旋转圆盘电极原子发射光谱法测定镍电解液中微量铜

镍电解液的复杂高盐基体对其中微量铜的监测产生干扰。将旋转圆盘电极原子发射光谱(RDE-AES)与标准加入法结合,无需样品前后处理,无基体效应,采用改进后的校准曲线测定镍电解液工艺流程中不同中间液中的微量铜。根据元素蒸发曲线,确定预燃时间6 s、采集时间7~30 s,预燃激发改善了盘电极的润湿性,从而保证进样量的稳定性;合理的曝光时间可以在保证分析元素强度灵敏度的前提下提高分析速度,单次检测时间小于35 s。选用Ni 324.845 7 nm为内标,校正激发行为和进样量误差。方法检出限为0.15 mg/L。按照实验方法测定镍电解液工艺流程中不同中间液中微量铜,结果的相对标准偏差(RSD,n=6)小于12%,加标回收率为98%～110%。

Determination of micro copper in nickel electrolyte by rotating disk electrode atomic emission spectrometry

The complex high-salt matrix of nickel electrolyte has interference with the monitoring of micro copper. In this experiment, the rotating disk electrode atomic emission spectrometry was combined with standard addition method. The sample pretreatment was not required and there was no matrix effect. The improved calibration curve was used to determine the micro copper in different intermediate solution of nickel electrolyte. According to the evaporation curve of element, the pre-combustion time of 6 s and acquisition time of 7-30 s were determined. The precombustion excitation improved the wettability of the disk electrode, thus ensuring the stability of the injection quantity. Reasonable exposure time could improve the analysis speed on the premise of ensuring the intensity sensitivity of analytical elements, and the single detection time was less than 35 s. Ni 324.845 7 nm was selected as the internal standard to correct the excitation behavior and injection volume error. The limit of detection was 0.15 mg/L. The content of micro copper in different intermediate solution of nickel electrolyte was determined according to the experimental method. The relative standard deviations (RSD, n=6) were less than 12%, and the recoveries were between 98% and 110%.