AG MP-1阴离子交换树脂元素分离方法研究

Separation of Some Elements Using AG MP-1 Anion Exchange Resin

在用多接收器等离子体质谱仪(MC-ICP-MS)测定过渡族元素同位素时,需要对待测样品进行分离纯化。目前,人们常用AGMP-1阴离子交换树脂在不同浓度的HCl和HNO3介质中依次分离出Cu,Fe和Zn。为详细了解样品中基体元素与AGMP-1阴离子交换树脂的作用以及它们在该树脂中的淋洗过程,根据金属阳离子与Cl-形成络合物的稳定性及它们与阴离子交换树脂的亲和力,对利用AGMP-1进行Cu和Fe分离过程中基质元素的行为进行了实验研究。结果表明,除Co外,在7mol/LHCl条件下,地质样品中基体元素(包括Cr和Ni)能与Cu,Fe进行很好的分离。不同酸度下的实验研究表明,在6mol/LHCl条件下,可以将Cu和Co进行很好的分离。为此提出,对于基质元素含量较少的样品(如硫化物、氧化物、氢氧化物等),可直接用6mol/LHCl进行样品分离。由于这类样品中K,Na,Ca,Mg,Al等元素含量较低,在Cu被洗脱前已被彻底淋洗,该方法可将Cu和包括Co在内的基质元素进行理想的分离。对于含Co较高的部分硅酸盐等样品,则应先用7mol/LHCl分离出Cu接收液,之后过二遍柱,以6mol/LHCl作淋洗液,去掉Co。建立的分离方法还可应用于Ca,Mg同位素的前期分离纯化。

The anion exchange resin AG MP-1 is commonly used for the separation of Cu, Fe and Zn from other elements. Detailed experiments have been carried out to investigate the behaviour of matrix elements during the separation. The results demonstrate that Cu and Fe can be well separated from matrix elements （ including Cr and Ni） using 7 mol/L HCl, with exception of Co. The results of experiments using different acidities of HCl show that separation of Cu from Co can be achieved using 6 mol/L HCl, where Co is eluted prior to the elution of Cu. We therefore suggest using 6 mol/L HCl for Cu separation for samples with relative simple chemical compositions, such as sulphides, oxides and hydroxides. In this case, Cu can be well separated from Co and other elements, as these kinds of samples have low contents of Na, Ca, Mg and Al. For silicate samples with high Co contents, a twocolumn-precedure may be used to achieve total separation of Cu from matrix elements, i. e. , separation of Cu from the majority of matrix elements using 7 mol/L HCl, then separation of Cu from Co using 6 mol/L HCl, with the same column. Besides, the methods developed here may be used for separation of Ca and Mg from Fe, Cu, Zn and Co.