Recent developments of molecularly imprinted polymer in CEC.

This review focuses on developments in the field of molecularly imprinted polymer (MIP) for CEC since August 2006. New technique of CEC-based MIP, e.g.

Molecularly imprinted polymers as a tool for separation in CEC.

Molecularly imprinted polymers (MIPs) are synthesized in the presence of a template which results in the formation of specific recognition cavities complementary to the template in shape and chemical functionality. One of the most successful application areas of MIPs is chromatographic sorbents, which are tailor-made synthetic polymers for a given analyte. However, low efficiency of MIP columns is often observed because of slow kinetics of the template.

(S)-Ibuprofen-imprinted polymers incorporating gamma-methacryloxypropyl-trimethoxysilane for CEC separation of ibuprofen enantiomers.

In this report, a novel preparation method of molecularly imprinted polymers (MIPs) for CEC was developed. Molecularly imprinted monolithic columns for (S)-ibuprofen were prepared and evaluated, in which charged entities responsible for establishing EOF have been derived from gamma-methacryloxypropyltrimethoxysilane (gamma-MAPS), which was hydrolyzed following copolymerization with 4-vinylpyridine (4-VPY) and ethylene glycol dimethacrylate (EDMA). The EOF and molecular recognition of the stationary phase were investigated in aqueous and nonaqueous media, respectively.

Mechanism of molecular recognition on molecular imprinted monolith by capillary electrochromatography.

The recognition mechanism of molecularly imprinted polymer (MIP) in capillary electrochromatography (CEC) is complicated since it possesses a hybrid process, which comprises the features of chromatographic retention, electrophoretic migration and molecular imprinting. For an understanding of the molecular recognition of MIP in CEC, a monolithic MIP in a capillary with 1,1'-binaphthyl-2,2'-diamine (BNA) imprinting was prepared by in situ copolymerization of imprinted molecule, methacrylic acid and ethylene glycol dimethacrylate in porogenic solvent, a mixture of toluene-isooctane. Strong recognition ability and high column performance (theory plates was 43,000 plates/m) of BNA were achieved on this monolithic MIP in CEC mode.

Chiral recognition ability of an (S)-naproxen- imprinted monolith by capillary electrochromatography.

The racemic naproxen was selectively recognized by capillary electrochromatography (CEC) on an (S)-naproxen-imprinted monolith, which was prepared by an in situ thermal-initiated polymerization. The recognition selectivity of a selected monolith strictly relied on the CEC conditions involved. The factors that influence the imprinting selectivity as well as the electroosmotic flow (EOF), including the applied voltage, organic solvent, salt concentration and pH value of the buffer, column temperature, and surfactant modifiers were systematically studied.

Chiral separation of binaphthol enantiomers on molecularly imprinted polymer monolith by capillary electrochromatography.

A novel enantioseparational monolithic stationary phase for binaphthol based on a molecular imprinting method was introduced and evaluated in capillary electrochromatography (CEC). The monolithic stationary was prepared by the in situ copolymerization of methacrylic acid and ethylene glycol dimethacrylate in a porogenic solvent (toluene or toluene-isooctane) in the presence of an imprinting molecule, (R)-1,1'-bi-2,2'-naphthol. Such stationary phases could separate the enantiomers of binaphthol.

Stereo- and enantioselective determination of pesticides in soil by using achiral and chiral liquid chromatography in combination with matrix solid-phase dispersion.

The separation of enantiomers and diastereomers of 8 commonly used pesticides was investigated by liquid chromatography (LC) using a Chiralcel OD column (cellulose tris-3,5-dimethylphenylcarbamate as the chiral stationary phase) and a Pirkle-type Chirex 3020 column (urea derivative from the reaction of (R)-1-(alpha-naphthyl)ethylamine with (S)-tert-leucine, chemically bonded to 3-aminopropylsilanized silica as the chiral stationary phase). The pesticides studied included one organophosphorus insecticide (phenthoate), 3 triazole fungicides (uniconazole, diniconazole, and propiconazole), and 4 pyrethroids (fenpropathrin, beta-cypermethrin, beta-cyfluthrin, and alpha-fenvalerate). The enantiomers were separated within 20 min with a resolution of > or = 1.

[Advances in the chiral resolution of organophosphorus compounds by liquid chromatography].

The developments in the chiral resolution of organophosphorus compounds by liquid chromatography in recent years are reviewed. Two different approaches of separation: indirect resolution (chiral derivatization reagent method) and direct resolution (chiral mobile phase additive and chiral stationary phase), focusing on several chiral stationary phases--Pirkle type, cyclodextrin, cellulose, ligand exchange and other chiral stationary phases are presented. The possible mechanism of chiral recognition is discussed.

Fast and precise determination of phenthoate and its enantiomeric ratio in soil by the matrix solid-phase dispersion method and liquid chromatography.

A fast and precise method was developed for the determination of phenthoate and its enantiomeric ratio (ER) in three soil samples. A recently developed sample pretreatment technology--matrix solid-phase dispersion (MSPD) was used to extract phenthoate simply and effectively. MSPD conditions, i.