Does baking soda contain phosphorus

No, you can't. There is no Phosphorous (P) in water (H2O) or baking soda (NaHCO3) at all.

Phosphorus was originally discovered as a result of, basically, boiling down urine (alchemists got up to some wacky stuff; the guy who discovered it was hoping for gold... well, it's kind of the same color, don't look at me like that), so the basic principle isn't entirely crazy, it's just that it won't work with those particular ingredients.

And before you try his method: let me warn you it's going to stink to high heaven, and it takes a couple hundred gallons to get an ounce of phosphorus.