[Jotach]

Hi!

Last we tried to find the concentration of Mn in an alloy based on spectroscopy.

Now we found the absorbance relative to the blank from the standard solution (0.24) and the absorbance relative to the blank from the unknown solution (0.26).

We also made a calibration curve based on the standard solution (A(c) = -0,04 + 2350*c )

Now we're wondering how we have to calculate the concentration of the unknown solution, should we use 0.24 or 0.26 or should we use the difference between the two absorbances to make an new relation between A and c?

thanks!

[chenbeier]

How do you made the calibration curve?
What is the concentration of your standard?
According the values of absorbance, the concentration of unknown sample is a little higher as your standard.
If the formula is correct calculate with 0,26 for sample. 0,24 should give your standard concentration.

[Jotach]

The calibration curve is based on different solutions of the standard (4.0E-3 M)

[Corribus]

Why does your blank have lower absorbance than your first few standards?