Traditional methods of quantitation of radioactive isotopes includeradioactivity counting and thermal ion mass spectrometry (TIMS). These techniquesrequire extensive matrix separation and sample purification methods beforeunequivocal identification of specific isotopes and their relative abundanceis possible. Counting techniques become very time consuming when the half-lifeof the target analyte is very long or the concentration of the analyte low.Atom counting using ICP-MS meets the nuclear industry requirements for manyactinides and their daughter products. Recent improvements in quadrupole ICP-MSsignal-to-background have resulted in attogram mass detection capability andimproved analysis of shorter half-life isotopes.