双水相体系萃取光度法测定镧的研究

Extraction-Spectrophotometric Determination of La(Ⅲ) by Using Non-Organic Solventsi

研究了铝试剂作为萃取剂和显色剂，在聚乙二醇（PEG）-铝试剂-硫酸铵（NH4）2SO4体系中的非有机溶剂萃取光度法测定镧。对铝试剂-La（Ⅲ）配合物从pH5．6（HAc—NaAc缓冲溶液）的溶液中萃取至PEG相，其最大吸收波长位于480nm，摩尔吸光系数为1.40×10^4L·mol^-1·cm^-1，La（Ⅲ）的线性范围为0～30μg·ml^-1，La（Ⅲ）与铝试剂的配合比为1：3。将此方法用于铝合金中镧的测定，获得满意结果。

In PEG-alumino-（NH4）2SO4 system, the spectrophotometric determination of La （Ⅲ ）by using alumino as extractant and devolopment agent of non-organic solvents was studied. Complex was extracted by PEG phase from the water solution of pHS. 6 （Hac-NaAc）,The maximum absorption of the compex is at 480nm and the molar absorptivity 1.40× 10^4L·mol^-1· cm^-1. Beer＇s raw was obeyed in the range of La（ Ⅲ ） 0-30μg· ml^-1 The malar ratio of La（ Ⅲ） and alumino in a stable complex is 1：3. The method has been applied to the determination of nickel in aluminium alloy with satisfactory results.