1.1 ,This practice provides instructions for the rapid separation of lanthanide elements using high pressure ion chromatography (HPIC) from dissolved uranium materials such as: nuclear fuels, uranium ores, hydrolyzed UF₆, and depleted, natural, or enriched oxides/powders, or metals. When optimized, this technique will produce purified elemental fractions of the lanthanide elements isolated from the bulk uranium matrix allowing for isotopic assay using inductively coupled plasma mass spectrometry (ICP-MS).