direct comparisons with an authentic standard in the same or a similar sample matrix.
