Chromatography Forum

Hi,
I have some problems with chloride determination
I have Thermo ICS 1100 with 4 mm AS-9HC column.

I have recently analyzed PT from absolute.
I made argentometric titration and IC analysis.
Although I got very good z skor for argentometic analysis, my z skor for IC analysis bad.

I have checked my calibration curve with two different brand of standart sample which also good for titration.

I am very confused now. Anybody having similar problem? or any suggestion?

Please check possible carbonate interference on the collumn, by injecting higher concenration of carbonate.

If you use linear calibration, try to ste caribration curve that the expected result is near to the center of the calibrated range.

Thank you Dr. Markus Laeubli, I tried with high concantrated carbonate and there is a splayed peak at the same point of chloride. I will try to find something about that. do you have any suggestion

I'd either try to acidify (with HNO3, not HCl!) and heat to remove carbonate as CO2. Or precipitate the carbonate and remove by filtration.

Or stick with titration.

Removing CO2 from the sample is not a real solution as then negative signals due to CO2 vacancy may occur.
Best solution would be a column with better chloride/carbonate selectivity or a CO2 suppression device prior to the detector.