We replaced and conditioned the column in our GC. When we try running a new calibration curve we are seeing lower abundances than normal. We re-ran old dilution sets and also got low abundances, however, when we were running the old column those same samples had much higher abundances. We tried cutting the column and loosening the ferrules, ran and air and water check and have recently cleaned our EI source. Has anyone run into this issue or know of what we should try next to resolve this?