Simultaneous determination of praseodymium, neodymium, holmium and erbium in rare earth mixtures with ofloxacin

Department of Chemistry, Shandong University, Jinan, 250100, China

Shandong Province City Building School, China

Manuscript received 30 September 1999, revised 3 February 2000, accepted 28 April 2000

A new reagent system has been developed for the simultaneous determination of praseodymium neodimium,holmium and erbium in mixed rare earths. The method is based on the absorption spectra of 4f-electron transitions of Pr, Nd, Ho and Er complexes with ofloxacin. The second derivative spectrum has been used to eliminate the interference and to improve the sensitivity by a further factor of 2-7. Beer's law is obeyed for 7-50 ug ml^-1 of Pr, Nd, Ho and Er. Their relative standard deviation of the absorption signals are found to be 3.8, 2.2, 2.6 and 3.2%, respectively.