氯离子选择性电极-标准加入法测定碳酸稀土中氯

发布时间：2018-06-23 02:59

本文选题：标准加入法 + 氯离子选择性电极　；参考：《冶金分析》2017年04期

【摘要】：采用HNO_3(1+2)溶解样品,氯则全部以Cl~-形式溶解于溶液中,通过测定溶液中Cl~-质量浓度,即可计算出碳酸稀土中氯含量。试验探讨了在以硝酸钾和柠檬酸三钠为总离子强度调节缓冲溶液(TISAB)体系中,主要以EDTA溶液络合稀土离子,采用氯离子选择性电极-标准加入法测定碳酸稀土中氯含量的方法。结果表明:溶液中Cl~-质量浓度在2.0~40.0mg/L范围内,EDTA溶液和TISAB溶液用量均为10mL,Cl~-质量浓度的负对数与相应电极电位(E)呈良好线性关系,线性相关系数为0.999 9;为保证测试结果的准确性,样品和电极响应斜率S值的测定须在同一恒温体系下进行;方法检出限为0.947mg/L;对于5mg/L的Cl~-,大量K~+、Na~+、NO_3~—不干扰Cl~-的测定,RE~(3+)、Ca~(2+)、Fe~(2+)、Na~+最大允许量分别为10.0、4.0、5.5、23g/L。按照实验方法测定碳酸镧和混合碳酸稀土中氯,结果的相对标准偏差(RSD,n=5)均小于5%;测定值与氯化银比浊法的测定值基本一致。
[Abstract]:HNO3 (12) was used to dissolve the sample, and chlorine was dissolved in the solution in the form of Cln-. The chlorine content in rare earth carbonate can be calculated by determining the concentration of Cln- in the solution. In the system of potassium nitrate and trisodium citrate as total ion intensity adjusting buffer solution (TISAB), the method of chloride-selective electrode and standard addition method was used to determine the chlorine content in rare earth carbonate by complexing rare earth ions with EDTA solution. The results show that the negative logarithm of the concentration of EDTA and TISAB in the range of 2.0 渭 g / L and 10 mL / L of TISAB has a good linear relationship with the corresponding electrode potential (E), and the linear correlation coefficient is 0.999, in order to ensure the accuracy of the test results, The detection limit of the method is 0.947 mg / L, and for the 5mg / L Cli, a large amount of K ~ + Na ~ no _ 3O _ 3N ~ (3) -no _ (2) Ca ~ (2) Fe ~ (2) Na ~ (2) Na ~ (2) Na ~ (2) Na ~ (2) Na ~ (2) N ~ (2) is 10.0 ~ (4. 0) ~ 5. 5 ~ (23) g 路L ~ (-1) 路L ~ (-1) for 5 mg 路L ~ (-1) Cl ~ (-1). The determination of chlorine in lanthanum carbonate and mixed rare earth carbonate by the experimental method shows that the relative standard deviation (RSD) of the results is less than 5, and the determination value is basically the same as that determined by the silver chloride turbidimetric method.
【作者单位】：赣州有色冶金研究所;江西离子型稀土工程技术研究有限公司;
【分类号】：TQ133.3;O657.15

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