Supressing Cl ions from evaporating in HF

[joelyue]

Hi,

i am trying to quantify trace Cl in HF acid using an Ion Chromatography system. However when doing a recovery, i find that all the Cl ions is lost when i evaporated the HF acid.

Does anyone know of any chemical which i can add to prevent the loss of Cl ions while still eliminating the F ions which upset the accuracy of the chromatogram?

[HW Mueller]

To where do you evaporate HF (are you really talking about hydrofluoric acid?).
These old ion assays, which are usually quite a bother for general chemistry students, might work. Don´t remember if a reaction of F- with AgNO3 was mentioned.

[joelyue]

Yes when i mentioned HF i do mean Hydroflouric Acid.

I usually evaporate the HF in a fume chamber. The HF fumes are then sucked into the exhaust system and scrubbed by a scrubber before releasing into the atmosphere.

[HW Mueller]

Just wonder how the HF is scrubbed. Maybe you can use that technique to get at the Cl-?