氢氧化钠标准液(下称标准碱液)为药品分析最常用的标准溶液之一。其配制方法有浓碱法、石灰法、酒精法和金属法。其中浓碱法即利用碳酸盐在饱和氢氧化钠液中不溶而沉淀分离除去的方法,为中国药典1977版所采用。由于碳酸盐沉淀分离方法(过滤法、离心法、静置法和温热法)不同,碱液中所含碳酸盐的含量,文献报道不一。中国药典1977年版采用静置法 Sodium hydroxide standard solution (hereinafter referred to as standard lye) is one of the most commonly used standard solution for drug analysis. The preparation methods are concentrated alkali method, lime method, alcohol method and metal method. Among them, the concentrated alkali method, that is, the method of precipitating and removing carbonates by dissolving them in a saturated sodium hydroxide solution, is adopted by the Chinese Pharmacopoeia 1977 edition. Due to the carbonate precipitation separation method (filtration, centrifugation, standing and warm method) is different, the content of carbonate contained in lye, reported in the literature. Chinese Pharmacopoeia 1977 version of the static method