Membrane chromatographic system applications

MAJOR APPLICATIONS Membranes, chromatographic resins, size exclusion particles, drug delivery systems. 

The application of potentiometric detection in ion-chromatography is favoured by the progress in the field of membrane ion-selective electrodes (ISE). The electrodes with solid-state membranes were mostly employed for determination of halides, pseudohalides and some other anions binding silver ions. The use of fluoride electrode in multidetector, chromatographic system offers very low detection limit of 1.2 ng fluoride in injected samples. Application of bromide electrode in the same system provides even five-fold better detectability. The same level of detectability was reported by Butler and Gershey for iodide with iodide ISE. In the system with preconcentration step the detectability can be lowered by an order... 

Amorphous silicas play an important role in many different fields, since siliceous materials are used as adsorbents, catalysts, nanomaterial supports, chromatographic stationary phases, in ultrafiltration membrane synthesis, and other large-surface, and porosity-related applications [16,150-156], The common factor linking the different forms of silica are the tetrahedral silicon-oxygen blocks if the tetrahedra are randomly packed, with a nonperiodic structure, various forms of amorphous silica result [16]. This random association of tetrahedra shapes the complexity of the nanoscale and mesoscale morphologies of amorphous silica pore systems. Any porous medium can be described as a three-dimensional arrangement of matter and empty space where matter and empty space are divided by an interface, which in the case of amorphous silica have a virtually unlimited complexity [158],... 

A consequence of MESI application is the membrane introduction mass spectrometry system (MIMS), which allows selective extraction of VOCs and direct MS analysis without chromatographic separation. The gaseous substances permeate through the highly hydrophobic membrane and are introduced directly to a mass spectrometer [115-118]. 

Multifunctional reactors. Apart from the applications exclusively in the reaction engineering field, fixed beds can also be found integrated in apparatus with separation purposes. Two major classes can be identified membrane [16, 17] and chromatographic (adsorptive) reactors [18]. In both cases, a familiar configuration involves a packed bed with a permeable, selective wall and/or packed with a catalyst/ adsorbent. The latter is found in simulated moving bed reactors [19, 20], which can be seen as an arrangement of several of these beds. The overall effect from the coexistence of reaction and separation functionalities is the increase of conversion in equilibrium-limited systems, which are shifted due to the simultaneous separation of the products. 

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