压缩X因子导数光谱法测定痕量锗

本采用压缩Ｘ因子导数光谱技术实现了宽峰体系灵敏度的大幅度提高，提出了测定痕量锗的方法。在０．７２ｍｏｌ／ＬＨ２ＳＯ４和３．０ｍｏｌ／ＬＨ３ＰＯ４的混酸介质中，锗－水杨基荧光酮－ＯＰ三元显色体系的压缩Ｘ因子四阶导数光谱摩尔响应系数达１．８９×１０＾６Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，灵敏度比常规光度法高１２．４倍；最低检测出限为０．０００３３ｍｇ／Ｌ，比常规光谱法低４倍；选择性也进一步提高，绝大多数离     

偶氮胭脂红B与血清蛋白质相互作用的光度法研究及其分析应用

在酸性介质中，偶氮胭脂红B（ABX）与蛋白质在室温下能迅速结合生成复合物，其最大吸收波长为570nm，比ABX红移了50nm。本文用光度法研究了该结合反应的最佳条件，并在此基础上建立了一个测定蛋白质的新方法。在570nm处各蛋白质的浓度至少在2.5～120mg/L范围内与吸光度成正比，对测定牛血清蛋白质（BSA）、人血清蛋白（HSA）及γ-球蛋白（IgG）的桑德尔灵敏度分别为0.173、0.173和0.199μg/cm^2。除阴阳离子表面活性剂外，基余大部分物质不干扰蛋白质的测定。可见方法具有选择性好、灵敏度高且快速、稳定的优点，用于尿液及人血清样品中总蛋白的测定，所得结果与考马斯亮蓝方法测得结果基本一致。     

Highly sensitive spectrophotometric determination of trace amounts of platinum(IV) with the molybdate-basic dyes-poly(vinyl alcohol) system

Three highly sensitive spectrophotometric methods for the determination of platinum(IV) have been developed, based on its colour reactions with molybdate and basic dyes (BD) in aqueous solution in the presence of poly(vinyl alcohol). Platinum(IV) reacts with molybdate and BD to form ion — association complexes of composition (BD)₂[Pt (MoO₄)₃]. The molar absorptivities are between 6.83 × 10⁵ and 9.51 × 10⁵ dm³mol^–1cm^–1, the highest value being found with nile blue. Suitable conditions for the reactions and the effects of foreign ions were investigated. The methods can be applied to the spectrophotometric determination of trace amounts of platinum(IV) in some catalysts and ores.     

利用电荷迁移反应测定头孢羟氨苄

提出一种基于电荷迁移反应简便可靠地测定头孢羟氨苄的分光光度法。在甲醇－乙醇介质中，头孢羟氨苄与氯冉酸于５０℃反应１５ｍｉｎ能够形成稳定的１：１络合物，其λｍａｘ＝５２８ｎｍ，线性范围为２０￣４００ｍｇ／Ｌ。用拟定的方法测定原粉和胶囊，结果与药典法一致。对浓度１００ｍｇ／Ｌ的药物１０次测定相对标准偏差为１．４％，样品的标准加入回收率为９９．０％￣１００．８％。     

Spectroscopic Study of the Complexation of DDQ with 1,10-Diaza-18-crown-6 in Chloroform Solution

The formation of charge transfer complexes with 1:1 and 2:1 stoichiometries (acceptor-to-donor) between DDQ and 1,10-diaza-18-crown-6 in chloroform solution was investigated spectrophotometrically. The stepwise formation constants of the resulting complexes were evaluated from the non-linear least-squaresfitting of the absorbance-mole ratio data. The enthalpies and entropiesof the complexation reactions were determined from the temperature dependence of the stepwise formation constants. The resulting 1:1 and 2:1 complexes were isolated in crystalline form and characterized. The results are consistent with the ionic structure of the resulting charge transfer complexes.     

衍生荧光法测定盐酸西布曲明

通过衍生反应，建立了用荧光光度法测定盐酸西布曲明的新方法。并对衍生体系、反应条件、产物稳定性等进行了研究。实验确定丙二酸和乙酸酐混合试剂与盐酸西布曲明在75℃的水浴中加热15min，所得产物发射强荧光，最大激发波长λcx=456nm，最大发射波长λem=496nm。在上述波长下，荧光强度与盐酸西布曲明的质量浓度在0．11～9．5μg／mL范围内呈良好的线性关系，检出限为13．4ng／mL，标准加入回收率在95．4％～104．2％。用于曲美胶囊中盐酸西布曲明的测定。     

锇(Ⅳ)-高碘酸钾-偶氮氯膦-pC催化分光光度法测定痕量锇的研究

在1．0mol／L硫酸介质中，微量锇(IV)的存在对KIO4氧化偶氮氯膦-pC的褪色反应有明显的催化作用，据此建立微量锇的催化光度分析法、方法的检出限为0．0002μg／mL，锇(IV)的含量在0．0006—0．003μg/mL之间有良好的线性关系，反应在水相中进行，应用于贵金属精矿中锇的测定，结果满意．     

水杨基荧光酮—过氧化氢催化动力学光度法测定痕量锇（Ⅳ）

在碱性介质中，痕量锇（Ⅳ）对水杨基荧光酮（ＳＡＦ）与过氧化氢的氧化还原反应有显著的催化作用。本文以此为基础，提出用分光光度催化动力学测定痕量锇（Ⅳ）的新方法。本法未加掩蔽剂时的线性范围是０．０８－０．８０μｇ／Ｌ，加入掩蔽剂后的线性范围是０．０８－０．８０μｇ／Ｌ，检出限为０．０８μｇ／Ｌ。本法用于实际样品中Ｏｓ（Ⅳ）的测定，结果良好，本实验还测定了此催伦反应的活化能和反应级数。     

Low detection limit spectrophotometry

An efficient, more sensitive and accurate spectrophotometric process is possible and can be used to obtain qualitative or quantitative results for analytes at limiting concentrations lower than usual. Transmission measurements (incident light power, P₀, or transmitted, P) are performed with a fluorescence spectrometer. One cell only is used to measure standards or unknown solutions, placed between the standard holder cuvette and the emission monochromator of the instrument. The source of the radiant power (P₀) is not the xenon lamp but the fluorescence or scattered radiation from the holder cuvette filled with an appropriate solution. The analyte concentration is found from a calibration graph, based upon Beer’s law or the approximate formula P₀−P=2.303P₀εbc, which is valid for dilute solutions. Determination of iron in a reference material, using 1,10-phenanthroline as the chromogenic reagent, was chosen as an example to demonstrate the suitability of the proposed method and clarify several important statistical questions. Also discussed is why and to what extent molecular fluorescence methods are more sensitive than molecular absorption methods.     

Finding of remarkable synergistic effect on the aroxyl-radical-scavenging rates under the coexistence of α-tocopherol and catechins

Measurements of aroxyl radical (ArO^•)-scavenging rate constants () of antioxidants (AOHs) (α-tocopherol (α-TocH) and three catechins (CatHs) (ie, epicatechin (EC), epigallocatechin (EGC), and epigallocatechin gallate (EGCG)) were performed in ethanol solution, using stopped-flow spectrophotometry. values were measured not only for each AOH, but also for the mixtures of two AOHs (α-TocH and CatH). A notable synergistic effect that the value of α-TocH increases 1.29, 1.84, and 1.65 times under the coexistence of constant concentrations of EC, EGC, and EGCG, respectively, was observed for the solutions including α-TocH and CatH. Similarly, values of CatHs (EC, EGC, and EGCG) increased 1.72, 2.25, and 2.34 times under the coexistence of constant concentrations of α-TocH, respectively. UV-Vis absorption of α-tocopheroxyl radical (α-Toc^•) (λ_max = 428 nm), which had been produced by reaction of α-TocH with ArO^•, decreased remarkably under the coexistence of α-TocH and CatHs due to the fast α-TocH-regeneration reaction by CatHs. The result suggests that the prooxidant reaction due to α-Toc^• is suppressed by the coexistence of CatHs. By analyzing the formation and decay curves of α-Toc^•, it has been ascertained that one molecule of EGCG having three OH groups at B-ring may rapidly regenerate three molecules of α-Toc^• to α-TocH.