Chromatography Forum

Hi,

I have a problem , but since I'm a noob in ion chromatography, I have to understand a couple a things before doing annything else.

The system: Dionex DX-120: AG23 , AS23 (4 mm), ASRS, DS4 Detector
The samples: Sea water samples: > 30 000 mg/l Chlorides

1) How much chlorides can I actually inject through my column? I use to dilute my samples 100 times, but I would like to not dilute them at all, Can it destroy my column (is this what is called overloading?)

2) What is the alternative, if I can't inject so much of an analyte? I heard about a column switching method that removes chlorides, how?? Ag+ Cartdridge is not an option for me.

3) What is actually the point to have a guard column? Is this just a small separation column?

4) Do you have some good links that explains ion chromatography, like i said, i am a noob, but i am willing to learn.

Thanks!

Dear Mox

Overloading does not destroy the column, but leads to overlapping with the peaks of interest.

Columns switching might be a solution but depends on the ions of interest and the instrumentation (I assume that it would be difficult with a DX-120).

The guard column protects the analytical column. In case of interfering components or particles there is a good chance that they only interfere with the guard material. Then you exchange the guard and not the analytical column.

For short intorduction to IC you may contact your local Metrohm Rep and ask for the free Monograph "Practical Ion Chromatogaphy".

For your application request you best check back with your DX-Rep.