Read all posts from December 2015

By -

Magnetic SPME in micro-fluidics, speciation of Hg in cells

Mercury is a well known toxicant with different exposure sources. Although its use on medical products is banned in many countries, other sources like environmental pollution or contaminated food still exist. Professor Bin Hu and co-workers have been recently researched how Hg species are distributed and even modified in cell cultures [1]. In their own words, this type of research is of paramount importance in order to fully understand the toxicity but also the cell protection mechanisms. (post)

Polypyrrole coated nylon fibers for disk-based solid phase extraction

The extraction of polar compounds from aqueous matrices is not a easy process due to the high solubility of these compounds into the sample that weakens the interactions with the extractant. Polymeric phases, comprising different monomer in their structure that may establish polar interactions and even ionic, have been widely used to solve this problem. Although there are some commercially available phases, the development of novel ones as well as the design of formats different than the conventional particle-packed column one are attractive research lines (post)

Molecularly imprinted polymers on the surface of TiO2 nanoparticles

The usefulness of molecularly imprinted polymers is unquestionable. They have been extensively used for the selective extraction of different families of compounds in a wide variety of samples. The main problem associated to these sorbents is the impossibility to ensure that a high percentage of the recognition sites are available for analyte interaction as they can be embebed into the polymeric structure. (post)

Rapid extraction of nucleic acids for quick diagnosis

Nucleic acids have several practical applications in Analytical Sciences as they can be used as biorecognition molecules (e.g. aptamer) in the design of sensors and even extraction phases. However, this post deals with those methods that are aimed to determining nucleic acids in samples of different origin (usually biosamples).(post)

Laser desorption combined with SPME for GC-MS analyses


We highlight today an article that describes the combination of laser desorption and solid phase microextraction (SPME) for the analysis of solid samples. The article has been published in Rapid Communications in Mass Spectrometry under the title "Laser desorption sample transfer for gas chromatography/mass spectrometry" (1). It is not necessary to describe the potential of SPME since it is a well established technique in almost every analytical laboratory.(post)

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