Highlighted articles (October 16, 2014)

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We recommend the following articles that deal with different aspects related with sample preparation.

1. Molecularly imprinted polymer dedicated to the extraction of glyphosate in natural waters. Glyphosate is a widely employed pesticide. Glyphosate determination is challenging due to its small size and high polarity. In this article, researchers from the University of Orleans at France have proposed a new molecularly imprinted polymer (MIP) that allows, thanks to electrostatic and polar interactions, the isolation of this analyte from natural waters. The MIP showed higher selective recognition toward the target analyte than the obtained with the non-imprinted polymer (NIP). Although the pH and ionic strength are critical variables on the analyte extraction, this method is a promising tool for the resolution of this complex analytical problem. Link to the article

2. Water-contained surfactant-based vortex-assisted microextraction method combined with liquid chromatography for determination of synthetic antioxidants from edible oil. In this article, vortex assisted microextraction is adapted to the extraction of oily samples. The concepts is simple, the oily sample is extracted with an aqueous solution containing a surfactant as emulsification reagent. Both phases are completely mixed and after the extraction and phases´ separation, the resulting aqueous phase (containing the analytes) is analyzed by HPLC. The approach has been applied for the determination of several synthetic antioxidants. Link to the article

3. Nano sponge Mn2O3 as a new adsorbent for the preconcentration of Pd(II) and Rh(III) ions in sea water, wastewater, rock, street sediment and catalytic converter samples prior to FAAS determinations. Nano sponge of Mn2O3 is presented for the first time for the extraction of metal ions in several matrices. The synthesis of that material comprises a limited number of steps which makes easy the in-lab production. The resulting material is characterized by a high surface area (6.6 m2/g) and a pore size of 55.1 nm. The application of the material is rather simple and the extraction and elution of the target analytes can be achieved in less than 2 min which also corroborates the high superficial area of the synthesized material. The nano sponge can be also reused a hundred of times with a negligible effect on the performance. Its use in combination with FAAS allows the determination of Pd(II) and Rh(III) at the low mg/L level. Link to the article

4. Magnetic dummy molecularly imprinted polymers based on multi-walled carbon nanotubes for rapid selective solid-phase extraction of 4-nonylphenol in aqueous samples. Carbon nanotubes are proposed as extraction support in this application. First of all, the carbon nanotubes are oxidized to produce carboxylic groups in their surface. In a second step, carbon nanotubes are immersed in a solution that contains Fe3+ as magnetic precursor in such a way that the solution fills the inner volume of the nanoparticle. After this treatment the magnetic nanoparticles are synthesized giving as a result carbon nanotubes with a magnetic core. In the last step, the outer surface of the carbon nanotubes is coated with a thin film of a molecularly imprinted polymer. This material has been employed for the extraction 4-tert-octylphenol from water samples. The new sorbent presents a maximum extraction capacity of 52.4 mg/g which is higher than that provided by the non-imprinted one. Link to the article 



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