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

A new reagent system has been developed for the simultaneous determination of praseodymium. neodymium, holmium and erbium in mixed rare earths. The me thod is based on the absorption spectra of 4f-electron transitions of Pr, N d, Ho and Er complexes with ofloxacin. The second derivative spectrum has b een used to eliminate the interference and to improve the sensitivity by a further factor of 2 similar to7. Beer's law is obeyed for 7 similar to 50 m ug ml(-1) of Pr, Nd, Ho and Er. Their relative standard deviation of the al ,sorption signals are found to he 3.8, 2.2, 2.6 and 3.2%, respectively.