Carbonate analysis

[chenjie]

We have an ICS 3000 from Dionex, and we need to develop an analytical method to analyze carbonate in samples. Does anyone have any idea where to start? Does CO2 in air interfere the analysis?

[duantech]

You may go dionex website for more info (column, application notes, etc). And you need to know what anions are in a sample preparation.

Precautional measures (degas, reagent, helium protection) are recommended to eliminate interference from CO2 dissolved in aqeous solution.

best

duantech

[chili]

I analyze carbonate on IC-3000. It is no problem. You can only inject from each vial once, because air interferes. I use degassed MQ-water as mobile fase.

[HW Mueller]

duantech, you want to get rid of CO2 without touching CO3- in the same solution?

[duantech]

Hi, HW Mueller,

What I meant is for diluent and mobile phase preparation, not for sample. There is no way you can remove CO3- by normal degasing procedure. I should've made it clear. Sorry.

best

duantech

[HW Mueller]

Depends on the pH, if "H2CO3" is present you will loose carbonate in a degassing process.

[Markus Laeubli, Metrohm]

We are using suppressed ion exclusion for this analysis in IC. See the respective Application Note.

But to be honest, acid/base titration is the more simple method. And it even gets you more information like carbonate / hydrogen carbonate ration.