No, it does not work like that.
98%+ pure might as well mean 100%, but I steer away from stating it like that due to the fact that it's impossible to distinguish minute impurities and electronic noise. It's generally done that way in the industry for routine tests.
I've had a lot of discussions on the topic of heavy metals before.
One on SST just a day or so ago, one over here, not so long ago as well:
Heavy metals
No, you interpreted it wrong, it doesn't mean that at all. It just means it's compatible with solvents used in that application.
No, ICP-MS which is used for heavy metals in blood does them all at once and no, they don't need more than a single draw.
Don't post misinformation.