From https://doi.org/10.1039/C9JA00283A, it looks like the ingredients list for standard reference e-waste goes:

Copper, Aluminum, Iron, Selenium, Zinc, Silicon, Antimony, Lead, Barium, Nickel, Chromium, Silver, Gold, Arsenic

Throw some Carbon, Nitrogen, Oxygen, Hydrogen, and a few other trace elements for the plastics too.