Because of its versatility, inductively coupled plasma-mass spectrometry (ICP-MS) is finding applications for trace multielement analysis in many fields. The technique has high sensitivity for the measurement of the long-lived technetium isotope Tc-99. When using the ICP-MS technique, a key aspect of the development of a radiochemical separation procedure for technetium is that it should be optimized to achieve a maximum decontamination factor for the isobaric interfering ruthenium. Different methods, e.g., precipitation, anion/cation exchange, and solvent extraction, have been used. Comparison of the decontamination factors of Ru and the percent recoveries for various processes are reported. Complete decontamination, as required for environmental samples, was achieved.