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研究了以达旦黄(TY)作为共振光散射探针测定市售药品中丁胺卡那霉素(AMK)的测定方法.该方法基于在pH=5.5的Britton—Robinson缓冲溶液中,达旦黄和丁胺卡那霉素结合后有强烈的共振光散射作用.在λ=482nm处,共振光散射强度(△IRLS)最大且光散射的强度与AMK的浓度在0.4~2.4mg·L^-1范围内成正比(相关系数r=0.9986),检出限为8.6×10^-3mg·L^-1.该方法简便、快速、灵敏,对1.0mg·L^-1的AMK溶液平行测定11次,RSD=2.57%.用于市售样品的分析测定,结果满意。 相似文献
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在碱性条件下,Ni(Ⅱ)和1-(2-吡啶偶氮)-2-萘酚(PAN)形成聚合物,对PAN的共振光散射有增强作用,加入十二烷基苯磺酸钠(SDBS)进一步敏化该体系。共振光散射增强强度(ΔI)与Ni(Ⅱ)浓度呈良好的线性关系,据此建立了测定Ni(Ⅱ)的共振光散射分析方法。在优化的实验条件下,体系的最大散射波长位于545 nm处,方法的线性回归方程为ΔIRLS=4502.9ρ(μg/mL) 271.82;线性范围为15.2~500 ng/mL;相关系数γ=0.9975;检出限为4.57 ng/mL。对Ni(Ⅱ)分别为50、200、400 ng/mL低、中、高3个浓度进行11次平行测定,其相对标准偏差分别为:3.5%、3.0%和1.7%。 相似文献
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研究了一种苯并噻唑阳离子花菁与脱氧核糖核酸(DNA)作用的共振光散射光谱,在pH 6.0的六次甲基四胺-HCl缓冲介质中,痕量DNA的加入使花菁在590nm的共振光散射强度显著增强。在最佳实验条件下,增强的共振光散射强度与DNA浓度具有良好的线性关系,据此建立了一种测定DNA的共振光散射光谱法。方法的线性范围为:小牛胸腺DNA(CT DNA),0~20μg/mL,鱼精子DNA(FS DNA),0~15μg/mL;检出限分别为0.005μg/mL和0.008μg/mL。该方法已用于合成样品中DNA的测定。 相似文献
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研究了Co2 与1-(2-噻唑偶氮)-2-萘酚(TAN)、十二烷基苯磺酸钠(SD-BS)作用的共振瑞利散射光谱,在pH 8.0的BR缓冲溶液中,Co2 的加入导致体系共振光散射的增强,其增强强度与Co2 的质量浓度呈线性关系,据此建立了一种测定Co2 的共振光散射法。该法的线性范围为0~600 ng/mL,相关系数为r=0.9990,检出限为2.25 ng/mL。将该法用于人发、茶叶、维生素B12中Co2 的测定,加标回收率为99.83%~105.4%。 相似文献
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利用生命周期评价软件Sima Pro7和环境影响评价模型IMPACT 2002+,通过对化学分析方法的清单分析及计算,评价和比较了3种测定铁矿中全铁含量的化学分析方法(酸溶法、碱熔法、微波消解法)对人类健康、生态质量、气候变化及资源消耗等的影响。发现3个方法对环境的影响主要集中于人类健康危害、气候变化和资源消耗方面。通过计算3种方法的生命周期单一环境负荷值,发现碱熔法、酸溶法和微波消解法的单一环境负荷值分别为1.97,1.81,0.07 m Pt,对环境总体的影响,碱熔法和酸溶法分别为微波消解法的28倍和26倍。单独对人类健康危害指标而言,碱熔法为1.15 m Pt,酸溶法为1.07 m Pt,微波消解法仅为0.039 6 m Pt。碱熔法、酸溶法和微波消解法的碳足迹分别为5.12,4.62,0.189 kg CO_2eq。说明微波消解法排放量最小,其环境友好性最佳,值得推荐。 相似文献
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In this paper,the response factors of thermal conductivity detector(TCD) of monochloromethane and dimethyl ether are estimated and calculated by using group cross section area method,molecular diameter method and homologue linear rule method. These methods are compared and applied to the analysis of industrial monochloromethane. For dimethyl ether,TCD's response factor estimated using homologue linear rule method is near to that using group cross section area method. 相似文献
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Oleg Lebedev 《Tetrahedron》2009,65(27):5438-1016
A novel method for the synthesis of cyclic hydrazine derivatives is reported. The new method for the generation of nitrogen-containing heterocycles is based on a polyanion strategy. The described method provides a convenient access to cyclic hydrazine derivatives, which are extensively used in drug industry and agriculture. The advantages and limitations of the new method are also demonstrated. 相似文献
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Inverse gas chromatography (IGC) is an important technique for the characterization of surface properties of solid materials. A standard method of surface characterization is that the surface dispersive free energy of the solid stationary phase is firstly determined by using a series of linear alkane liquids as molecular probes, and then the acid-base parameters are calculated from the dispersive parameters. However, for the calculation of surface dispersive free energy, generally, two different methods are used, which are Dorris-Gray method and Schultz method. In this paper, the results calculated from Dorris-Gray method and Schultz method are compared through calculating their ratio with their basic equations and parameters. It can be concluded that the dispersive parameters calculated with Dorris-Gray method will always be larger than the data calculated with Schultz method. When the measuring temperature increases, the ratio increases large. Compared with the parameters in solvents handbook, it seems that the traditional surface free energy parameters of n-alkanes listed in the papers using Schultz method are not enough accurate, which can be proved with a published IGC experimental result. 相似文献
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Two different approaches, the rectangular pulse method and a new method, the frontal velocity analysis method are applied to the determination of competitive isotherms for two systems on ODS-silica. Both sets of experimental data are found to fit well to the competitive-Langmuir isotherm equation. The data obtained from the rectangular pulse method and the frontal velocity analysis method are in general agreement with each other and the best coefficients of the competitive isotherms obtained with the two methods are close. This shows that the simpler and easier method, the frontal velocity analysis method can be used to determine binary competitive isotherms. 相似文献
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蔗糖酯的合成研究进展 总被引:2,自引:0,他引:2
综述了蔗糖酯的合成方法及工艺的研究进展,并对其反应机理进行了阐述.蔗糖酯的合成方法主要有四种:溶剂法、微乳化法、无溶剂法以及酶催化法.溶剂法采用DMF或DMSO为溶剂,但是这两种溶剂均有毒,限制了蔗糖酯在食品等行业的应用.微乳化法采用丙二醇或水代替溶剂法所使用的有毒溶剂,并加入乳化剂,使反应体系近似为均相体系.无溶剂法则是通过在反应体系中加入乳化剂或表面活性剂等使熔融相成均一相,反应平稳.但是一般无溶剂法反应温度较高,反应不易进行,产率低,且产品质量得不到保证.酶催化合成法是一种新的生物合成方法,采用生物酶代替传统的催化剂合成蔗糖酯,该法催化活性高、反应条件温和、选择性强、产物易分离等优点.文中还对蔗糖酯粗品的纯化工艺进行了介绍. 相似文献
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M.G. Marmorino 《Journal of mathematical chemistry》2002,31(2):197-203
Two lower bound methods are compared: the inverse method and a generalized variance method. As the generalized variance method is a generalization of the simple method of variance, the inverse method is shown to be a generalization of the Temple formula. We show that for the same a priori information and basis set, the generalized variance and inverse methods are equivalent. 相似文献
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预测烷烃密度的新方法: 基团键贡献法 总被引:29,自引:0,他引:29
根据分子结构的特点,通过用染色矩阵和邻接矩阵对分子结构进行矩阵化表征,发展了一种根据分子结构信息烷烃密度的新方法---基团键贡献法。该方法有机地将基团贡献法和化学键贡献法结合在一起,既考虑了分子中基团的特性,又考虑了基团之间的连接性(化学键),具有基团贡献法和化学键贡献法的特点。对658种烷烃的计算结果表明,密度预测值十分接近实验值,平均误差0.245%,进一步外推对聚乙烯、聚丙烯和聚1-丁烯等聚合物的密度进行预测,也取得了令人满意的结果。 相似文献