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Where can I purchase sodium orthophosphite

2007

Q. To Whom it may concern,

I am a MSc. student in Imperial College London. I would like to get your assistance with something please?

I am carrying out some kinetic and parametric studies on spent electroless nickel plating baths. I would like to electrodeposit the spent solution in a moving bed electrode setup.

I am trying to simulate spent plating bath conditions with citrate as buffer and stabliser. I am using Nickel Sulphate as my nickel source and I need a source of ortho-phosphite. Short of carrying out an EN process can anybody recommend somebody I can purchase some sodium orthophosphite from? I have tried Sigma and JT Baker but they don't seem to have ortho or dihydrogen phosphite in their online or manual indexes.
If at all possible I would like to get a CAS number?

Thank you for your help.

Brendan Wallace

Brendan John Wallace
MSc. Student - London, England

"Electroless Plating"
by Mallory & Hajdu

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A. If you want my advice ...

Don't waste time by messing around with "simulated" waste. Find some real EN waste, characterize it as best as you can, then do your experiments on that.

Dave Wichern
Consultant - The Bronx, New York

A. Don't know any vendor for sodium orthophosphite. Make your own by oxidizing sodium hypophosphite in aqueous solution (similar to orthophosphite formation during EN). Adding hydrogen peroxide (careful, a vigorous reaction):
2 NaH2PO2 + H2O2 = 2 NaH3PO3

Follow the course of the reaction via ORP during the peroxide addition. Basically a redox titration; the ORP will change from about an initial -500 mV @ pH 5 to 0 mV at the finish. Avoid using an excess of peroxide; phosphate may form.
CAS Nos. for sodium hypophosphite: 7681-53-0 (Anhydrous); 10039-56-2 (Monohydrate).

Ken Vlach [deceased]
- Goleta, California

Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.

A. Just a thought. Wouldn't it be much easier to ask for spent solution from a EN vendor? Then you can analyze and characterize it before using it in your experiment. I'm sure there will be platers in your area willing to give you any amount you will ever need.

Guillermo Marrufo
Monterrey, NL, Mexico

2007

Dear responders,

Thank you very much for getting back to me with your advice and information.

Best Regards,

Brendan John Wallace
- London, England

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