容量分析Titration

滴定反应必须定量、快速、有合适的终点指示方法。按反应类型分为酸碱滴定、氧化还原滴定、配位（络合）滴定和沉淀滴定。终点通过指示剂颜色变化或仪器信号（电位、电导、光度）判断，指示剂变色点（滴定终点）与化学计量点之间的差异造成终点误差。滴定方式有直接滴定、返滴定、置换滴定和间接滴定。

A titration reaction must be quantitative and fast and have a suitable end-point indicator. By reaction type there are acid–base, redox, complexometric and precipitation titrations. The end point is detected by an indicator colour change or an instrumental signal (potential, conductance, absorbance), and the gap between the indicator's end point and the equivalence point causes end-point error. Titrations may be direct, back, displacement or indirect.

1729 年法国化学家若弗鲁瓦用滴定测定醋的浓度。1791 年德克鲁瓦西尔改进了装置。19 世纪盖-吕萨克建立了氧化还原滴定和沉淀滴定方法并命名了滴定管和移液管，1855 年莫尔出版了容量分析教科书并设计了莫尔盐和莫尔法。1945 年施瓦岑巴赫用 EDTA 建立了配位滴定。

In 1729 the French chemist Geoffroy titrated vinegar to find its strength, and Descroizilles improved the apparatus in 1791. In the nineteenth century Gay-Lussac developed redox and precipitation titrations and named the burette and pipette, and in 1855 Mohr published a textbook of volumetric analysis and devised Mohr's salt and Mohr's method. In 1945 Schwarzenbach established complexometric titration with EDTA.

容量分析操作简便、准确度高（相对误差约 0.1%–0.2%）、成本低，广泛用于工业原料和产品质量检验、水的硬度和化学需氧量测定、食品酸度和维生素 C 测定、药物含量测定（药典方法）以及卡尔·费休滴定测定微量水分。自动电位滴定仪提高了效率和客观性。

Titration is simple, accurate (relative errors of about 0.1–0.2%) and cheap, and is widely used for quality control of industrial materials and products, water hardness and COD, food acidity and vitamin C, drug assays in pharmacopoeias and Karl Fischer titration of trace water. Automatic potentiometric titrators improve speed and objectivity.