To determine the water and magnesium oxide concentration in the decomposition process of magnesium chloride hexahydrate, a new sampling and detecting method was provided. As metal oxide can react with Karl Fisher reagent to form water, this reaction was treated as a side effect. The experiment results showed that this reaction was quantitative. Anhydrous ethanol (the water concentration was less than 0.01％) was used as solvent and liquid seal reagent. It can solve the anhydrous magnesium chloride's moisture absorption problem. High pure nitrogen was used to protect the titration process from atmosphere. By using solid method together with alcohol-solvent method, the water equivalent of magnesium chloride hexahydrate and magnesium oxide individually, the total water equivalent of the mixture, and the concentration of water and magnesium oxide in the mixture were determined. During the titration process of magnesium oxide, some acetic acid can deeply fasten the reaction. This method can detect trace magnesium oxide together with water, and the relative error was less than 2 ％.%针对六水氯化镁热解过程中MgO存在下的H2O的检测问题,对体系的取样过程及分析方法进行了改进.通过乙醇液封的方法,有效避免了无水氯化镁的吸水性问题.在卡尔费休滴定仪进样口引入保护气装置,可以减小空气中水分对滴定过程的干扰.氧化物与卡尔费休试剂的反应常被视为滴定水的干扰反应.实验表明:该反应可用于定量检测MgO.在滴定MgO的过程中,加人适量冰醋酸可显著缩短滴定时间.采用经特殊处理的无水乙醇为溶剂,将醇溶法与固体法相结合,分别测定了六水氯化镁中的含水量和MgO含量,二者混合体系中水及MgO的总含量,以及混合体系中水及MgO的含量.结果表明:卡尔费休容量法可用于同时检测微量MgO及H2O的含量,操作简便,准确度高,相对标准偏差小于2%.
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