蛇纹石中MgO的测定方法  

Determination of MgO in Serpentine

作　　者：张伟[1] 龚云麒[1] 张国丽[1] 

机构地区：[1]昆明制药集团股份有限公司药物研究院,云南昆明650100

出　　处：《云南中医学院学报》2011年第3期30-32,共3页Journal of Yunnan University of Traditional Chinese Medicine

摘　　要：目的:建立蛇纹石中氧化镁(MgO)的含量测定方法。方法:采用盐酸溶液溶解蛇纹石样品,用氨-氯化铵缓冲溶液调pH=10.0,5%酒石酸钾钠、三乙醇胺水溶液和铜试剂掩蔽干扰离子,用乙二胺四醋酸二钠滴定液(0.05mol/L)配位滴定,用K-B指示剂确定终点,测定蛇纹石中的Mg2+离子的量,计算为MgO的含量。结果:酸浸取法操作简便,采用金属离子掩蔽剂,方法专属。Mg2+离子在3.357mg^10.071mg范围内呈良好线性关系。回归方程为:V=0.824 5×m-0.108 3,r=0.999 9(n=5),平均回收率为100.0%,RSD为2.3%.结论:该方法简便、准确性好,适用于蛇纹石中MgO的含量测定。Objective：To establish a method for the determination of magnesium oxide（MgO） in serpentine.Method：HCl is used to dissolution the sample directly.In the ammoniacal buffer solution that pH is 10.0,triethanolamine、potassium sodium tartrate and sodium diethyldithiocarbamate are used to cover interference ions.MgO is determined by EDTA titrametic method with the K-B indicator.Results：The calibration curve is linear in the range of 3.357mg～10.071mg for magnesium ion,the regression equation being V=0.824 5×m-0.108 3,r=0.999 9（n=5）,and the average recovery was 100.0% with RSD 2.3%.Conclusion：The end point is changing obviously and the method is simple,accurate and reproducible for quality control of serpentine.

关 键 词：氧化镁 EDTA 配位滴定 

分 类 号：R284[医药卫生—中药学]