Selective involving solid/liquid systems

The reaction mechanism of this system involved the transfer of phases across the solid liquid interface. Hence, quantification using Equation (22) produced values that were overestimated. To determine the absolute phase abundances, powdered diamond was selected as an inert internal standard and was weighed into the starting solids. Acid was then added to this mixture and the standard concentration taken as its weight fraction of the sample in its entirety, i.e., solids and liquids in total. For each dataset the results of the quantitative phase analysis were adjusted according to the known amount of standard present in the system [Equation (16)]. This allowed the determination of variation in the amorphous content of the system to be assessed via Equation (17)] as well as the formation and consumption of crystalline phases. The amorphous content... 

MAE is thus another special case of liquid extraction accelerated by increasing the temperature of the solvent. It differs from traditional solvent extraction (including the Soxhlet method) by the fact that the heat is generated internally within the solvent-solid matrix system wherever the microwaves can interact with solvent molecules, including within any pores in the solid. MAE differs from SAE by the fact that no spectacular localized hot spots are involved. In addition, because of the mechanism involved, different solvents have different properties with respect to microwave radiation and this provides a degree of selectivity for MAE by adjusting the nature of the solvent. The principal molecular properties involved in response to a microwave field are the dipole moment of the solvent and the extent of nonbonding interactions... 

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