Graphite Furnace Atomic Absorption Spectrometric Determination of Iron,Cobalt,Nickel,and Copper at Parts-Per-Billion Level in High-Purity Lanthanum Fluoride

This paper describes an analytical method for the quantitation of iron, cobalt, nickel, and copper in lanthanum fluoride at trace levels with graphite furnace atomic absorption spectrometry (GFAAS) without using any matrix modifier. These metals were preconcentrated in HNO₃ and analyzed directly. The detection limits for iron, cobalt, nickel, and copper were found to be 3, 1, 2, and 2 ppb, respectively. The average precision of measurements (°/o RSD) for all the elements was <10%.