【摘要】 采用HNO3-HClO4湿消化的EDTA减量滴定法测定饲料中的微量铜。即样品用HNO3-HClO4湿消化后,先在pH值5~6时,以二甲酚橙为指示剂,用EDTA标准溶液测定金属离子的总量;然后在另一份试样中,用硫脲掩蔽铜,再用EDTA标准溶液测定铜以外的其他金属离子;两者之差即相当于铜的量。结果表明,该方法没有干扰,准确度高,适用性强,样品消化快捷,测定方法简单,终点易于判断,测定结果的相对标准偏差(RSD)为=0.47%,回收率(R)在98.4%~101.2%。更多还原

【Abstract】 The study on the determining method of copper in the feed with the EDTA was carried out.After the sample was digested with HNO₃-HClO₄,while the pH was 5～6 and the XO was used as the indicator,the total of the metal ions was tested with the standard solution of EDTA,and another sample was added with the thiourea to protect Cu²⁺ and then the ions except Cu²⁺ was titrated by means of EDTA.The amount of the copper was determined through the balance between two values.The result showed it was not disturbed and with the high accuracy,applicability better,sample digest fast,easy-determination and the end point was easily estimated.RSD=0.47%,and R was between 98.4% and 101.2%.更多还原