Dispersive solid-phase extraction based on magnetic dummy molecularly imprinted microspheres for selective screening of phthalates in plastic bottled beverages.

A new magnetic dummy molecularly imprinted dispersive solid-phase extraction (MAG-MIM-dSPE) coupled with gas chromatography-FID was developed for selective determination of phthalates in plastic bottled beverages. The new magnetic dummy molecularly imprinted microspheres (MAG-MIM) using diisononyl phthalate as a template mimic were synthesized by coprecipitation coupled with aqueous suspension polymerization and were successfully applied as the adsorbents for MAG-MIM-dSPE to extract and isolate five phthalates from plastic bottled beverages. Validation experiments showed that the MAG-MIM-dSPE method had good linearity at 0.

New ionic liquid modified polymeric microspheres for solid-phase extraction of four Sudan dyes in foodstuff samples.

The new ionic liquid modified polymeric microspheres (ILPM) were synthesized by precipitation polymerization using 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]) as the functional monomer, divinylbenzene (DVB) as the cross-linker, and a mixture of toluene and acetonitrile as the dispersant solvent. The obtained ILPM showed good adsorbability to the four kinds of Sudan dyes and were successfully applied as a special sorbent of solid-phase extraction (SPE) coupled with high-performance liquid chromatography (HPLC) for the simultaneous isolation and determination of four Sudan dyes from foodstuff samples. Compared with the traditional SPE adsorbents such as neutral alumina and C18, the ILPM sorbents provided higher recovery with a significant purification effect.

Molecularly imprinted solid-phase extraction coupled to liquid chromatography for determination of Sudan dyes in preserved beancurds.

New molecularly imprinted microspheres synthesized by suspension polymerisation using phenylamine and naphthol as mimic template were successfully applied as selective sorbents for the solid-phase extraction used for the simultaneous determination of four Sudan dyes from preserved beancurd products. The obtained imprinted microspheres showed good recognition and selectivity to the four Sudan dyes in aqueous solution and the affinity could be easily controlled by adjusting the property of the solution. Under the selected experimental condition, the recoveries of the Sudan dyes in preserved beancurds at three spiked levels were ranged between 90.

Miniaturized matrix solid-phase dispersion combined with ultrasound-assisted dispersive liquid-liquid microextraction for the determination of three pyrethroids in soil.

A simple and miniaturized pretreatment procedure combining matrix solid-phase dispersion (MSPD) with ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) technique was proposed in first time for simultaneous determination of three pyrethroids (fenpropathrin, cyhalothrin and fenvalerate) in soils. The solid samples were directly extracted using MSPD procedure, and the eluent of MSPD was used as the dispersive solvent of the followed DLLME procedure for further purification and enrichment of the analytes before GC-ECD analysis. Good linear relationships were obtained for all the analytes in a range of 5.

Determination of dicofol in aquatic products using molecularly imprinted solid-phase extraction coupled with GC-ECD detection.

The novel molecularly imprinted microsphere (MIM) that could be applied as special sorbent was synthesized by aqueous suspension polymerization using 1,1-bis(4-chlorophenyl)-1,2,2,2-tetrachloroethane (α-chloro-DDT) as the dummy template. The obtained MIM exhibited good recognition and selectivity to dicofol and it was successfully applied as selective sorbent of solid-phase extraction for the determination of dicofol from aquatic products. At the optimum conditions of the molecularly imprinted solid-phase extraction (MISPE) coupled with GC-ECD, good linearity for dicofol was achieved in a range of 0.

Determination of ofloxacin and lomefloxacin in chicken muscle using molecularly imprinted solid-phase extraction coupled with liquid chromatography.

A new molecularly imprinted solid-phase extraction (MISPE) procedure combined with liquid chromatography was developed for the simultaneous selective extraction and determination of ofloxacin (OFL) and lomefloxacin (LOM) in chicken muscle samples. The water-compatible molecularly imprinted microspheres (MIMs) were synthesized by aqueous suspension polymerization using 2-hydroxy-3-naphthoic acid and 1-methylpiperazine as mimic templates. The MIMs applied as selective sorbents in SPE method showed high selectivity and affinity to OFL and LOM in complex biological matrices.

Molecularly imprinted solid-phase extraction combined with ultrasound-assisted dispersive liquid-liquid microextraction for the determination of four Sudan dyes in sausage samples.

A simple and highly selective molecularly imprinted solid-phase extraction (MISPE) combined with ultrasound-assisted dispersive liquid-liquid microextraction (DLLME) was developed for the determination of four Sudan dye (I, II, III, and IV) residues in sausage products. The novel molecularly imprinted microspheres (MIMs) synthesized by aqueous suspension polymerization using phenylamine-naphthol as the dummy template show high affinity to the four Sudan dyes and were applied as selective sorbents of MISPE-DLLME to overcome the drawbacks of template leakage in quantitative analysis. Good linearity was obtained in a range of 0.

Molecularly imprinted matrix solid-phase dispersion combined with dispersive liquid-liquid microextraction for the determination of four Sudan dyes in egg yolk.

A new kind of aniline-naphthol molecularly imprinted microsphere (MIM) synthesized by aqueous suspension polymerization was applied as a selective sorbent of miniaturized matrix solid-phase dispersion combining with dispersive liquid-liquid microextraction (MSPD-DLLME) for the simultaneous determination of four Sudans in egg yolk samples. The solid sample was directly blended with MIM in MSPD procedure and the eluent of MSPD was used as the dispersive solvent of the followed DLLME for further purification and enrichment of the analytes before HPLC analysis. Good linearity for all the Sudan dyes was ranged from 0.