寒水石始载于《神农本草经》,原名“凝水右”,具有清热降火,除烦止渴的功用。现今市售品有两种,即红石膏和方解石。北方地区多用红石膏,生制品主含二水合硫酸钙,煅制品主含无水硫酸钙;南方地区多用方解石,方解石的生制品和煅制品的主要成分均为碳酸钙。本文对炮制前后寒水石中主要成分的含量测定方法进行了探讨。测定常量钙,常用EDTA容量法。在pH ≈13的样品溶液中,以钙指示剂和钙黄绿素做指示剂,用EDTA直接进行滴定。采用钙指示剂测定方解石中的钙时,需加三乙醇胺和L— The cold water stone was originally contained in the “Shen Nong Ben Cao Jing”, formerly known as “condensing water right”. It has the function of clearing away heat and reducing heat, eliminating trouble and thirst. There are two types of commercial products available today, namely red plaster and calcite. In the northern areas, red gypsum is mostly used. The raw products contain calcium sulfate dihydrate. The calcined products mainly contain anhydrous calcium sulfate; in the south, calcite is used in many ways; the main components of the calcite production and calcined products are calcium carbonate. In this paper, the determination methods of the main components in the cold water before and after processing are discussed. Determination of calcium, commonly used EDTA volumetric method. In a sample solution of pH ≈13, titration was performed directly with EDTA using a calcium indicator and calcein as an indicator. When using calcium indicator to measure calcium in calcite, triethanolamine and L need to be added—