Chemical Science International Journal

Ionic     liquid (IL), 1-dodecyl-3-methylimidazolium-3-hydroxy-2-naphthoate (C₁2mimHNC) was synthesized and coated on the surface of NiTi as solid phase microextractiom fiber coating for determination the octadecylamine in brine. Prior to modification with IL, the NiTi was hydrothermally treated for in-situ growth of titanium and nickel oxide composite nanosheets (TiO₂/NiOCNSs). The TiO₂/NiOCNSs fibers coating was oriented  around the NiTi  substrate and  presented  double-faced  open  access  sites,  which provided a desired support framework for the further modification with IL. The extraction performance of C₁₂mimHNC-TiO₂/NiOCNSs fiber coating was evaluated for       detection of octadecylamine (ODA) coupled to HPLC with UV detection. As a result, the C₁₂mimHNC-TiO₂/NiOCNSs fiber coating illustrated excellent adsorption and extraction capability for ODA. The main factors affected extraction efficiency were optimized. Under the optimized  conditions,  good  linearity was  obtained  in  the  range of  1-150  µg/L with correlation  coefficients  (r²)  above  0.985.  Limits of detection (LODs) for  the  developed method was 0.280 µg/L. The proposed method was first applied to extract the ODA in brine samples. Relative recoveries varied from 78.3% to 96.5% at spiking level of 15µg/L and 30 µg/L with the relative standard deviations (RSDs) less than 8.7%.

A method for the determination of metformin hydrochloride (MH) in pharmaceutical formulations by capillary electrophoresis with capacitively coupled contactless conductivity (C⁴D) detection was investigated. The separation was achieved under normal polarity mode at 17.5°C, 30 kV, hydrodynamic injection (50 mbar for 8 s) and using a bare fused silica capillary 72 cm × 75 µm i.d. (detection length, 10.5 cm from the outlet end of the capillary). The optimized background electrolyte consisted of 10 mM 2-morpholinoethanesulfonic acid and 10 mM histidine, pH 6.8. C⁴D parameters were set at fixed amplitude of 100 V and frequency of 650 kHz. Under the optimum conditions, the method shows good linearity over the range of 10-30 µg mL^-1 MH (r²=0.9971). Limits of detection and quantitation based on S/N ratio of 3 and 10 were 0.049 and 0.15 µg mL^-1, respectively. The proposed method was successfully applied to the assay of MH in pharmaceutical formulations and establishing the dissolution profiles for both immediate and extended release formulations of MH.

This study was carried out to examine the alkaline solvolysis of pigmented postconsumer polyethylene terephthalate (PET) in solutions of C₁ – C₃ primary alcohols via microwave heating. The effect of various process parameters such as flake pigmentation, time and sodium hydroxide concentration on the degree of PET degradation and product yield were studied for each alcohol. Response surface methodology (RSM) was used for predicting the optimal conditions for alkaline solvolysis of PET scrap, with Central Composite Design (CCD) for the two parameters chosen as the experimental design. The data obtained from measurement of properties were fitted as second-order equations. The findings of this study showed that the yield is independent of the pigmentation and that microwave-assisted alkaline solvolysis of pigmented postconsumer PET resulted in higher conversion within a shorter processing time, compared to conventional heating methods with identical products obtained in each case.

Bee venom (BV) has a long history of use in Korea for the relief of pain symptoms and for the treatment of various inflammatory diseases, including rheumatoid arthritis. There is some evidence for the underlying mechanisms involved in the venom’s anti-inflammatory and analgesic activities. Recent clinical and experimental reearch has confirmed that the venom and its active components can be applied to a broad spectrum of immunological and neurodegenerative diseases, including autoimmune diseases and Parkinson’s disease. BV has been shown to exhibit these effects by modulating immune cells in the periphery, together with glial cells and neurons in the central nervous system. This review sets out the latest scientific evidence concerning the therapeutic effects of BV and various components thereof in the context of a number of diseases, and provides a detailed description of the mechanisms.

For two decades and beyond, remarkable progress has been made in the use of chemical vapour deposition methods for comprehending 2D materials growth. This review is aimed at providing an overview of several synthesis, characterizations and applications of large area graphene film on some substrates. First, the major growth methods are explained. Next, the mechanism of the graphene growth is discussed, focusing on reaction of precursors, diffusion of adatoms, energetics and kinetics of growth fronts, and effects of substrates. Then, the advantage of growing graphene film on some substrate over another is explained in some of the synthesis. Furthermore, the characterization of the various synthesized graphene films are explained, which suggests a suitable application to it.