Question

Question #12905

Answer 1

I'm not sure what you did, but I don’t think it was correct.

Explanation:

First, you prepared a standard curve, in which you plotted the absorbances of known concentrations of the drug.

I presume you got a graph something like this.

You use this plot to determine the concentration of your unknown.

Then you diluted your unknown sample by a factor of 1000 (?).

You measured its absorbance and got a value of 0.247.

From the regression equation, `y = 0.045x + 0.0273`, you get

`x = (y-0.0273)/0.045 = (0.247-0.0273)/0.045 = 0.2197/0.045 = 4.88`

The concentration of the drug in your diluted sample was 4.88 µg/mL.

Thus, the concentration in your original sample was 4.88 mg/mL or 48.8 mg/10 mL.