Application of MIL-53(Al) prepared from waste materials for solid-phase microextraction of propranolol followed by corona discharge-ion mobility spectrometry (CD-IMS).

In this study, MIL-53(Al) metal-organic framework was prepared from waste raw materials. A polyethylene terephthalate (PET) plastic bottle was used as the source of terephthalic acid, and an aluminium beverage can was applied as the precursor of aluminium salt. The activated MIL-53(Al) was immobilized onto a stainless steel probe of the ion mobility spectrometer (IMS), and the coated probe was used for solid-phase microextraction of propranolol from biological samples before determination. The effect of the different parameters such as pH, ionic strength, and stirring rate of the sample, extraction time, and temperature was studied on the extraction efficiency of propranolol. The linearity was obtained ranging from 5-200 µg L-1 with a determination coefficient (R2) of 0.9988, and the detection limit was calculated 1.7 µg L-1 in the water sample. The relative standard deviations of the method were in the range of 2.5-12.2 %. Finally, the method was utilized for determination of propranolol in the tablet sample.

Separation based adsorption of ethanol-water mixture in azeotropic solution by single-walled carbon, boron-nitride and silicon-carbide nanotubes.

The separation of the azeotropic ethanol-water mixture (95.57wt% ethanol) over a wide range of pressures (100-100000kPa) was studied on armchair SWCNTs, SWSiCNTs and SWBNNTs with different diameters at 351.30K using GCMC simulations. The GCMC results demonstrated that ethanol and water molecules form a monolayer single-file, chain together in the center of (6,6) SWCNT, while a spiral ring of ethanol and water is formed in the center of (8,8), (10,10) and (12,12) SWCNTs. It was found that in SWCNTs, the adsorption of ethanol reduces the function of pressure, while water adsorption increases its function. Water selectivity rises as a function of pressure. Also, in SWBNNTs, the adsorption of water increases as a function of pressure, while ethanol adsorption is almost constant. However, in the case of SWSiCNTs, ethanol and water adsorptions are very similar to those of SWBNNTs, whereas the adsorptivities of SWSiCNTs are more than those of SWBNNTs. Our findings regarding adsorption and slope of adsorption indicate that higher pressures are favorable for separating water and ethanol by SWCNTs, while SWBNNTs and SWSiCNTs are demonstrate higher ethanol adsorptivities in lower pressures. Also, MD simulations have been performed to study the microscopic structure and diffusion of binary mixtures of water and ethanol within SWCNTs, SWSiCNTs and SWBNNTs. The MD simulations imply that the oxygen atoms are highly well-organized around themselves. Also, the MD results illustrate a similar tendency for oxygen of water (OW) and oxygen of ethanol (OE) to the wall of the nanotubes in all the pressures. In addition, from the MD results, self-diffusion of water and ethanol in all nanotubes were calculated and discussed.