[targe]

 I will be making a calibration curve on a GC-MS and need to get a sample down to 500, 200, 100, 50, and 20 PPB.  The sample has a specific gravity of 1.145 and will be in Ethyl Acetate. Does anyone know how to go about doing the math for this?

I know that in water you can put .001 mL of sample into 1000 mL of water to get 1 PPM, but I don't know how to go about getting it in ethyl acetate.

The units at the end end up being ng/mL

[Borek]

I know that in water you can put .001 mL of sample into 1000 mL of water to get 1 PPM, but I don't know how to go about getting it in ethyl acetate.

Hint: this is correct assuming density of both the sample and solution is 1 g/mL.

Which is already based on another assumption: that you use ppm (ppb) defined as mass/mass. This is the most common way of using ppx to denote concentration, but not the only one.

Compare https://www.chembuddy.com/concentration-ppm-ppb-ppt