原子吸收光谱法测定钴粉中镍

Determination of nickel in cobalt powder by atomic absorption spectrometry

研究了萃取分离原子吸收光谱法测定钴粉中镍的方法。在pH8～9氨性介质中,以柠檬酸作为稳定剂,用三氯甲烷萃取丁二酮肟-镍的络合物,盐酸反萃取后用原子吸收光度法测定反萃取液中镍含量。试液经萃取分离后基体和共存元素对镍的测定没有干扰,方法的检出限为0.002%(质量分数),镍的质量浓度在0.4～150μg/mL范围内与其吸光度呈线性关系,相关系数大于0.999 6。方法已用于钴粉中微量镍的测定,测定结果与电感耦合等离子体原子发射光谱法(ICP-AES)的结果相符,相对标准偏差(RSD,n=11)小于2.7%。

A method for the determination of nickel in cobalt powder by atomic absorption spectrometry after extraction separation was studied. In ammonia medium at pH 8-9, the dimethylglyoximenickel complex was extracted by chloroform using citric acid as stabilizer. After reextraction with hydrochloric acid, the content of nickel in reextraction solution was determined by atomic absorption spectrometry. The matrix and coexisting elements after extraction separation had no interference in the determination of nickel. The detection limit of method was 0. 002 % （mass fraction）. The absorbance was linear to the mass concentration of nickel in range of 0.4-150μg/mL with correlation coefficient higher than 0. 9996. The method was applied to the determination of micro nickel in cobalt powder. The results were consistent with those obtained by inductively coupled plasma atomic emis- sion spectrometry （ICP-AES）. The relative standard deviation （RSD, n=11） was less than 2.7%.