Inductively coupled plasma mass spectrometry (ICP-MS) has been widely used in various research fields because of its high-sensitivity, and has played an important role in the certification of fine ceramics reference materials developed in NMIJ, AIST. However ICP-MS often suffers from problems due to spectral interferences; especially the removal of isobaric interference is almost impossible even with high-resolution ICP mass spectrometer. In the precise quantitative analysis of V in fine ceramics using ICP-MS, the isobaric interference causes severe problems because the mass spectra for one of the two V isotopes overlaps with that for ⁵⁰Ti and ⁵⁰Cr. The author has developed a new method for determination of V in the presence of Ti and Cr using ICP-MS with a CH₃F + NH₃ mixed reaction gas to realize selective separation of V as the form of [VF₂(NH₃)₄]⁺. This improved method enabled precise determination of V at the concentration level of mg kg^-1 in fine ceramics. The elimination technique of isobaric interference will expand application of high-sensitive ICP-MS.