How Do I Calculate Se Concentration from Multiple Calibration Curves?

[Beer-monster]

URGENT- Calibration curve question

Okay, so I'm a physicist doing a chem class so I'm a little out of my depth.

I've got a lab report to hand in but I'm a little stuck on the last part, working out the concentration of Se from a calibration curve. My problem is that the calibration curve is against the result from MS analysis, and I have three curves on the graph from 77, 78 and 82 Se, however the x-axis (based on my standards) is the concentration of Se not of the individual isotopes.

How do I work out the concentration of Se in my digest as a whole from the three curves, should I just work out the result from each curve and take and average?

Thanks

 

[GCT]

How do I work out the concentration of Se in my digest as a whole from the three curves, should I just work out the result from each curve and take and average?

I'm not absolutely sure what you're trying to do here. From the mass spectral analysis you should be able to acertain the abundances of the isotopes, your description of the calibration curve is unclear.