Hello Everyone-

 

I have been seeking the answer to the following many places on the internet, but am having trouble finding it and am hoping someone here can help.

 

I have 1 gram of gold, the particles of which are 100 nanometers in size. I am trying to find out the following:

 

If I wanted to make a suspension of gold in water so it will turn out to be 100 PPM, how do I go about figuring out how much weight of the gold nanoparticles to add to the water to achieve that PPM rate?

"Parts per million" isn't a good measure here. I assume you mean each "100 nanometer" piece to be a "part" of gold but what is a "part" of water? You would be better of calculating density in terms of grams of gold per gram of water.

Smells like colloidal gold...

After doing a lot more research, doing all kinds of formulations to do with volume, mass, etc., I think we finally figured out that PPM, being mg/l, is simply weighing the substance and adding it to a liter of water. So if we wanted a 200PPM suspension, we add 200 mg to a liter of water. I think we thought it couldn't possibly be that simple, but I think we were wrong.... it is that simple!