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Analyzing Ni and Au of electroless Ni, immersion Au bath

2002

Hello, friends,

I'm going to handle the electroless nickel & immersion gold process in my company. But, I'm still facing some problem to analyze the Ni content & gold content in the plating bath. Could somebody suggest me some methods to analyze the Ni & Au content of this plating bath?

Thank you very much in advance for your helpfulness!

Regards,

Wymen Lee
- Penang, Malaysia

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2002

The chemical analysis of nickel in EN is similar to that in electroplating. You will have to change the volume of sample and the strength of titrant. The following procedures are for nickel in EN that contains no other metals.

1. Pipet 10 ml of sample into a flask (I like Erlenmyer).
2. Add 100 ml of deionized water.
3. Add 10 ml of concentrate NH4OH (pH should be at least 10).
4. Add 2 g of 0.2% murexide [affil links] indicator. Swirl gently.
5. Titrate immediately with 0.2 N (0.1 M) EDTA.

Ni (g/l) = 0.587*ml of EDTA

There are slight variations of this method. Some use more NH4OH. Some use pH 10 buffer. Some add triethanolamine. You might want to make up a solution of known nickel content and then try it.

Good luck.

Kai Lorcharoensery
Lehigh University - Bethlehem, Pennsylvania, USA

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2002

Dear Mr. Lorcharoensery,

Thank you very much for the info. Unfortunately, murexide [affil links] is banned chemical(Poison) in Malaysia here. I've discussed with our chemical suppliers and they said it's impossible to have this chemical in Malaysia. It's against our law here. Anyway, thanks for your help. Is there any others method beside this titration?

Best Regards,

Wymen Lee
- Penang, Malaysia