The identification of synthetic cannabinoids surface coated on herbal substrates using solid-state nuclear magnetic resonance spectroscopy.

Solid-state 13C and 19F NMR spectroscopy offers a non-destructive, highly selective protocol for the identification of forensically relevant synthetic cannabinoids on herbal substrates. Using this technique, well resolved 13C spectra were obtained that readily enabled structural identification; in some instances complemented by 19F spectral data. The approach described has potential for related applications such as the direct detection of pesticides on plants.

The influence of the size and symmetry of cations and anions on the physicochemical behavior of organic ionic plastic crystal electrolytes mixed with sodium salts.

The phase behaviour, ionic conductivity, electrochemical stability and diffusion coefficients of mobile components in three organic ionic plastic crystals (OIPCs): triisobutylmethylphosphonium bis(fluorosulphonyl)amide (P1i444FSI), triisobutylmethylphosphonium bis(trifluromethanesulphonyl)amide (P1i444NTf2) and trimethylisobutylphosphonium bis(trifluoromethanesulphonyl)amide (P111i4NTf2) are compared to study the effect of the anions and cations on phase behaviour and dynamics. The FSI-based OIPC shows lower melting point and higher conductivity values most likely because of the higher degree of charge distributions and weaker ion-ion interactions compared to NTf2 anion-based OIPCs. Cyclic voltammetry of electrolytes consisting of these OIPCs with 70 mol% sodium salt incorporated indicates stable sodium plating/stripping behaviour at 70 and 50 °C for all samples. The magnitude of the peak currents, however, are much higher for the FSI-based electrolyte.

Controlled delivery of antimicrobial gallium ions from phosphate-based glasses.

Gallium-doped phosphate-based glasses (PBGs) have been recently shown to have antibacterial activity. However, the delivery of gallium ions from these glasses can be improved by altering the calcium ion concentration to control the degradation rate of the glasses. In the present study, the effect of increasing calcium content in novel gallium (Ga2O3)-doped PBGs on the susceptibility of Pseudomonas aeruginosa is examined. The lack of new antibiotics in development makes gallium-doped PBG potentially a highly promising new therapeutic agent. The results show that an increase in calcium content (14, 15 and 16 mol.% CaO) cause a decrease in degradation rate (17.6, 13.5 and 7.3 microg mm(-2) h(-1)), gallium ion release and antimicrobial activity against planktonic P. aeruginosa. The most potent glass composition (containing 14 mol.% CaO) was then evaluated for its ability to prevent the growth of biofilms of P. aeruginosa. Gallium release was found to reduce biofilm growth of P. aeruginosa with a maximum effect (0.86 log(10) CFU reduction compared to Ga2O3-free glasses) after 48 h. Analysis of the biofilms by confocal microscopy confirmed the anti-biofilm effect of these glasses as it showed both viable and non-viable bacteria on the glass surface. Results of the solubility and ion release studies show that this glass system is suitable for controlled delivery of Ga3+. 71Ga NMR and Ga K-edge XANES measurements indicate that the gallium is octahedrally coordinated by oxygen atoms in all samples. The results presented here suggest that PBGs may be useful in controlled drug delivery applications, to deliver gallium ions in order to prevent infections due to P. aeruginosa biofilms.

A (27)Al MAS NMR study of a sol-gel produced alumina: Identification of the NMR parameters of the theta-Al(2)O(3) transition alumina phase.

(27)Al MAS NMR has been used to study a sol-gel prepared alumina annealed at various temperatures. Two-field simulation of the sample heated to 1200 degrees C confirmed the presence of corundum, as suggested by XRD, and also the presence of nanocrystalline theta-Al(2)O(3). (27)Al MAS NMR chemical shifts, quadrupolar coupling constants and asymmetry parameters are reported for the tetrahedral and octahedral aluminium sites within theta-Al(2)O(3).

A 27Al, 29Si, 25Mg and 17O NMR investigation of alumina and silica Zener pinned, sol-gel prepared nanocrystalline ZrO2 and MgO.

Alumina and silica Zener pinning particles in sol-gel prepared nanocrystalline ZrO2 and MgO have been characterised using 27Al and 29Si MAS NMR after annealing at various temperatures up to 1200 degrees C. The structures of the pinning phases were found to differ not just between the two metal oxide systems but also depending on the exact method of manufacture. Three distinct transitional alumina phases have been observed in different alumina-pinned samples annealed at 1200 degrees C, one in particular identified by a peak at a shift of 95 ppm in the 27Al NMR spectrum. Both the alumina and silica pinning phases reacted with the MgO nanocrystals, forming spinel in the case of alumina, and enstatite and forsterite in the case of silica. Despite reacting readily with the MgO, the silica pinning particles were effective at restricting grain growth, with 11 nm MgO nanocrystals remaining after annealing at 1000 degrees C.