Determination of Selected Lanthanoid Elements by Atomic-Absorption Spectroscopy Using Electrothermal Atomization

摘要

Optimum ashing and atomization temperatures were established for the following lanthanoids in synthetic solutions containing 1% hydrochloric or nitric acid: praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. Samarium, europium, and terbium were subsequently investigated in more detail. Atomization from a tantalum surface greatly improved the efficiency of atomization of terbium but hardly affected that of samarium and europium. Tantalum-metal strips, boats, and platforms were found to be superior to tantalum carbide coatings for this purpose. Interference effects from the other lanthanoids and yttrium on the response of the analyte were established across the widest possible analytical range at ratios of interferent to analyte of 10, 50, and 100:1 and were found to be most severe for terbium and least severe for europium. Several reference materials were analyzed for ten of the lanthanoids, and it was found that samarium, europium, thulium, and ytterbium can be determined direct by atomic-absorption spectroscopy using electrothermal atomization; holmium, erbium, and dysprosium require the use of the method of analyte additions; and terbium, lutetium, and gadolinium cannot be measured by this method with any degree of accuracy. The laboratory method for the determination of samarium, europium, thulium, and ytterbium is detailed in an appendix. (ERA citation 11:027811)