Has anyone here tried using the 3x150mm AS14A Analytical column on the ICS-90 for anion analysis? I am having a bitch of a time getting the low-end calibration to work, although higher standards seem to work great. I was running the 4x250mm column with plenty of success.

Hey , I `ve been using almost the same column, but it was AS14. I gather the AS14A is the more advanced version. When I ran it, I used it for the Sulfate quantification and my lowest point was 5uM of sodium sulfate and the injection volume was 10uL, and the eluent was standard (carbonate-bicarbonate), so I got good linearity .
Right now I am actually using another column, the AG9-HC, for higher ionic strenght solutions, and trying to determine acetate in the sediment extract. I ran into the same problem as you did: the low end has higher conductivity responce than the upper end, and my explanation is probably because I am getting the contamination in my samples... I am not sure about it.