Hi. I have been having a strange problem with my FPLC (pharmacia, M-7 valve) when I inject samples and tracers. I started noticing that i was getting split peaks. I thought this was my column so i tried a new one and it still produced split peaks. Then I decided to inject a tracer through the system without the column. I still got split peaks. Could it be a problem with my valve? has anyone ever encountered this before?