selection of detector for quantification of non chormophoric

[ursmahin]

Hi,

I would like to develop a chromatographic quantificaiton method for calcium gluconate.

Its non UV chromophoric compound. I am looking for your suggestions and inputs.

1) Ion chromatography: By estimating the calcium content

2) Derivative technique: By derivitization with EDTA

3) Estimating the gluconic acid and then calculate the calcium gluconate.

4) Can i select RI detector for this method?

I dont have ELSD, Fluorescence detector. If they can be used for this quantification instead of RI.

Please suggest other possibilities.

Thanks

[Markus Laeubli, Metrohm]

Dear Ursmahin

Calcium gluconate can be analyzed in different ways:

USP requires calcium titration.
Calcium by IC has the advantage thatyou also get information about other cations in the sample (Li Na ammonium K Mg). Gluconate can be done by IC as well, once with anion exchange (conductivity or pulsed amperometric detetcion) and second by ion exclusion. Anion exchange gives you traces of inroganic anions as well.

To analyze for calcium or gluconate depends on the sample type. Calcium analysis can be the wrong way if other anions are possible in the sample.

[Rob Burgess]

Looking at the structure of this compound it might even have some sort of UV absorbance down at 210 nm or below.

I wouldnt class this compound as "non-chromophoric". Better to call it a weak chromophore instead.