Microextraction Tech

The potential of ionic liquids (ILs) in the microextraction context is beyond any doubt. ILs, especially those that are liquid at room temperature (RTILs), present a negligible vapour pressure (attractive in HS-SDME), tuneable solubility in water (interesting in in-situ solvent formation technique) and they may be tailored to extract target analytes by the proper selection of the forming ions. RTIL have been extensively used in DLLME for these reasons, its recovery after extraction, being usually developed by centrifugation thanks to their higher density than water. However, this centrifugation step is time-consuming and several alternatives like in-syringe DLLME have been proposed to avoid it. Magnetic materials present a clear advantage over other materials in dispersive procedures as they can be recovered from the bulk solution using an external magnet. The combination of magnetic materials/ionic liquids has been studied from different approaches. For example, ILs can be used t...

Today, we focus the attention on an interesting article recently published in Journal of Chromatography A by researchers from the University of Tasmania at Australia. As our readers well known, electrodriven liquid microextraction techniques present a high efficiency for the extraction of charged analytes. In those techniques, the analytes migrate from the sample to the acceptor phase as a consequence of the voltage gradient established between both phases. In the off-line modes, the involved phases are often physically separated by an organic phase or a polymeric membrane impregnated with an appropriate organic solvent. Our colleagues have proposed a novel configuration that permits the development of the extraction procedure without any physical barrier between phases (1). The device consists of a 20 µL micropipette (a microtube with length of 6.4 cm and inner diameter of 0.3 mm) where the acceptor phase is located. The upper part of the microtube is introduced into a syringe th...

Every month, Analytical Methods journal publishes in its blog a list of hot articles that can be downloaded by free for a defined period of time. This is an interesting initiative that makes wider the impact of the journal providing free access to several articles. I usually read Analytical Methods blog for this reason (among others) and I strongly recommend it to our followers. In fact, this post is focused on one of the latest hot articles of this journal. Solid phase extraction is a consolidated sample preparation technique in any analytical laboratory. In spite of the wide variety of solids commercially available (e.g. silica-C18 and polymeric sorbents), the development of new ones capable of facing up the isolation and preconcentration of hydrophilic and ionic compounds would be desirable. For these compounds the performance of “conventional” sorbents is relatively low. Among the nanostructured solids, graphene and its derivative graphene oxide (GO) have been deeply stud...

by Cameron Low, Digital Editor for Bioanalysis Zone As a reader of the Microextraction Tech blog, and as someone who possesses a keen interest in the bioanalytical field, it is a great honor to be able to write this post on Bioanalysis Zone . Bioanalysis Zone is brought to you by Future Science Group, the publishers of Bioanalysis, a prominent fortnightly, peer-reviewed journal. The site features the latest news relevant to those working within the bioanalytical field; articles from Bioanalysis; exclusive interviews and commentaries from opinion leaders working within academia and the pharmaceutical industry; exclusive webinars with a variety of experts; and a business directory. We also provide a forum for the community to discuss recent developments and pose any questions related to this fast moving field. Fabio Garofolo, Associate Editor of Bioanalysis, commented, “I truly believe that since bioanalytical science, techniques and regulations are evolving so fast, it is i...

If you are interested in green analytical chemistry, this is an article for you. Researchers from the Wuhan University at China have recently proposed the use of pollen grains as sorbent in hydrophilic interaction solid phase extraction (1). These grains are characterized by a high superficial area (close to 20 m2/g), a high hydrophilic surface due to the presence of residual hydroxyl groups and particle size in the medium micrometer range. The selection of the proper variety of pollen to be used for analytical purposes is a critical issue according to the authors. They prefer pine pollen to bee pollen grains since the first one is more homogeneous from the chemical point of view and therefore it leads to more reproducible results. In addition, this type of pollen is available at higher amounts allowing the fabrication of many extraction cartridges for sample extraction. Figure 1. Pollen from a variety of common plants (Public domain image from wikipedia) Pollen grains cannot...

Working to Automate Micro-Extraction I am a regular reader of this blog, which I find relevant and interesting, so I am pleased to have this opportunity to introduce the Anatune blog to a wider audience and encourage more people to read it. Anatune is a company based in Cambridge, UK and we specialise in the automation of GC-MS sample preparation and injection. We provide upgrades to existing instruments, but best of all, we like to deliver complete, integrated systems where the sample preparation works seamlessly with GC-MS. ( Read more ) Stir bar sorptive dispersive microextraction mediated by magnetic nanoparticles We all are familiar with stir bar sorptive extraction (SBSE) and dispersive methodologies in this context. The advantages of both techniques are also well known and a deep research is being carried out to characterize new sorbent phases which improve the efficiency and open up the application field of these microextraction techniques. Research ...

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...