共查询到19条相似文献,搜索用时 609 毫秒
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氨基酸在薄层原位的傅里叶变换表面增强拉曼光谱 总被引:5,自引:0,他引:5
应用表面增强技术将薄层色谱与红外傅里叶变换拉曼光谱联用,在薄层色谱原位获得两种氨基酸光谱。研究表明,在薄层原位微量样品的NIR-FT-SERS光谱与纯固体样品FT-Raman光谱的主要特征谱带频率基本一致,在银微粒作用下,色氨酸分子中吲哚环环伸缩振动获最大增强,组氨酸分子中C=N双键的伸缩振动是明显增强,对8μg样品就能在薄层色谱原位较可靠地反映了分子的结构信息。 相似文献
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维生素B类药物在薄层原位的近红外付立叶变换表面增强拉曼光谱 总被引:3,自引:0,他引:3
维生素B类药物在薄层原位的近红外付立叶变换表面增强拉曼光谱汪瑗,于秉正张煦(首都师范大学分析测试中心北京100037)(北京大学分析测试中心北京)关键词维生素B_1,维生素B_2,薄层色谱,表面增强拉曼散射,近红外付立叶变换拉曼光谱将薄层色谱(TLC)... 相似文献
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采用高稳定、高灵敏的纳米金/多孔二氧化硅复合材料作为SERS基底,构建了一种二维薄层色谱-表面增强拉曼散射(TLC-SERS)联用方法,该技术结合了薄层色谱(TLC)的快速分离功能和SERS定性定量分析的优点,提高了分离能力。采用对巯基苯胺作为探针分子研究了基底的均匀性和批-批重复性。Mapping扫描实验表明,24个测量点峰强度的相对标准偏差(RSD)为5.9%,说明该基底具有良好的点-点重复性。9个批次基底信号值的RSD为7.5%。将该基底用于糖精钠的检测,线性范围为0.1~200 mg/L,检出限为0.06 mg/L。用于实际样品测定,检测出饮料中糖精钠为141 mg/L,水果中为18 mg/L,10 min内能完成分析测试。该方法灵敏度高,特异性强,前处理方式简单,实现了饮料及水果中糖精钠的快速检测。 相似文献
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1引 言薄层色谱(TLC)已广泛用于中药成分的分离与分析,但在薄层原位无法获得分离后各化合物的分子结构信息;表面增强拉曼光谱(SERS)可高灵敏度获得单一组分的分子振动光谱,将以上技术联用,可在混合物微量分离的原位获得化合物的分子结构信息,本文用TLC-SERS对洋金花注射液中莨菪烷型生物碱进行了探索。2 实验部分2.1 仪器与试剂FT-Raman910光谱仪(Nicollet公司),Nd:YVO4激光器,激光波长1064nm;三用紫外分析仪(上海分析仪器厂)。硅胶CF254(青岛海洋化工厂);… 相似文献
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由水杨醛衍生得到的Schiff碱由于其具有起因于受激分子内质子转移的光致 (热致 )变色性质而受到了人们的重视 .本文利用表面增强拉曼光谱研究了该类化合物在金、银基底及银溶胶表面上的拉曼光谱 ,比较了不同基底对吸附分子结构的影响 相似文献
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基于薄层色谱(TLC)与显微拉曼光谱(Micro-Raman spectroscopy)联用技术,对降压类保健食品中非法添加的3种化学成分(尼莫地平、拉西地平和尼群地平)进行原位富集检测,并对6种降压保健食品进行了测试.TLC法采用硅胶60F254铝合金薄层板为固定相,环己烷-乙酸乙酯(体积比5∶4)混合溶液为展开剂,在紫外灯(254 nm)下检视定位,使添加成分与保健食品基质进行初步分离;再对薄层板上微量添加成分斑点用丙酮原位富集,直接检测富集斑点的显微拉曼光谱,激光光源波长780 nm,显微镜倍数10倍,扫描范围100~3300 cm~(-1),激光功率24.0 m W,曝光时间0.05000 s,扫描30次.结果表明,常用降压类保健食品基质对添加成分检测结果无干扰,检出限为2~4μg.本方法准确、灵敏、简便、快速,为降压类保健食品中非法添加化学成分的快速检测提供了新的手段. 相似文献
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高效液相色谱-质谱联用分析洛伐他丁中的杂质 总被引:1,自引:0,他引:1
利用高效液相色谱-二极管阵列检测器-质谱联用方法对洛伐他丁及其杂质成分进行分离分析和结构鉴定。实验采用D iamonsil C18(5μm,4.6 mm×250 mm)为分离柱,乙腈-水(含0.1%乙酸)(65∶35)为流动相,分离并检测了洛伐他丁及其杂质;通过与DAD检测器和离子阱质谱联用,获得了它们的紫外光谱和质谱数据;紫外光谱表明除氢化洛伐他丁外其余杂质与洛伐他丁基本结构相同,利用MS和MS2数据确定了杂质的分子量和侧链结构,由此鉴定了其中10个杂质的结构。实验结果表明,高效液相色谱-二极管阵列检测器-质谱联用技术可以快速鉴定洛伐他丁中的杂质化学成分。 相似文献
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Andrej Oriňák Ivan Talian Evtim V. Efremov Freek Ariese Renata Oriáaková 《Chromatographia》2008,67(3-4):315-319
Hyphenation of thin layer chromatography (TLC) with surface-based spectral methods requires a homogeneous surface for direct
and quantitative analysis on the chromatographic plate after separation. Since most chromatographic materials do not produce
strong background signals in Raman spectroscopy (RS) or surface-enhanced RS (SERS), we tested the suitability of two different
chromatographic substrates and one interface for coupling SERS with TLC. This was carried out by using a chromatographic thin
layer, specially produced for RS measurements, and a monolithic silica thin layer. A typical TLC plate with a modified aluminium
backplate foil on one side was used as an interface. Three biologically active diterpenes, namely gibberellic acid (GA), abietic
acid (AA) and kaurenoic acid (KA), were used as test analytes. Stock solutions were applied directly onto the surface, followed
by the addition of silver colloid and measurements were taken by SERS. The strongest signal (excitation at 514.5 nm) was obtained
for GA using a Raman treated thin layer where the enhancement factor value was determined to be 102. Several fundamental Raman bands for GA were found at 1622, 1593, 1570, 1542, 1366 and 1236 cm−1. When the monolithic silica layer was used, no useful SERS signals were observed. The SERS spectra on modified aluminium
backplate for AA and GA were quite similar and no SERS spectrum was obtained for KA. Future research will be concerned towards
the use of nanostructured surfaces for SERS analysis.
An erratum to this article can be found at 相似文献
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Colloidal silver nanoparticles were prepared by reducing silver nitrate with sodium borohydride. The synthesized silver particles show an intense surface plasmon band in the visible region. The work reported here describes the interaction between nanoscale silver particles and various DNA bases (adenine, guanine, cytosine, and thymine), which are used as molecular linkers because of their biological significance. In colloidal solutions, the color of silver nanoparticles may range from red to purple to orange to blue, depending on the degree of aggregation as well as the orientation of the individual particles within the aggregates. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and absorption spectroscopy were used to characterize the assemblies. DNA base-induced differential silver nanoparticle aggregation was quantified from the peak separation (relates to color) of surface plasmon resonance spectroscopy (SPRS) and the signal intensity of surface-enhanced Raman scattering (SERS), which rationalize the extent of silver-nucleobase interactions. 相似文献
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Mattle Christian Heigl Nico Abel Gudrun Bonn Günther K. Huck Christian W. 《平面色谱法杂志一现代薄层色谱法》2010,23(5):348-352
JPC – Journal of Planar Chromatography – Modern TLC - By use of near infrared (NIR) spectroscopy hyphenated to thinlayer chromatography (TLC) for analysis of methoxylated flavones in a... 相似文献
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以聚丙烯酰胺(PAM)为模板,在液相中通过不同浓度的抗坏血酸还原硝酸银能够得到缠结的线状和树枝状银纳米结构.该方法合成条件温和(常温常压)、产率高、成本低、操作简单,并且得到了特殊形貌的缠结收光在谱一对起线的状线和状树银枝纳状米银结纳构.米通结过构透的射形电貌子和显性微质镜进(T行E了M)表,扫征描.研电究子表显明微,镜PA(SMEM对)线、拉形曼产光物谱的和形紫成外起?可了见决吸定性作用.在反应初期,大量新生成的银核被PAM链吸附,小颗粒逐渐长大,进而相连,导致生成了缠结的线状银纳米结构.另外,抗坏血酸的浓度越高,越不利于线状结构的生成.利用对巯基苯胺(PATP)为探针分子研究了银纳米结构的表面增强拉曼散射(SERS)活性,结果表明线状银纳米结构具有较强的表面增强拉曼散射效果. 相似文献
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以硝酸银为前驱物, 聚乙烯醇缩丁醛(PVB)为结构导向剂, 通过醇热法, 反应温度为140 ℃, 反应时间为24 h的条件下制备了银纳米线. 采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、热重分析(TG)、红外光谱(FT-IR)和激光拉曼光谱(Raman)等手段对产物进行了系统表征, 结果表明: 所得银纳米线具有面心立方结构, 沿着(111)晶面生长, 具有单晶结构; 考察了反应温度和时间对产物形貌的影响, 结果表明: 反应温度和时间在形成银纳米线的过程中起着关键的作用; 银纳米线具有较强的表面增强拉曼散射效应; 同时提出了银纳米线可能的晶化机理. 相似文献
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Nanostructured silver sulfide powder with an average particle size of about 45 nm, an acanthite α-Ag2S monoclinic structure (space group P21/c), and nonstoichiometric composition Ag1.93S has been synthesized by the chemical deposition method. The silver sulfide nanopowder has been studied by Raman spectroscopy. According to the Raman scattering data, heating the nanopowder with high-power laser radiation in air leads to photoinduced decomposition of the Ag1.93S nanopowder to give silver metal. The Raman spectrum of the silver sulfide nanopowder shows a series of bands in the low-frequency range from 90 to 260 cm–1 associated with vibrations of silver atoms, Ag–S bonds, and symmetric Ag–S–Ag longitudinal modes. Raman spectroscopy confirmed an acanthite monoclinic structure of synthesized silver sulfide nanopowder. 相似文献
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It is well-known that chemical functionalization of graphene has the great significance.We report the development of a new synthesis method of chloro-functionalized reduced graphene oxide(rGOCl).The rGOCl was prepared by radical reaction,and treatment of carboxyl graphene oxide(GOCOOH) with N-chlorosuccinimide(NCS) at 90℃ for 10 h under an atmosphere of nitrogen,using silver nitrate as catalyst.The morphologies and structures of the prepared materials were investigated by field-emission scanning electron microscopy(FESEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),Raman spectroscopy and the thermal gravimetric.Results indicated that the rGOCl can be readily obtained from graphene oxide(GO) in three steps. 相似文献
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介绍了常见签字笔的分类,并综述了近十年中签字笔油墨成分检测方法的研究进展,包括光谱法(拉曼光谱法、红外光谱法、显微分光光度法、紫外-可见导数光谱法),色谱法(薄层色谱法、气相色谱-质谱法、高效液相色谱法、高效毛细管电泳法、裂解气相色谱法)和综合分析法等(引用文献19篇)。 相似文献
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Surface Enhanced Raman Spectroscopy on Carbon Filaments 总被引:1,自引:0,他引:1
Norbert Meyer Klaus Nestler Lutz Engisch Andreas Heilmann Günter Marx 《Mikrochimica acta》2000,133(1-4):337-339
A method for analysis of carbon-containing thin films by using surface enhanced Raman spectroscopy (SERS) is described. Thin
films of boron nitride or silicon carbide which are deposited on carbon filaments were coated additionally with silver nanoparticles.
A very thin plasma polymer film was deposited on the silver particles to give a better long time stability. Using these layers,
very intensive carbon band were detected. 相似文献