Study of the absorption spectra of 4f electron transitions of the neodymium and erbium complexes with diphacinone and Triton X-100 and its analytical application

Abstract

Abstract The absorption spectra of 4 f electron transitions of the neodymium and erbium complexes with 2-(diphenylacetyl)indan-1,3-dione and octylphenol poly(ethyleneglycol)ether have been studied by normal and derivative spectrophotometry. Use of third-derivative spectra can eliminate the interference from other rare earth elements and enhance the sensitivity for neodymium and erbium. Beer's law is obeyed for 0–35 μg cm −3 of neodymium and 0–50 μg cm −3 of erbium. Their molar absorptivity at the maximum absorption bands are about 7.4 times for neodymium and 11.4 times for erbium greater than that for the equivalent amount of neodymium and erbium in the chlorides. The relative standard deviations evaluated from seven independent determinations of 8.3 μg cm −3 of neodymium and 8.5 μg cm −3 of erbium are 1.4 and 1.5%, respectively. The detection limits (signal to noise ratio = 2) are 0.06 μg cm −3 for neodymium and 0.1 μg cm −3 for erbium. A method for the direct determination of neodymium and erbium in mixtures of rare earth elements with good accuracy and selectivity, is described.