The invention relates to a process for reducing the concentration of a fluorinated alkyne impurity, such as 3,3,3-trifluoropropyne (TFPY), in 2,3,3,3-tetrafluoropropene (HFO-1234yf) which comprises contacting such a mixture with a caustic material, such as sodium hydroxide (NaOH), under conditions effective to reduce the concentration of the fluorinated alkyne impurity, including in some practices reducing the concentration by at least about 50%.