Highlighted articles (October 16, 2014)

By -
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 



Comments

Post a Comment

Popular posts from this blog

Gold coated magnetic beads for electrochemical detection

By -
Image
This post summarizes an interesting article, recently accepted for publication in Analytical Chemistry, which presents an innovative use of magnetic beads. Researchers from the Osaka Prefecture University at Japan have proposed the synthesis of magnetic microbeads covered with a smooth gold layer that are used for the electrochemical detection of streptavidin (1). The synthesis, which is deeply described in the manuscript, consists of three well defined steps. First of all, the magnetic beads are introduced in a colloidal gold dispersion containing Au-nanoparticles (Au-NPs). Thanks to the opposite zeta potential of both materials (microbeads are negatively charged while Au-NPs present a positive charge), their assembly takes place by electrostatic interactions. However, the Au-NPs are not connected to each other and therefore the electrical resistance of the microbeads is too high. In a second step, the modified microbeads are dispersed in an aqueous medium containing HAuCl 4 as ...
Read more

Fabric phase sorptive extraction: a new generation green sample preparation strategy

By -
Image
by Dr. Abuzar Kabir, International Forensic Research Institute, Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, USA Fabric phase sorptive extraction (FPSE), the most recent member of the sorptive microextraction family, has innovatively incorporated both solid phase microextraction (SPME) and solid phase extraction (SPE) techniques into a single technology platform. FPSE utilizes permeable natural/synthetic fabrics e.g., cotton, polyester, fiber glass supports to chemically bind sol-gel hybrid inorganic-inorganic sorbents. A 5 cm2unit of coated fabric (2.5 cm x 2.0 cm) is typically used as the extraction media which can be inserted directly into the sample container. Extraction of the analytes is generally expedited by using a magnetic stir bar to diffuse the analyts into the sample matrix so that rapid mass transfer from the sample matrix to the extraction medium takes place.Once the mass transfer equilibrium between the FPSE media and...
Read more

Rotating Disk Sorptive Extraction

By -
Image
by Prof. Dr. Pablo Richter, Department of Inorganic and Analytical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile. The modern trends in analytical chemistry promote efficiency and green technology in sample preparation. In this context, our research team developed a new technique in 2009 that is capable of extracting pollutants from liquid samples on a rotating PTFE disk with one surface coated with an extraction phase [1]. The disk has embedded a miniature magnetic rod, which allows rotation. We have termed this procedure rotating-disk sorptive extraction (RDSE). RDSE is currently available in two configurations. In the classic version (Figure 1), the extraction phase is a polymeric film adhered to one side of the PTFE disk (configuration 1). In this configuration, polydimethylsiloxane (PDMS), nylon and octadecyl (C18) have been used as the sorptive material for the extraction of low-polarity analytes (Log Kow between 3 and 7) [1-12]. However...
Read more