نتایج جستجو برای: atr spectroscopy
تعداد نتایج: 176150 فیلتر نتایج به سال:
Different yew species contain poisonous taxane alkaloids which serve as resources for semi-synthesis of anticancer drugs. The highly variable amounts of taxanes demand new methods for fast characterization of the raw plant material and the isolation of the target structures during phyto extraction. For that purpose, applicability of different vibrational spectroscopy methods in goods receipt of...
This study examines the effects of particle sizes between 3 and 121 μm on the fundamental vibrations of the [CO3(2-)] anion in calcite [CaCO3] as analyzed by total attenuated reflectance infrared spectroscopy (ATR-IR) and Raman spectroscopy (RS). The ATR-IR absorbance intensity ratios of the [ν4/ν3] [712 cm(-1)/1393 cm(-1)], [ν4/ν2] [712 cm(-1)/871 cm(-1)], and [ν2/ν3] [871 cm(-1)/1393 cm(-1)] ...
BACKGROUND This study was conducted to develop fast and cost effective methods for the determination of caffeine in green coffee beans. In the present work direct determination of caffeine in aqueous solution of green coffee bean was performed using FT-IR-ATR and fluorescence spectrophotometry. Caffeine was also directly determined in dimethylformamide solution using NIR spectroscopy with univa...
With cotton fiber growth or maturation, cellulose content in cotton fibers markedly increases. Traditional chemical methods have been developed to determine cellulose content, but it is time-consuming and labor-intensive, mostly owing to the slow hydrolysis process of fiber cellulose components. As one approach, the attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy...
In this paper, FTIR spectroscopy using attenuated total reflection (ATR) and KBr pressed disk techniques has been used to characterize sorbed water and HDTMA+ in organo-clay. Sorbed water content decreases with the intercalation of HDTMA+. With the decrease of the sorbed water content, the position of the nu2 mode shifts to higher frequency dramatically while the stretching vibration shifts to ...
droxide surface sites, characteristics of water a t the interface, and chemical structures of specifically adsorbed molecules. Also, ATR-CIR spectroscopy can qualitatively describe the influence of pH and “inert” electrolyte ions on reactions that occur a t lor near the solid-solution interface. Finally, since signal intensity is not necessarily proportional to the concentration of goethite (un...
Vanadia was incorporated in the 3-D mesoporous material TUD-1 with a loading of 2% w/w vanadia. The performance in the selective photo-oxidation of liquid cyclohexene was investigated using ATR-FT-IR spectroscopy. Under continuous illumination at 458 nm a significant amount of product, i.e. cyclohexenone, was identified. This demonstrates for the first time that hydroxylated vanadia centers in ...
This study is aimed at evaluating the performance of tetrakismethylene-3-3,5-di-tert-butyl-4-hydroxyphenyl propionate methane S1010, tris2,4-di-tert-butylphenyl phosphite S1680 and ascorbic acid AA antioxidants in stabilization of hydroxypropyl cellulose HPC. For this purpose, a number of films with weight percent ratios of 0.4 w/w were prepared in a 1 isopropanol solution w/v. Then, the films ...
Meat, as an important source of protein, is one of the main parts of many people’s diet. Due toeconomic interests and thereupon adulteration, there are special concerns on its accurate labeling.In this study Fourier transform infrared (ATR-FTIR) spectroscopy combined with chemometrictechniques (principal component analysis (PCA), artificial neural networks (ANNs), and partial<...
Evaluation of fresh palm oil adulteration with recycled cooking using GC-MS and ATR-FTIR spectroscopy: A review | Tan Sook Ling, Syazwan Hanani Meriam Suhaimy, Nur Azimah Abd Samad Agricultural Journals
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