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1. Introduction          2. Learning objectives     3. History 

4. Basic Principles    5. Detection Methods      6. Chromatograms

7. Instrumentation    8. Experiments                9. Troubleshooting
 

 

Chromatograms Part III


 
After considering the prior question:  Since we are concerned with the concentration of ions present in the solution, how will the chromatogram change as you increase the amount of analyte loaded onto the column?

 
The chromatogram peak will increase in height and concamitantly in area.  Therefore when quantifying data, the peak height or area is used.  In order to determine actual concentrations, a series of standards must be analyzed to calibrate the response between peak area and actual concentration for each ion. 

 
An example chromatogram of Poland Springs bottled water.  Each separate peak is due to a different cation.

 Cation Chromatogram of poland springs bottled water
The area under each peak is used to calculate the concentration of each ion.   What information would you need in order to determine the relationship between peak area and concentration?

 
Just like any other quantitative method, you need to calibrate the response, in this case by analyzing a series of known standards and plotting a calibration curve.
 
If you notice, the last peak is not completely guassian, there are other factors that do have an impact on peak shapes.  For more in-depth information on peak shape, see the following material (link is to an external website).

 
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