Looking to test the ppm for lead in a powder that is a food item. No experience in chemistry. Possibly may need to test for other heavy metals.
Google is your friend. You are in Canada, so I'm uncertain if your regular pharmacies carry such kits (many of ours do in the US).
Start with home kits - they have you mail-in a specimen - and graduate if needed based on LDL (lower detection limits).
You should be able to get a good idea (maybe binary) about contaminants, which you can then follow-up with more expensive but very worthwhile tests involving more advanced analytical techniques.