Anybody feel that the vape carts may be causing failing heavy metals testing?

So when a lab receives vape carts to sample from, the techs need to get the liquid out somehow and I have seen a few methods of doing this but I can’t help but to think that any scraping of the inside of the carts may introduce unwanted heavy metals into the concentrate.

Also, maybe the carts themselves contain heavy metals that will naturally leech into the concentrate. If so, do terpene concentrations affect this?

Lots to think about. What are your thoughts?