[Application of FTIR technique in microwave-hydrothermal synthesis of saponite].

FTIR was employed in the structure analysis of the saponites with an ideal chermical formula [Si6.5Al1.5]IV [Mg6]VI O20(OH)4 the starting gel synthesized by microwave-hydrothermally under different pressures (1 x 10(5), 5 x 10(5), 1.5 x 10(6), 2.5 x 10(6) and .5 x 10(6) Pa). It was found that low frequency absorption region in infrared spectrum was sensitive to the crystallization of the product and the amorphous materials produced in synthesis of saponite under the radiation of microwave. The absorptions belong to amorphous materials were decreased with increasing pressure. Saponite synthesized at 3.5 x 10(6) Pa showed no amorphous absorptions (1240, 90-602 cm(-1)), indicating the purity and quality of the synthetic mineral. It was worthy to note that Si(AI)-O stretching vibration infrared absorption could be regarded as an index in assessing the quality of synthetic 2:1 trioctahedral smectite sample with the same chemical compositions. With the increasing pressure, this strong vibration shifted to low frequency (1022, 1020, 1016, 1016, 1005 cm(-1)) in the medium frequency of the whole infrared spectrum. Since the sensitivity, easiness and simplicity, this infrared index would be meaningful in practical saponite-related minerals analysis. In addition, powder X-ray diffraction and scanning electronic microscopy were employed in charactering the saponite synthesized by microwave-hydrothermal method in this work.

Evidence for the 2:1 molecular recognition and inclusion behaviour between beta- and gamma-cyclodextrins and cinchonine.

Cinchonine (Cin) is the primary drug of choice in the treatment of malaria, but its poor solubility has restricted its use via the oral route. Cyclodextrins (CDs) form inclusion complexes with cinchonine to form soluble complexes. This interaction was investigated by solubility studies, electrospray ionization mass spectrometry (ESI-MS), and molecular modeling. ESI-MS evaluated successfully the nature of the solution-phase inclusion complexes. The experimental results showed that not only 1:1, but also stable 2:1 inclusion complexes can be formed between CDs and Cin. Multi-component complexes of beta-CD-Cin-beta-CD (1:1:1), gamma-CD-Cin-gamma-CD (1:1:1), and beta-CD-Cin-gamma-CD (1:1:1) were found in equimolar beta- and gamma-CD mixtures with Cin. The formation of 2:1 and multi-component 1:1:1 non-covalent CD-Cin complexes indicates that beta- and gamma-CD are able to form sandwich-type inclusion complexes with Cin in high concentrations. The phase-solubility diagram showed non-linear type A(p) profile, indicating that more than one cyclodextrin molecule is involved in the complexation of one guest molecule. Molecular modeling calculations have been carried out to rationalize the experimental findings and predict the lowest energy molecular structure of inclusion complex.

[Spectral analysis of maorenshen (Actinidia valvata) and its confusable materials].

This article reports the spectral analysis of Maorenshen (Actinidia valvata) and its confusable materials Actinidia chinennsis and Actinidia polygama by fluorescence test, ultraviolet spectrophotometry and fluorescence spectrophotometry. Strong green or blue fluorescence was observed at UV 254 nm in aqueous solutions of Actinidia chinesis and Actinidia polygama, and was barely seen in that of Maorenshen. There were also obvious differences among the ultraviolet spectra and fluorescence spectra of the extracted solutions of the three materials. No obvious absorption band was observed in the UV spectra of ethanol-extracted solution of Maorenshen, an absorption band at 280 nm was observed in the UV spectra of Actinidia chinensis and Actinidia polygama in ethanol extract-solutions. There were also different wavelength and strength in fluorescence spectra among extracted solutions of Maorenshen, Actinidia chinensis and Actinidia polygama. Therefore, it is feasible to identify Maorenshen (Actinidia valvata) and its confusable materials by ultraviolet spectrophotometry and fluorescence spectrophotometry.