Magnetic solid phase extraction polymers

Several extraction techniques have been reported in the literature for the analysis of sulfonamides. Because of their polar nature, sulfonamides are readily extracted by organic solvents ° ° the most commonly used are acetonitrile.Other organic solvents used for analyte extraction and protein precipitation include dichloromethane, " acetone, ethanol, chloroform, and ethyl acetate, " which are often used either alone or in conjunction with one another. Other techniques used for protein precipitation include the use of acids such as perchloric or formic and the use of basic buffers such as potassium hydrogen phosphate and ammonium sulfate. In the case of honey, the use of acids such as trichloroacetic, " " hydrochloric, and phosphoric is necessary for hydrolysis, releasing carbohydrate-bound sulfonamide residues. Other extraction techniques reported in the literature include the use of pressurized liquid extractions, " matrix solid-phase dispersion, and magnetic molec-ularly imprinted polymers. Of additional note, several authors have observed that analyte recoveries were largely... 

The application of a properly timed rf pulse disturbs the net equilibrium magnetization aligned parallel to the magnetic field Hq. The return of nuclear magnetization to equilibrium for solid polymers depends on the chain mobility and is monitored by the FID. The crystalline phase content can be extracted by deconvoluting the decay curve into portions corresponding to crystalline and noncrystalline components. Crystallinity determination of various polyethylene samples by FID NMR based on two- and three-component approaches, as well as... 

---