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1.
蒋治良  彭忠利  刘绍璞 《中国化学》2002,20(12):1566-1572
Proteindeterminationisveryimportanttobiochem istryandbioanalyticalchemistry ,andananalyticalitemofqualitycontrolsintheseparationorpurificationofbio logicalandchemicalpharmaceuticalsandthatoffoodex amination .Comparedwithcommonspectrophotometricmethodsuc…  相似文献   

2.
Experimental data on liquid noble-metal-based alloys were analysed in terms of a pseudopotential approach. The anomalies in the heat of mixing, the electrical resistivity and the magnetic susceptibility were found to be reflected by the theory in a qualitative manner even if compound formation or short range order is not taken into account. The emphasis was placed on liquid Ag-In, but other examples of this particular class of alloys were also included in the discussion.  相似文献   

3.
在pH 9.5的NH3-NH4C l缓冲溶液中,汞(Ⅱ)与双硫腙可形成能稳定存在的螯合物微粒,显示出共振散射效应。该微粒体系的最强共振散射峰在560 nm处,汞(Ⅱ)的质量浓度在0.028~6.140μg/mL范围内,共振散射与△I之间存在良好的线性关系,回归方程为△I=76.786ρ+2.7,相关系数为0.999 8,检出限0.012μg/mL Hg。利用共振散射测量水样中微量汞(Ⅱ),方法简单、灵敏度高、结果满意。  相似文献   

4.
痕量新霉素的共振散射光谱分析   总被引:1,自引:0,他引:1  
在pH值5.9 NaAc-HAc缓冲介质中,十二烷基苯磺酸钠与新霉素相互作用形成粒径约为160±12 nm的缔合微粒,在320、340、420、470 nm有4个共振散射峰.新霉素浓度在0.076~6.840μg/mL范围内与470 nm处的共振散射强度成正比,检出限为0.03μg/mL.该法具有选择性较好、灵敏度较高、快速、简便等特点,用于市售滴耳液和尿液分析,结果满意.  相似文献   

5.
纳米金共振散光谱探针测定钼   总被引:1,自引:1,他引:0  
在0.45mol/L硫酸-0.026mol/L硫脲-0.32mol/LKSCN介质中,粒径为70nm的纳米金的共振散射信号较弱,Mo(Ⅵ)被硫脲还原为Mo(Ⅴ),Mo(Ⅴ)与硫氰酸钾生成橙红色配合物[MoO(SCN)s]^2-.该配合物与纳米金探针作用,导致402和554nm共振散射峰增强.钼浓度在1.O~20×10^-6mol/L范围内与402nm波长的共振散射光强度成线性关系,方法的检出限为5.1×10^-7 mol/L Mo.该法用于废水中钼的测定,结果满意.  相似文献   

6.
李文戈  潘兆瑞  王作为 《合成化学》2007,15(5):602-604,646
3-(3-吡啶基)丙烯酸(3-HPYA)配体与过渡金属离子铅通过水热法合成了一种新的三维配位聚合物[Pb(3-HPYA)2]n(1),其结构经IR,元素分析和X-射线单晶衍射仪表征.1属于单斜晶系,空间群P2/c,晶胞参数:a=1.032 3(3)nm,b=1.6944(5)nm,c=0.864 9(3)nm,β=93.939(5)°,Z=1.509 2(8)nm3,Z=4,Mr=490.73,Dc=2.216 g·cm-3,F(000)=9444,μ=11.200.  相似文献   

7.
液相卤化银纳米微粒的界面荧光和共振散射光谱特性   总被引:4,自引:0,他引:4  
蒋治良  翟好英  章表明  刘庆业  李廷盛 《化学学报》2004,62(14):1272-1276,J001
液相卤化银纳米微粒的共振散射光谱和发射光谱表明,AgCl和AgBr纳米微粒均在330,400,470和680nm处产生4个共振散射峰,在340,400和470nm处产生三个荧光峰.Ad纳米微粒在340,400,437,470和680nm处产生5个共振散射峰;除在340,400和470nm处产生3个荧光峰外,在434nm处有一最强的荧光峰.卤化银纳米微粒体系的浓度对共振散射信号的影响与浓度对荧光强度的影响一致,Aga,AgBr和AgI体系的共振散射光信号强度分别约为荧光信号的110,130和80倍,即荧光与共振散射之间存在相关性.提出了液相AgX纳米微粒荧光产生机理,解释了荧光与共振散射之间存在相关性的原因.  相似文献   

8.
Systematic studies in the quaternary system Na/Ge/Sb/Te yielded the new compound Na9Sb[Ge2Te6]2. Its crystal structure is isotypic to Na9Sb[Ge2Se6]2 (space group C2/c with a = 9.541(2), b = 26.253(7), c = 7.5820(18) Å and β = 122.233(15)°, Z = 2). The structure is characterized by Ge–Ge dumbbells that are octahedrally coordinated by Te, forming ethane‐like [Ge2Te6]6– anions. Cation sites are occupied by Na+ as well as shared by Na+ and Sb3+. Na9Sb[Ge2Te6]2 is formally obtained from the reaction of one equivalent Na8[Ge4Te10] and one equivalent NaSbTe2. In contrast to members of the metastable solid solution series (NaSbTe2)1–x(GeTe)x, Na9Sb[Ge2Te6]2 is a thermodynamically stable compound. It is a semiconductor with a bandgap of 1.51 eV.  相似文献   

9.
The interaction of cryptand[222] with amino acids in water, which is weak for most amino acids and controlled by the solvent effect in the case of non-polar amino acids, was studied at 298.15 K by the calorimetric method. Cryptand[222] undergoes selective complex formation with some polar and aromatic amino acids. The thermodynamic functions and equilibrium constants of complex formation of the macrocyclic ligand withl-histidine,l-threonine, andl-glutamine were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2285–2288, December, 1999.  相似文献   

10.
A novel complex [Na(NIT-1'-MeBzIm)3]ClO4 (NIT-1'-MeBzIm = 2-{2'-[(1'- methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) has been prepared and structurally characterized by elemental analysis, IR spectra and X-ray diffraction methods. The title complex crystallizes in trigonal, space group P3 and Z = 2. Crystal data: C45H57ClN12NaO10, Mr = 984.47, a = 13.9411(8), b = 13.9411(8), c = 14.8622(16) A, γ= 120°, V= 2501.5(3) A^3, Dc = 1.307 g/cm^3, μ(MoKα) = 0.152 mm^-1, F(000) = 1038, R = 0.0637 and wR = 0.1813 for 1957 observed reflections with I 〉 2σ(I). X-ray analysis reveals that the Na(I) ion is six-coordinated with three NIT-1'-MeBzlm radicals. As we know, three radicals coordinating to the Na(I) ion in the main group by a chelate way is the first example. The Na(I) ion resides in a distorted octahedron with a facial configuration. Meanwhile, the intermolecular weak interactions result in a 2-D double layer conformation where the uncoordinated perchlorate anions are inserted in the packing space and take part in the H-bond interactions, and each complex is connected with six neighboring complexes and three perchlorate anions.  相似文献   

11.
A simple way to prepare cucurbit[5]uril is described. The macrocycles of the cucurbituril type are nearly insoluble in water. The solubilities of cucurbit[5]uril, decamethylcucurbit[5]uril and cucurbit[6]uril in hydrochloric acid, formic acid and acetic acid of different concentrations have been investigated. Due to the formation of complexes between cucurbit[n]urils and protons the solubility increases in aqueous acids. The macrocyclic ligands are able to form complexes with several organic compounds. Thus, the complex formation of the cucurbituril macrocycles with different amines has beenstudied by means of calorimetric titrations. The reaction enthalpy gives noevidence of the formation of inclusion or exclusion complexes. 1H-NMR measurements show that in the case of cucurbit[5]uril and cucurbit[6]uril the organic guest compound is included within the hydrophobic cavity. Decamethylcucurbit[5]uril forms only exclusion complexes with organicamines. This was confirmed by the crystal structure of the decamethylcucurbit[5]uril-1,6-diaminohexane complex.  相似文献   

12.
在pH值为2.5~4.0的BR缓冲溶液介质中,牛血清白蛋白(BSA)、糜蛋白酶(Chy)和α-淀粉酶(α-Amy)等蛋白质与酸性多糖硫酸软骨素A(CS)形成结合物。 此时将会使共振瑞利散射(RRS)和二级散射(SOS)、倍频散射(FDS)等共振非线性散射的强度显著增大。 在蛋白质过量时,3种散射增强(ΔIRRS、ΔISOS和ΔIFDS)均在一定范围内与CS的浓度成正比,方法具有高灵敏度。 当用Chy、BSA和α-Amy作探针时,3种散射法对于CS的检出限分别在1.4~5.8 μg/L、2.0~13.2 μg/L和1.8~9.6 μg/L。 其中以Chy-CS体系的RRS法最灵敏(检出限1.4 μg/L),可用于痕量CS的测定。 研究了反应体系的RRS、SOS和FDS的光谱特征、适宜的反应条件和影响因素,并以Chy-CS体系为例考察了共存物质的影响,方法有良好的选择性,将其用于滴眼液中CS的测定,取得了较好的结果。  相似文献   

13.
《Analytical letters》2012,45(9):1380-1395
A novel resonance Rayleigh scattering (RRS) detection approach combined with high–performance liquid chromatography (HPLC) was developed for the determination of reserpine, deserpidine, and ajmalicine. The resonance Rayleigh scattering signal increased when the analytes were bound to diiodofluorescein in Britton–Robinson buffer (pH 4.2). Separation was performed using a C18 column with a mobile phase consisting of acetonitrile–5 millimolar ammonium acetate buffer at pH 4.2 (44:56, volume by volume). Resonance Rayleigh scattering was measured at excitation and emission wavelengths of 320 nanometers. The experimental parameters affecting the separation and the scattering intensity were carefully optimized. Possible mechanisms for the resonance Rayleigh scattering enhancement of the indole alkaloid–diiodofluorescein system were explored by scanning electron microscopy, nuclear magnetic resonance, and ultraviolet-visible absorption spectroscopy. The method was employed for the determination of the analytes in human urine and pharmaceutical tablets.  相似文献   

14.
范莉  刘绍璞  杨大成  胡小莉 《中国化学》2002,20(12):1552-1556
IntroductionInrecentyears ,resonanceRayleighscattering(RRS)methodasanewanalyticaltechniquehasbeenextensivelystudiedandwidelyusedtothedeterminationofsomebiologicalmacromolecules ,suchasnucleicacid ,1 4 protein5 8andheparin ,9aswellasinorganicion ,10 14 duetoitssi…  相似文献   

15.
Single phase powders of (A19N7)[In4]2 (A = Ca, Sr) and (Ca4N)[In2] were prepared by reaction of melt beads of the metallic components with nitrogen. The crystal structure of (Ca19N7)[In4]2 was refined based on neutron and X‐ray powder diffraction data. The crystal structure of (Sr19N7)[In4]2 was solved from the X‐ray powder pattern. The structure refinements in combination with results from chemical analyses ascertain the compositions. The compounds (A19N7)[In4]2 (A = Ca, Sr) are isotypes of (Ca19N7)[Ag4]2; (Ca19N7)[In4]2 is probably identical to the earlier reported (Ca18.5N7)[In4]2. The crystal structure of the isotypes (A19N7)[In4]2 (A = Ca, Sr; cubic, , Ca: a = 1471.65(3) pm; Sr: a = 1561.0(1) pm) contains isolated [In4] tetrahedra embedded in a framework of edge‐ and vertex‐sharing (A6N) octahedra. Six of these octahedra are condensed by edge‐sharing around one central A2+ ion to form “superoctahedra” (A19N6) which are connected three‐dimensionally via further octahedra by corner‐sharing. The crystal structure of (Ca4N)[In2] (tetragonal, I41/amd, a = 491.14(4) pm, c = 2907.7(3) pm) consists of alternating layers of perovskite type slabs of vertex‐sharing octahedra (Ca2Ca4/2N) and parallel arranged infinite zigzag chains equation/tex2gif-stack-1.gif[In2]. In the sense of Zintl‐type counting the compounds (A2+)19(N3?)7[(In2.125?)4]2 present an electron excess, (Ca2+)4(N3?)[(In2.5?)2] is electron deficient. Metallic properties are supported by electrical resistivity and magnetic susceptibility measurements. The analysis of the electronic structures gives evidence for the existence of homoatomic interactions In–In and significant heteroatomic metal–metal interactions Ca–In which favor the deviations of the title compounds from the (8 – N) rule.  相似文献   

16.
The complex formation between cucurbit[5]uril, decamethylcucurbit[5]uril and cucurbit[6]uril and alkali, alkaline earth and ammonium cations is examined. The solubility of these ligands is rather small in aqueous solution. In the presence of salts the solubility normally increases due to the formation of complexes. The total concentration of the ligands can be easily measured from the total organic carbon content of the salt solutions saturated with the ligand. From these results it is possible to calculate the stability constants of the complexes formed even without the knowledge of the exact solubility of the ligand.  相似文献   

17.
在pH9.0的NH3—NH3-Cl缓冲溶液中,Zn(Ⅱ)与双硫腙可形成能稳定存在的螯合物微粒,显示出共振散射效应.该微粒体系的最强共振散射峰在605nm处,锌的浓度在0.02~1.54μg/mL范围内与共振散射强度(J605nm)呈线性关系,检出限为0.008μg/mL Zn.利用共振散射测量微肥中微量元素锌,方法简单、灵敏度高、重现性好,结果满意。  相似文献   

18.
刘健  刘忠芳  胡小莉  孔玲  刘绍璞 《化学学报》2010,68(12):1210-1216
在pH 1.8~2.5的Britton-Robinson (BR)缓冲介质中, 硫酸软骨素A (CSA)的硫酸酯基离解而以带多个负电荷的大阴离子存在, 而人血清白蛋白(HSA)、牛血清白蛋白(BSA)、糜蛋白酶(Chy)、溶菌酶(Lyso)和α-淀粉酶(α-Amy)等蛋白质处于其等电点(pI)之下, 则是带多个正电荷的大阳离子, 两者可借静电引力、氢键作用、疏水作用而结合形成复合物. 此时将引起共振瑞利散射(RRS)和二级散射(SOS)、倍频散射(FDS)等共振非线性散射(RNLS)的显著增强并出现新的散射光谱. 3种散射的散射增强(ΔIRRS, ΔISOS和ΔIFDS)均在一定范围内与蛋白质的浓度成正比, 方法具有高灵敏度. 三种方法对蛋白质的检出限分别为4.5~12.0 (g/L (RRS法)、8.9~15.8 (g/L (SOS法)和13.4~31.5 (g/L (FDS法), 其中以CSA-BSA体系灵敏度最高(检出限可达4.5 (g/L). 研究了反应体系的RRS, SOS和FDS的光谱特征、适宜的反应条件和影响因素, 讨论了反应机理、结合模式以及散射增强的原因. 并以CSA-BSA体系为例考察了共存物质的影响, 表明方法有良好的选择性. 方法可用于正常人血清及尿样中蛋白质的测定.  相似文献   

19.
利用核磁共振(NMR)技术研究了瓜环[n](n=7,8)对外消旋盐酸哌甲酯的手性识别。研究结果显示,盐酸哌甲酯对映异构体与瓜环形成包合物后,其质子的化学位移移动方向和幅度不同。同时,手性碳附近的某些原子所对应的吸收峰裂分为两组信号,这两组信号分别对应盐酸哌甲酯的两个对映体。说明两个对映体与瓜环形成了作用模式不同的超分子包结物,从而使对映体能够区分开来,即非手性的瓜环将手性盐酸哌甲酯区别开来,实现了瓜环对苏式哌甲酯两个对映体的快速手性识别。  相似文献   

20.
在pH 7.0的磷酸盐缓冲溶液中,氯金酸被3,5-二羟基苯甲酸(DBA)还原生成的金纳米粒子在610nm处产生一个较强的共振散射峰;当有三聚氰胺(MA)存在时,DBA与MA形成多氢键化合物而不能还原氯金酸,导致610 nm处共振散射峰的强度降低.三聚氰胺的浓度在5.0×10 -6~4.0×10-5 mol·L-1范围内...  相似文献   

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