铬兰黑R及镁(Ⅱ)——铬兰黑R配合物极谱行为和分析应用研究

STUDIES ON POLAROGRAPHIC BEHAVIOUR OF ERIOCHROME BLUE BLACK R(EBBR), Mg(Ⅱ)——EBBR COMPLEX AND ITS ANALYTICAL APPLICATION

微量镁的存在可以大大改善高温合金的许多性能。但现有高温合金中微量镁测定方法的灵敏度及准确度还不能满足要求。本文提出以镁(Ⅱ)—铬兰黑R配合物极谱波测定镁(Ⅱ)的方法。线性范围1.7 × 10^(-7)～2.5 × 10^(-5) mol·dm^(-3),检测下限5.5 × 10^(-8) mol·dm^(-3)借助于乙酰丙酮一氯仿,铜试剂—氯仿,萃取剂(Ⅱ)一氯仿联合萃取,稀盐酸反萃的分离方法测定了镍盐及GH33高温合金中微量镁结果满意,并探讨了配合物电极反应机理。

The existence of trace magnesium greatly improves some properties of superalloys. But up to now the sensitivity and accuracy of the analytical methods used for determining trace magnesium can not meet the requirement of practical analysis. So, the method for determining trace Mg by using Mg (II)-EBBR complex adsorptive wave has been established. The linear range of the relationsihp between peak height and Mg(II) concentra-ti on is 1.7×10-7-2.5×10-5mol. dm-3. The sensitivity is 5.5×10-3 mol. dm-3 Mg(II). The amount of trace Mg in nickel chloride salt and GH33 super-alloy was determined by the aid of preseparation-the successively extraction with acetyla cetone (AA)-chloroform, sodium diethyl dithiocarbamate (NAD-DTC)-chloroform, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP)-me-thyl isobutyl keton (MIBK) and, at last, re-extraction with dilute hydro-chloride acid. The results were satisfactory. The electrode reaction mechanism of EBBR and Mg(II)-EBBR complex was investigated as well.