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Titration procedure for Chlorides in an Anodize Tank?

I have no idea on how to find out the amount of chlorides that are present in my anodize tank or my other tanks. Can someone guide me in the direction to find this out? Also is there a way to remove the chlorides without having to dump my tank? I plan on getting a RO/DI system asap but I need to fix this problem first. Thanks for the help.

Ryan Zettlemoyer
Plating shop employee - Gainesville, Florida
February 13, 2008

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Ryan,

It will depend on how well equipped your Lab is for the technique you can use.

If you have ion selective capabilities then you could titrate with silver nitrate [on eBay or Amazon] to the equivalence point.

If not you are probably looking at a gravimetric method of analysis. This involves precipitating silver chloride from solution, filtering off the precipitate and then weighing. Unfortunately this method is often inaccurate.

As for trying to rescue a chloride contaminated bath, I wouldn't bother, make up a fresh solution and ensure that you do not have chlroide contamination.

Brian Terry
Aerospace - Yeovil, Somerset, UK
February 19, 2008

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Hi
You can find something to read in
VOLUMETRIC ANALYSIS OF METAL FINISHING SOLUTIONS FOR ANDREW MCFADYEN
Page 5, determination; Chloride in anodizing solutions

Fausto Cabrera
- Santiago, Dominican Republic
February 21, 2008

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Hello Ryan,
Titration of chloride containing solution with Potassium Chromate as internal indicator against Std Silvernitrate solution is a simple method.
Ramajayam

Subramanian Ramajayam
consultant - Bangalore, India
January 11, 2009