Abstract: Method and apparatuses are disclosed for removing fine-grained particles from a gaseous sample stream from fluidized catalytic cracking regeneration unit. In one method, the fine-grained particles are wetted with condensate in a sampling system, then the wetted fine-grained particles are separated from the gaseous stream in a wetted packed column in the sampling system. The separated gaseous sample stream is cooled to remove condensible gases then is reheated. The separated fine-grained particles are kept wetted in the sampling system to prevent fouling of the sampling system, then stream is used as a motive force to return the wetted fine-grained particles to the fluidized catalytic cracking regeneration unit. The stream also is used as a drying agent to at least partially dry the wetted fine-grained particles outside of the sampling system and as a dilution agent to help prevent corrosion.