Separation and Determination of Total Copper and Zinc in Soils
1958
Pratt, P. F. | Bradford, G. R.
Procedures for the anion-exchange separation of Cu and Zn from each other and from other elements, including Fe, are described. An aliquot of soil extract containing Fe in the ferric form and sufficient HCl to make 3M HCl is added to the resin columns, and the columns are washed with 3M HCl to remove ions that do not form or that form weak negative chloride complexes in HCl. The Cu is then eluted with 3M HCl. Ferric-Fe, which moves slowly in the 3M HCl, is eluted with 1M HCl, after which the Zn is eluted with 0.001M HCl. The Cu and Zn are determined colorimetrically by the use of zincon (2-carboxy-2'-hydroxy-5'-sulfoformazylbenzene). The separation and determination of Cu and Zn by these procedures give values in good agreement with dithizone extractions and determinations. The advantages of the new procedures are their simplicity and rapidity. Digestion with HClO₄ does not completely dissolve Zn from soil samples.
显示更多 [+] 显示较少 [-]