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901.
本文着重介绍使用高效液相色谱荧光测定天然食品中维生素B_1、B_2含量。在测试维生素B_1时,使用键合C_(18)分析柱,流动相为CH_3OH-0.01M KH_2PO_4 45/55,流速1.5ml/min,Ex:390nm,EM:470nm,柱温45℃;测维生素B_2时用强阳离子交换柱,流动相CH_3OH/0.01M KH_2PO_4,CH_3OH由30~70分钟梯度淋洗,流速1.5ml/min,柱温45℃,Ex:449nm,EM:530nm。在上述条件下所测部分食物中维生素B_1的回收率是92.51~101.85%,变异系数2.14~6.57%;维生素B_2的回收率为89.91~95.18%,变异系数0.19~6.19%。部分食物样品的测试结果令人满意。 相似文献
902.
LI Ming YAO Yi-Ming ZOU Jian-Zhong XU Zheng YOU Xiao-ZengCoordination Chemistry Institute Coordination Chemistry State Key Laboratory Nanjing University Nanjing Jiangsu China 《中国化学》1994,12(3):237-242
The synthesis spectroscopic properties and tautomerism of four novel mono-meso substituted(R)-octamethylporphyrins (R=o-hydroxybenzyl, p-aminobenzyl, 4-pyridinyl, and ferro-cenyl) were investigated. It was found that the porphyrins 2, 3 could be directly prepared in good yields via the coupling reaction of salicylaldehyde and p-aminobenzyl aldehyde with octamethyl-l',8'-dideoxy-ac-biladiene dihydrobromide, respectively. The free energy of activation (G) of the tautomerism of the porphyrins was calculated and interpreted in terms of electronic and steric nature. In contrast with 2-substituted-5,10,15,20-tetraphenylporphyrins, the substituents in meso position do not change the relative amount of two tautomers a and 6. 相似文献
903.
GAN ShengHua YANG Peng & YANG WanTai State Key Laboratory of Chemical Resource Engineering College of Materials Science Engineering Beijing University of Chemical Technology Beijing China 《中国科学:化学》2010,(1)
For plastic electronics and optics,the fabrication of smooth,transparent and stable crack-free inorganic oxide films(and patterning) on flexible polymeric substrates with strong bonding strength and controllable thickness from nanometers to micrometers is a key but still remains a challenge.Among versatile inorganic oxides,silica oxide film as SiOx is especially important because this semiconductor material could provide crucial properties in devices or serve as a base layer for further multilayer construct... 相似文献
904.
PAN QiYu WANG ShaoZhong LU JinJian MENG LingHua & YAO ZhuJun Nanjing National Laboratory of Microstructures School of Chemistry Chemical Engineering Nanjing University Nanjing China Joint Laboratory of Green Chemistry 《中国科学:化学》2010,(1)
Unique endoperoxide moiety of artemisinin and its derivatives has been considered the functionality exhibiting highly potent antimalarial and anticancer activities.To investigate the mechanisms of their biological actions,development of suitable molecular probes including biotinylated derivatives is of extreme significance.The synthesis and preliminary biological assessment of four new biotinylated artemisinin derivatives have been reported in this work. 相似文献
905.
Hui Jing Zhang Yong Gang Hu Yong Qian Wanga Jie Zhangc a School of Environmental Science Engineering Huazhong University of Science Technology Wuhan China b State Key Laboratory of Agricultural Microbiology College of Life Science Technology Huazhong Agricultural University Wuhan China c College of Environmental Science & Technology Huangshi Institute of Technology Huangshi China 《中国化学快报》2010,(8)
<正>The possibility of direct analytical applications of ferrate(Ⅵ) solution,which was freshly electrogenerated in low-concentration NaOH electrolyte,was studied by a flow-injection-chemiluminescence(FI-CL) system.It was found that some inorganic ions, organic molecule and biomolecule could enhance the chemiluminescence emission caused by ferrate(Ⅵ)-luminol reaction.V(Ⅴ), Ca(Ⅱ),Mg(Ⅱ),phloroglucinol,and bovine hemoglobin(Hb) chosen as samples were successfully detected by this developed method.The analytical characteristics of the system for the analytes determination including linear ranges,correlation coefficients, limits of detection combined with FI analysis were studied. 相似文献
906.
LU XiaoMei FAN QuLi ZHANG GuangWei PU KanYi & HUANG Wei Jiangsu Key Laboratory for Organic Electronics & Information Displays the Institute of Advanced Materials Nanjing University of Posts & Telecommunications Nanjing China 《中国科学:化学》2010,(5)
Water-soluble light-emitting nanoparticles were prepared from hydroxyl group functionalized oligos(p-phenyleneethynylene) (OHOPEL) and water-soluble polymers(PEG,PAA,and PG) by non-covalent bond self-assembly.Their structure and optoelectronic properties were investigated through dynamic light scattering(DLS) ,UV and PL spectroscopy.The optical properties of OHOPEL-based water-soluble nanoparticles exhibited the same properties as that found in OHOPEL films,indicating the existence of interchain-aggregation... 相似文献
907.
ZHU Jun WANG FangJun DONG XiaoLi YE MingLiang & ZOU HanFa Key Laboratory of Separation Sciences for Analytical Chemistry National Chromatographic Research Analysis Center Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China 《中国科学:化学》2010,(4)
Peptidomics draws more and more attention in discovering useful biomarkers for early diagnosis of disease. However, there is lack of efficient quantification strategy in peptidome analysis. In this study, a strategy with label-free quantification of the targeted endogenous peptides based on peak intensity using μUPLC-Q-TOF-MS/MS was developed for quantitative peptidome analysis of human serum. Different amounts of standard BSA tryptic digesting peptides were added into the same serum extracts for evaluation... 相似文献
908.
ZHAI Shuo HONG HaiYan ZHOU YongFeng & YAN DeYue State Key Laboratory of Metal Matrix Composites College of Chemistry Chemical Engineering Shanghai Jiao Tong University Shanghai China 《中国科学:化学》2010,(5)
A novel hyperbranched multiarm copolymer of HBPO-star-PDEAEMA with a hydrophobic poly(3-ethyl-3-(hydroxymethyl) oxetane)(HBPO) core and many cationic poly(2-(N,N-diethylamino) ethyl methacrylate)(PDEAEMA) arms has been synthesized through an atom transfer radical polymerization(ATRP) method,and been applied to spontaneously reduce and stabilize gold nanoparticles(AuNPs) in water without other additional agents.The size of the nanoparticles could be effectively controlled at about 4 nm,and the nanoparticles ... 相似文献
909.
GUO Tianying HAO Guangjie SONG Moudao ZHANG Banghua Institute of Polymer Chemistry State Key Laboratory of Functional Polymer Materials for Adsorption Separation Nankai University Tianjin China 《Chinese Journal of Reactive Polymers》2002,(1)
1. INTRODUCTION The blending of polymers is an economically viable and versatile way in which new materials can be produced to have a wide range of properties. The majority of polymers are immiscible at the molecular level as given by laws of thermodynami… 相似文献
910.
Spin-lattice relaxation time, spin-spin relaxation time and two-dimensional nuclear Overhauser enhancement spectroscopy (2D NOESY) experiments of polyoxyethylene lauryl ether (Brij-35) micelles in aqueous solutions at a concentration of 100 times the critical micellar concentration (cmc) give direct evidence that the hydrophilic polyoxyethylene chains, staying in the exterior of the micellar core, are coiled, bent and aligned around the micellar core with a certain number of water molecules included. This hydrophilic layer is in contact with the solvent, water, keeping the micellar solution stable. 1H NMR relaxation time measurements show that the first oxyethylene group next to the alkyl chain participates in the formation of the surface area of the micellar core. The motion of the hydrophilic polyoxyethylene chains is less restricted as compared with the hy-drophobic alkyl chains. 相似文献