一种新的求值滴定法

本文提出的这种求值滴定法,只需要二组E-V数据,即可直接算出酸碱、沉淀、络合或氧化还原电位滴定中待测离子的浓度。     

相对滴定法的研究Ⅱ．电位滴定法测定多种弱酸的混合溶液

本实验研究了两种弱酸混合溶液中的相对滴定法。利用该法可分别检测ｐＫａ值相差１的两种弱酸混合溶液中的两种弱酸。     

药用小苏打片中NaHCO3的微型滴定分析

药用小苏打片中ＮａＨＣＯ３的微型滴定分析杨左海（咸宁医学院化学教研室湖北４３７１００关键词小苏打片碳酸氢钠微型滴定法常规滴定法中图分类号Ｏ６５５．２２小苏打片为ＮａＨＣＯ３加淀粉等压制而成，用于碱化尿液及酸血症，也可用于胃酸过多。一般用常规滴定法检测...     

络歙本系中的相对滴定法及其应用于铝的测定

本文提出了络合体系中的相对滴定分析法，它以滴定到一定的状太民时，滴定剂体积与被测物的量之间的线性关系为定量基础，用仪器分析的定量方法进行定量，适应于所有类型的事体系，即使对滴定突跃很小或根本无突跃的体系也同样适用。     

酸碱滴定法与碘滴定法测定维生素C

维生素C是一种重要的营养物质和药物,人体如果缺乏维生素将导致多种疾病的发生,严重时将导致坏血病、心脏及脾脏损伤等疾病.测定维生素的方法很多,主要有碘量法[1]、光度法[2]、电化学法[3]、色谱法[4]等.     

多元线性回归同时单点pH滴定法研究

本文将多元线性回归分析用于单点ＰＨ滴定中，同时测定极弱酸或碱混合物含量。对 十个五元 极弱碱混合样进行了测定，获得满意结果。     

等电位间隔-电位滴定法

对两点电位滴定法作出改进,提出了等电位间隔-电位滴定法。由数学推导证明,当P1的数值(P1为V1与Ve的比值以百分率表示;V1为在第1测量点所耗滴定剂的体积;Ve为滴定终点时所耗滴定剂的体积)达到95%,且在两点间的电位差值(ΔE)大于30mV时,滴定的相对误差(T)的计算值可达到小于0.1%。据此,在滴定过程中,记录两测量点之间的ΔE为30mV时的V及E值,当有两组数据的ΔE达到30mV并算得此时的T值≤0.1%时,即可停止滴定,并根据所给公式计算Ve及滴定结果。将此方法应用于包括中和反应、沉淀反应及氧化还原反应等多种滴定体系的电位滴定,所得结果与常规电位滴定法的测定结果一致。     

电位滴定法测定氰尿酸的含量

氰尿酸（CA），学名2，4，6-三羟基-1，3，5-三嗪。CA在工业上的生产均以尿素为原料，它是一个非常重要的化工产品的中间体，被广泛地应用于合成各种油漆、涂料、除草剂、杀菌剂、漂白剂、金属氰化缓蚀剂以及高分子材料的粘合剂、改性剂、交联剂、抗氧剂等。在有关氰尿酸的生产及科研中，经常要对其含量进行分析，在目前常用的分析方法中，薄层色谱分析方法可靠，但有时受仪器设备等条件的限制；重量分析法（氰尿酰胺沉淀法）和非水酸碱滴定法，操作繁琐且花费时间较长或条件苛刻；以酚酞或甲基红作指示剂进行水相酸碱滴定，结果误差比较大。本文用电位滴定法在水相对氰尿酸的含量进行酸碱滴定分析。     

Process monitored spectrophotometric titration coupled with chemometrics for simultaneous determination of mixtures of weak acids

A new spectrophotometric titration method coupled with chemometrics for the simultaneous determination of mixtures of weak acids has been developed. In this method, the titrant is a mixture of sodium hydroxide and an acid-base indicator, and the indicator is used to monitor the titration process. In a process of titration, both the added volume of titrant and the solution acidity at each titration point can be obtained simultaneously from an absorption spectrum by least square algorithm, and then the concentration of each component in the mixture can be obtained from the titration curves by principal component regression. The method only needs the information of absorbance spectra to obtain the analytical results, and is free of volumetric measurements. The analyses are independent of titration end point and do not need the accurate values of dissociation constants of the indicator and the acids. The method has been applied to the simultaneous determination of the mixtures of benzoic acid and salicylic acid, and the mixtures of phenol, o-chlorophenol and p-chlorophenol with satisfactory results.     

近年物理化学滴定进展

评述了近五年国内外物理化学滴定（用作图确定终点）的新进展，内容包括：（１）光学滴定（含光度、荧光、磷光、化学发光滴定）；（２）电滴定（含电位、电导、电流、库仑滴定）；（３）量热滴定。每类滴定均再按滴定用介质分为水介质和非水介质滴定，按滴定反应分为酸－碱、氧化－还原、络合、沉淀滴定，按滴定方式分为直接滴定、代滴、回滴。引用文献１０６篇。     

聚苯胺修饰电极酸碱示波电位滴定法——Ⅰ.水溶液中的酸碱滴定

示波电位滴定具有终点直观、仪器便宜、操作简便、快速、准确等特点。本文将对氢离子响应敏锐、使用寿命长、制备简单的聚苯胺修饰电极(PAME)^[4,5]应用于酸碱示波电位滴定中,使电位突跃更加明显,化学计量点更易判断(与双铂电极体系比较),可滴定多元弱酸、弱碱、混合酸和混合碱.与pH玻璃电极比较,具有阻抗低,响应灵敏、迅速,终点电位突跃大,不易损坏,不需预处理,制备简单等特点.     

校正矩阵同时2单点沉淀滴定法研究

本文将校正矩阵计算法应用于单点沉淀滴定法中，同时测定了卤素及硫氰酸盐混合物各组分含量讨论了方法原理、指定电位的确定及常数矩阵的建立对２８个二元、三元及四元混合样进行分析，获得满意结果     

沉淀滴定计算分析法同时测定溴酸根与碘酸根

以银电极为指示电极，Ag^ 标准溶液为滴定剂，对BrO3^-,IO3^-的混合离子进行了测定。结果表明：BrO3^-或IO3^-单种离子，测定误差小于1％；BrO3^-与IO3^-混合离子，IO3^-的测定误差约为1％，但BrO3^-的测定误差较大，此外，对BrO3^-,IO3^-与Ag^ 沉淀反应的动力学为进行了研究，并对产生误差的原因进行了讨论。     

Simultaneous determination of halide and thiocyanate ions by potentiometric precipitation titration and multivariate calibration

Halide and thiocyanate ions can be determined by a precipitation titration with silver nitrate as the titrant, and the end-point can be evaluated by a potentiometric method, in which generally a silver indicator electrode is used as the indicator electrode and a double-junction Ag–AgCl electrode as the reference electrode. However, when mixtures of halide and thiocyanate are titrated, it is difficult to determine these components individually for there are overlapping steps in the potentiometric titration curves, especially in the case that there are obvious differences between concentrations of the components. In this paper, the linear equation for the potentiometric precipitation titration of a mixture of halide and thiocyanate ions was developed and it was then used for determining the components in the mixtures simultaneously with the aid of multivariate calibration methods. By application of this model, 27 synthetic mixtures with three- and four-component combinations of chloride, bromide, iodide and thiocyanate with low concentration levels from 1.8×10⁻⁴ to 6.2×10⁻⁴ mol l⁻¹ were analyzed and acceptable results were obtained.     

On The Effect of Ionic Melt Compositions on Their Acid-base Properties

Abstract

Analysis of the ionic solvent effect on acid-base equilibria allowed to divide them in two types distinguishing by the existence of ‘inner’ acid-base equilibrium and, consequently, by type of acid-base intervals. A consideration of some studies of ionic melts on the base of mixtures of AlCl₃ and gallium halides with alkaline halides showed that the effect of melt composition (both cation and anion) on acid-base interval extent is described in the frames of ‘hard’ and ‘soft’ acids and bases (Pearson). Oxobasicity indices of molten mixtures containing alkaline and alkaline earth chlorides at 600 and 700°C are determined, the features of oxoacidity it certain melts are discussed.     

Solubility limits and phase diagrams for fatty acids in anionic (SLES) and zwitterionic (CAPB) micellar surfactant solutions

The limiting solubility of fatty acids in micellar solutions of the anionic surfactant sodium laurylethersulfate (SLES) and the zwitterionic surfactant cocamidopropyl betaine (CAPB) is experimentally determined. Saturated straight-chain fatty acids with n=10, 12, 14, 16, and 18 carbon atoms were investigated at working temperatures of 25, 30, 35, and 40°C. The rise of the fatty acid molar fraction in the micelles is accompanied by an increase in the equilibrium concentration of acid monomers in the aqueous phase. Theoretically, the solubility limit is explained with the precipitation of fatty acid crystallites when the monomer concentration reaches the solubility limit of the acid in pure water. In agreement with theory, the experiment shows that the solubility limit is proportional to the surfactant concentration. For ideal mixtures, the plot of the log of solubility limit vs. the chainlength, n, must be a straight line, which is fulfilled for n=14, 16, and 18. For the fatty acids of shorter chains, n=10 and 12, a deviation from linearity is observed, which is interpreted as non-ideal mixing due to a mismatch between the chainlengths of the surfactant and acid. The data analysis yields the solubilization energy and the interaction parameter for the fatty acid molecules in surfactant micelles. By using the determined parameter values, phase diagrams of the investigated mixed solutions are constructed. The four inter-domain boundary lines intersect in a quadruple point, whose coordinates have been determined. The results can be applied for the interpretation and prediction of the solubility, and phase behavior of medium- and long-chain fatty acids and other amphiphiles that are solubilizable in micellar surfactant solutions, as well as for determining the critical micellization concentration (CMC) of the respective mixed solution.     

Investigation and radiometric determination of saturated and unsaturated aliphatic dicarboxylic acids

Radiometric determination of saturated and unsaturated aliphatic dicarboxylic acids has been developed using a precipitation reaction. The influence of the conditions of precipitation, the composition of the calcium salts of the acids, thepH, and the composition of solvent mixtures were investigated. The solubility of the calcium salts diminished with an increase of the ethanol content in weakly alkaline medium. Linear relations were found between the solubilities of the calcium salts and the dielectric constants of the solvent mixtures. The calcium salts have poor solubilities atpH 9 in 20% aqueous ethanol containing ammonia. The radiometric titrations were carried out in 0.05M solutions, using 0.05M ⁴⁵Ca-labelled CaCl₂ solution in 20% aqueous ethanol. The titrations were done in an apparatus suitable for the detection of soft β-emitting isotopes.