Magnetism for the Quantification of Sorption in Porous Materials From Liquid Media

A novel adsorption quantification technique applicable to the phenomenon of adsorption from a liquid by solid adsorbents is reported. This new method uses external magnetic fields and a magnetic sample holder to measure the mass changes that take place during the adsorption phenomenon, making it universally applicable to any kind of adsorbate. A similar approach had already been achieved for adsorption from a gas a long time ago, for which gravimetric and volumetric devices had been developed. However, this was not achieved for adsorption phenomena from a liquid that could be applied to any kind of adsorbent. The typical procedure for studying adsorption from a liquid nowadays relies on indirect methods that require determining the concentration of the adsorbate in the initial and final solutions, which may require different analytical techniques depending on the adsorbate/analyte, as well as calibration procedures for each adsorbate/analyte. While this new technique also requires calibration, this is only with respect to the adsorbent. Once completed, it can be used to analyze the adsorption of any adsorbate with limits of detection that range from 1.2 to 4.6% depending on the adsorbent mass employed.