PPM, PPB

I made a standard curve in ppb.  The results in my summary report will also be in ppb.  Once I calculate my concentration with the weight factored in, (reported conc(ppb) / sample wt. (grams))* final volume, my final result will be in ppm.  Is this correct?

Thanks

No,
you would be in ug/g which is ppb.  You need to be in mg/g for ppm.  Multiply your final result by 1000.

First, a tenet you'll find on this forum is to shy away from the colloquialisms of PPM and PPB, they simply tend to lead us to confusion. If you can, stay with units that are self-defining (ug/L, mg/Kg, etc).

Having said that, if we had to stay with "PPM" and "PPB";

Take a look at "Wikipedia"; http://en.wikipedia.org/wiki/Parts-per_notation.

mg/g would be 1 in 1,000 or 1 X 10-3 which would be parts per thousand (mg/g).

ug/g would be 1 in 1,000,000 or 1 X 10-6 which would be parts per million (or mg/Kg).

ng/g would be 1 in 1,000,000,000 or 1 X 10-9 which would be parts per billion (or ug/Kg).

Greg

Sure, I was merely answering the question stated.

Depending on a specific application calls for certain units.

If you use a lot of NIST SRM's you run into ug/g for example.  I use all forms of units at my job including ug/m3, ug/mL etc...

One needs to be aware of the stoichiometry that presents itself and how to calculate the right concentration units neede for the right application. 

Mik

Thank you very much for your answers.  However, on the contrary, I think using L as the unit for volume would cancel out the L in the reported concentration (which is PPB or ug/L).  Dividing by my sample weight, in grams, will leave me with ug/g which would be PPM.  Forgive me but I am not sure what a mg/g would be in parts.  This is confusing.  Unfortunate for me my data should be expressed in PPM or B.   

MAT:
You are correct that ug/g is "ppm."  mg/g is "parts-per-thousand" as Greg mentioned. 

To avoid confusion, I would report results using ppm (ug/g) or ug/g (ppm) in the heading, so that there is no confusion.

Thanks everybody for the replies.  Sometimes the units even get to the best of us as in this case.

Mik