[Archer]

Hi Everyone, I am new here and I really hope that someone can help me as I have poured over loads of books and had many fruitless internet searches.

I am looking for a qualitiative method for red phosphorus, ideally I would like to it be quantitiative but I suspect that this will require specialist equipment. Please note that most internet searches have come up with results for phosphate or phosphorus in soild (which I very much doubt is elemental phosphorus)

I have a sample of suspected red phosphorus but the best I can come up with is to burn it, collect the smoke in water, neutralise it with base and measure the phosphate content of the water, this is not particularly scientific and I have seen videos of phosphorus fire. This is far from ideal as I also don't want to start a fire in the laboratory.

Does anyone have a reliable colourmetric method for Red P, or a reliable method for oxidising Red P in aqueous solutions (i.e. no fire).

Any help / advice would be greatly appreciated.

[Stepan]

You can sublimate a few mg of P(red) in a tube with closed ends (something like a small test tube) made of Al foil. When it condenses on cold part of the foil, it forms P(white), which is pyrogenic at room temperature, and slowly burns with weak, pale white light (visible in complete darkness).  If you observed this reaction, your sample contains P(red). Do not take more than a few mg of sample for this test.