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S. Shanmuga Sundara Raj Hoong‐Kun Fun Ji Wu Yu‐Peng Tian Fu‐Xin Xie Ze‐Huai Shao Sheng‐Li Li 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):1321-1322
The title compound, [Ni(C21H15N2S2)2], has a novel cis configuration with two fluorene moieties on the same side. The Ni atom is in a square‐planar configuration. The molecular packing is stabilized by intramolecular stacking between the fluorene moieties and extensive C—H?π interactions. 相似文献
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A simple and specific analytical method for the quantitative determination of shikimic acid from the methanol extract of the fruits of Illicium species and from various plant samples was developed. The LC–UV separation was achieved by reversed-phase chromatography on a C18 column with potassium dihydrogen phosphate and methanol as the mobile phase. In the LC–MS method, the separation was achieved by a C12 column using water and acetonitrile, both containing 0.1% acetic acid as the mobile phase. The methods were successfully used to study the percentage compositions of shikimic acid present in nine species of Illicium and various other plant samples. The detector response was linear with concentrations of shikimic acid in the range from 1.0–500.0 μg mL?1 by LC–UV and 100–1000 ng mL?1 by LC–MS. Mass spectrometry coupled with electrospray ionization interface is described for the identification of shikimic acid in various plant samples. This method involved the use of the [M-H]? ions of shikimic acid at m/z 173.0455 (calculated mass) in the negative ion mode with extractive ion monitoring. 相似文献
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Methods using liquid chromatography/mass spectrometry (LC/MS) and LC with diode array detection (DAD) in the UV range (LC/UV) were developed for the determination of low levels of the anthraquinones aloe-emodin and aloin-A (barbaloin) in aloe-based products. The methods were used to analyze several commercial products (liquids, semisolids, and solids) for the 2 anthraquinones. The wavelengths used for quantification of aloin-A, aloe-emodin, and emodin (internal standard) by DAD were 357, 257, and 289 nm, respectively. The on-column sensitivities were 0.25 and 0.05 ng by LC/UV and 0.01 and 0.025 ng by LC/MS for aloin-A and aloe-emodin, respectively. The methods are simple and sensitive and provide reproducible results; therefore, they are suitable for the determination of these anthraquinones in various aloe-based products. 相似文献
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