电解重量法和电感耦合等离子体原子发射光谱法在测定氧化镍中镍钴铜锌铁锰中的应用

使用硝酸和高氯酸溶解氧化镍样品,溶液过滤后,采用恒电流电解重量法测定滤液中镍。加入10 mL 500 g/L柠檬酸铵,电解液酸度为pH 10,电解过程中所需的电解电流和电解时间为2 A/2 h。选择Ni 341.486 nm、Co 238.892 nm、Cu 324.752 nm、Zn 206.191 nm、Fe 259.940 nm、Mn 257.610 nm作为分析谱线,采用基体匹配法绘制校准曲线消除基体效应,使用电感耦合等离子体原子发射光谱法(ICP-AES)测定沉积在铂阴极上的钴、铜、锌、铁、锰,并测定电解残余液和酸不溶残渣中的镍、锰、铁。镍、铁、锰含量分别为电解在铂阴极的镍、铁、锰,电解液中残余镍、铁、锰,残渣回收浸出液中镍、铁、锰共3个部分测定值的总和。实验方法各元素的检出限为0.002 4～0.020 μg/mL,校准曲线的线性相关系数均大于0.999。按照实验方法测定氧化镍样品中镍、钴、铜、锌、铁和锰含量,测定结果的相对标准偏差(RSD,n=10)在0.11%～7.5%之间。实验方法用于氧化镍样品的测定,结果与国标方法以及原子吸收光谱法的测定结果相吻合。

Application of electrolytic gravimetry and inductively coupled plasma atomic emission spectrometry in the determination of nickel,cobalt, copper,zinc, iron and manganese in nickel oxide

The nickel oxide sample was dissolved with nitric acid and perchloric acid. After filtration, the nickel in filtrate was determined by constant current electrolytic gravimetry. 10 mL of 500 g/L ammonium citrate solution was added. The pH of electrolyte was 10. The electrolysis current and time was 2 A and 2 h, respectively. Ni 341.486 nm, Co 238.892 nm, Cu 324.752 nm, Zn 206.191 nm, Fe 259.940 nm and Mn 257.610 nm were selected as the analytical lines. The calibration solution was prepared by matrix matching method to eliminate the matrix effect. The cobalt, copper, zinc, iron and manganese deposited on platinum cathode were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Then, the nickel, manganese and iron in electrolytic residual solution and acid-insoluble residue were determined. The content of nickel, manganese and iron was the sum of results obtained from platinum cathode, electrolytic residual solution and acid-insoluble residue. The detection limits of elements in this method were in range of 0.002 4 and 0.020 μg/mL. The linear correlation coefficients of calibration curves were higher than 0.999. The content of nickel, cobalt, copper, zinc, iron and manganese in nickel oxide sample was determined according to the experimental method, and the relative standard deviations (RSD, n=10) of determination results were between 0.11% and 7.5%. The proposed method was applied to the determination of nickel oxide samples, and the found results were consistent with those obtained by the national standard method and atomic absorption spectrometry