Microextraction Tech

Design and fabricate your own extraction devices in a cheap and rapid way. This is the main conclusion that we can infer after reading an article recently accepted for publication in Analytical Chemistry. This dream has come true by our colleagues form the National Tsing-Hua University at Taiwan (1). They have designed a solid phase extraction device which has been finally fabricated in acrylate using a 3D printer. The fabrication time (approximately 38 min) and the cost of each unit (US$ 1.5) are really motivating. The extraction device consists of a microfluidic channel where cuboids of defined dimensions are printed on surface to increase the superficial area and thus the extraction kinetics. The device presents a high permeability, it allows the use of high sample flow rates (essential to pass larger sample volumes allowing high preconcentration factors) and it is easy to regenerate. In addition, it can be easily adapted to flow systems as it can work with low-pressure pumping...

Membranes can be used for different purposes in Analytical Chemistry. In the extraction context, they permit the development of several liquid-liquid extraction techniques such as dialysis, osmosis, among others. Also, they can provide an additional enhancement of the selectivity by the direct selection of the pore size. They are also commercialized in different formats (planar, tubular) and polarities in such a way that they can be applied to almost any analyte-sample binomial. In liquid phase microextraction, membranes have been used under the 2 phases and 3 phases formats depending on the number, nature and role played by the different liquid phases involved. In order to favor the kinetic of the whole process the continuous agitation of the system is recommended to accelerate the diffusive transport of the target compounds in both the donor and acceptor phases reducing the thickness of the diffusion layer near the membrane. Prof. Dr March and Prof. Dr. Cerdá have recently pro...