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Ammonium Bicarbonate Buffer
Posted: Fri Nov 04, 2005 12:51 am
by AMR
I am using Ammonium Bicarbonate pH 8.0 mobile phase for an assay and I am having a few problems with the stability of the pH. Does anyone know of any tricks to keep the the pH stable? Are there any preocedures during preparation that may help?
Posted: Fri Nov 04, 2005 1:19 am
by tom jupille
Degas the water before you make the buffer, and then make sure you use a CO2 trap on the reservoir.
Posted: Fri Nov 04, 2005 1:33 am
by Mark Tracy
Tom's remark about degassing prior to mixing is important. Degassing ammonium bicarbonate buffer will change its pH.
Posted: Fri Nov 04, 2005 3:24 am
by Uwe Neue
Unfortunately, the pH of an ammonium bicarbonate "buffer" in this pH range or at lower pH will change anyway. The formation of CO2 appears to be slow. The pH of the buffer is unstable with time, even if it is degassed properly to start with.
Posted: Fri Nov 04, 2005 7:19 am
by HW Mueller
On top of this, the buffer is not so hot at pH = 8.