I am attempting to sponatenous plate on silver Polonium present in digested mineral samples. I need the solution to be at a pH of about 0.5-1 and at a temperature of about 90°C.

Testing the method with just HCl, and very small amount of a standard solution of polonium and ascorbic acid, a dark fine grained precipitate and the solution turns peach coloured.

I use about 15ml of 1M HCl and 400mg of ascorbic acid. I am unsure what does precipitate or why that happens. The standard solution should be relatively free of contaminants and the amount of precipitate is quite visible and therefore not trivial.

I hope someone can give me some idea of what might be happening!

Many thanks,