EDTA法测定RECl_3(L)稀土总量影响因素分析

Analysis of Influencing Factors on Determination of Total Rare Earth in RECl_3(L) by EDTA Method

采用EDTA滴定法测定混合氯化稀土溶液[RECl_3(L)]稀土总量,研究了玻璃计量器具、分析试剂、样品的均匀性以及非稀土金属离子等对测定结果的影响。研究结果表明:玻璃计量器具对测定结果影响较大,特别是计量器具的误差累积效应,稀土总量修正(最大允许校准误差内)误差达3.66 g/L;铝、铁离子对测定结果的影响可通过加入掩蔽剂消除,锌离子浓度小,对结果的影响可忽略,在日常分析过程中,注意分析试剂的质量和正确使用,保证样品的均一性,减少分析误差,提高分析结果的准确度。

The total amount of rare earth in mixed rare earth chloride solution [RECl_( L) ]is determined by EDTA titration and the effects of glass metering instruments,analytical reagents,sample homogeneity and non-rare earth metal ions on the measurement results are studied. The results show that: Glass metering instruments have the greater impact on the measurement results,especially the error accumulation effect of metering instruments,and errors of total rare earth correction( within the maximum allowable calibration error) can reach 3. 66 g/L; the effect of aluminum and iron ions on the measurement results can be eliminated by adding masking agents; the zinc ion concentration is small and the effect on the results can be negligible. In the daily analysis process,pay attention to analyze the quality and correct use of reagents,ensuring the homogeneity of samples,reducing the analysis error,and improve the accuracy of analysis results.