Was wondering whether anyone with the knowledge or the availability to find the knowledge could give me a little advice and help obtaining pure sodium nitrite powder in Australia?

I'm looking for a supplier (Preferred not bulk) that can supply it within Australian borders, can mayhaps tell me about import and control regulations within Australia.

Also, with the Sandmeyer Reaction, would potassium nitrite work relatively the same as sodium nitrite, and which changes would occur, what trace chemicals will be left in the conversion to gamma-butyro-lactone?

Pure is best!

Cheers in advance for your help!