I trying to figure out how to obtain the concentration my result in mg/ml in a typical swab cleaning analysis.

Let's say

Area sample peak = 100

Area standard peak = 25

Weight of standard = 25 mg

Dilution vol of standard = 100 ml

Dilution vol of swab = 15 ml

Therefore

Conc. = (100/25) x (25mg/100ml) x (15ml/1 swab) = 15 mg/swab

Is this correct? I want to obtain conc. in mg/ml not mg/swab. How would I get mg/ml?

So looking at your problem and at your formula. If you wanted to have the concentration of mg/mL, all you would have to do is not convert to swab.

So all you would have to do is :

100/25 x 25mg/100mL = 1 mg/mL

25mg/100mL is the concentration of your standard, which is 0.25mg/mL and your sample has 4 time the area, which means 1mg/mL

Not sure if that answers your question?