Dear GC-IRMS users Changing ferrules on my GC-C-IRMS Delta plus XP, exactly on the metal Valco piece, that one receiving the flux from GC and distributing it to 3 out ports (a split to a Cuadrupole DSQ, a second split to the oxidation column, and of course the exit to the Backflush, so it is a "Cross" and not a "T" as usual) I have realized that there is a deep blockage on it, probably with the rest of a ferrule. I am not able to get ride of it. Could anyone out there give me a clue to clean this piece. What about using a glass/quartz "X" instead? Thanks Rafa Dr. Rafael Núñez Gómez Colaborador I+D+I Servicio de Isótopos Estables Estación Experimental del Zaidín CSIC Profesor Albareda 1, 18008 Granada, Spain Tf +34958181600 Ext 228 fax +34958129600