I am seeing a drop in Area Counts across Standards, even with fresh, new stock. I am trying to identify any other possibility besides having contaminated the column as it was just installed 4-5 months ago, but haven't had much luck. In my other lab, we had different columns and trimming was a way of life there. However, I remember reading somewhere that it was not advisable to trim these types of columns. Is this correct? I haven't trimmed this particular column yet but was beginning to think about it, and thought I should "ask the experts."