Determination of Dimethylallylamine by Titration in Nonaqueous Solvent

The content of dimethylallylamine was determined using glacial acetic acid as solvent, acetic-formic mixture as an anhydrite, perchloric acid-glacial acetic acid as titrant, and 1% crystal violet in acetic acid as indicator in the presence of methylamine and dimethylamine The influences of inert constituents and water on the titration were investigated, and a complete analytical method was determined. The results showed that the determination error of total amines increased with water increasing, while the effect of water on the determination of dimethylallylamine was little when the amount of water was within 5%, the relative error was generally within 1%, and that the end-point was acutely when about 10% chloroform was added. Compared with gas chromatography, this method is simple, convenient and accurate.     

电导滴定联机测定钾盐中钾的含量

提出将电导滴定装置与PC机联机测定钾盐中钾的含量,用专门编写的程序采集滴定数据和动态显示滴定曲线.这种联机方式可以提高分析结果的精密度,平行测定5次,其实验结果的变异系数≤0.1%.     

如何正确理解和使用林邦误差公式

推导了络合滴定终点误差计算的精确公式，并在特定的条件下还原为林邦误差公式。它有助于学生搞清林邦误差公式的本质和使用条件。     

红外光谱法测定苯胺的含量

本文采用红外分光光度法中的标准工作曲线法测定苯胺的含量,与有机微量分析高氯酸非水滴定法作对比,结果表明,其操作简便快捷,试剂用量少,是一种可靠实用的测定方法。     

多元酸含量计算方法改进

对多元酸浓度的计算方法人么改进，采用单纯纯形优化法优化稳定常数，所得结果与实际情况符合良好。通过对一元酸，二元酸，三元酸等体系的计算结果分析表明，单纯形优化法可以获得各种酸浓度相对误差小于１＾的满意结果。     

Carbazole tricationic salt: A novel potential two-photon fluorescent DNA probe for nucleic imaging of cells

A new carbazole tricationic salt, 4,4′-(1E,1′E)-2,2′-(9-(2-(1-(2-hydroxyethyl)pyridinium-4-yl)ethyl)-9H-carbazole-3,6-diyl) bis(ethane- 2,1-diyl) bis(1-(2-hydroxyethyl)pyridinium) iodide (THEPC) was synthesized. Photophysical experiments have shown that THEPC has large two-photon excited fluorescence action cross-sections (33 GM in the presence of DNA), which ranks THEPC as a good biological fluorophore. The results from electronic absorption, circle dichroism and single-/two-photon fluorescence emis-sion spectra suggest that THEPC can strongly bind to DNA, with an intrinsic binding constant of 5.79 × 106 L mol–1. THEPC has better photostability under one- or two-photon excitation conditions. Finally, the staining photos from two-photon fluorescence microscopy (TPM) show that THEPC can exclusively label the nucleus with high contrast and without image distortion. These re-markable properties and optimized imaging ability make THEPC an attractive DNA probe in TPM.     

二氧化锰分析方法的改进

在草酸钠法测定MnO2含量与直接滴定法测定Mn^2 的基础上，提出了一种新的分析电池级二氧化锰的方法。连接采用氧化还原滴定及络合滴定两步滴定，简便快捷，经实验验证，具有很高的准确度和精密度。     

电导滴定法分析4,6-二氨基间苯二酚的纯度

研究了酸碱滴定和AgNO3滴定4,6-二胺基间苯二酚盐酸盐水溶液电导的变化,利用电导滴定曲线变化分析其纯度.通常的滴定方法电导率数值不稳定,转折不明显,提出的碱量法和Ag量法终点明显,其中Ag量法结果准确可靠、重复性好、相对偏差小于0.49%.     

电位滴定法测岩心中水溶性有机酸的含量

采用返滴定方式,电位滴定测定了胜利油田部分岩心中的水溶性有机酸含量,考察颗粒大小、萃取时间、滴定方式等因素对测定结果的影响。实验结果表明,岩心颗粒越小,萃取率越高,萃取时间对有机酸的测定结果有一定影响,加热煮沸60min即可达到萃取平衡。与直接滴定法相比较,电位返滴定法测定具有萃取率高、终点易观察、结果重复性好等优点。     

铝离子碱滴定曲线的理论计算与水解途径分析

根据铝离子主要的水解聚合平衡反应及其相应的热力学平衡常数,首次尝试对Al3 的碱滴定曲线和相应的羟基聚合铝各形体的分布分数曲线进行完整的理论计算.计算得到的曲线其形状和变化趋势由实验测试结果加以印证.曲线有两个滴定突跃,随着浓度的降低,突跃范围减小.分布分数曲线显示,Keggin-ε-Al13和Al6(OH)153 是羟基聚合铝的主要形体,当COH/CAl=2.12~2.19时,Keggin-ε-Al13的浓度达到极大值.理论计算的偏差暗示着铝离子还存在着其它的水解途径.