Ocean Optics Dragon - Manual (Page 27)

Chapter 4: Experiments
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4. Choose Beer-Lambert Law or Calibration. To use the Beer-Lambert Law option you need to
know the molar extinction coefficient, ε , for the compound you are using. If you are trying to
find ε you need to choose the option “Calibrate from solutions of known concentration.”
5. Wavelength range selection. Quantum needs to know which wavelength to measure for
absorbance. Select one (Lambda max) or a range around Lambda max. You can see the
absorbance spectrum behind the dialog box (the box will move to give you the best view).
However, it is better to check Lambda max before you start the wizard
6. Create the calibration curve. Take at least three samples of known concentration. Either enter
the Absorbance by hand from your notes or scan for it using the Scan now button. When you
enter the third sample a regression line will be plotted. The line can be displayed in first or second
order and forced through the origin. Values for the molar extinction coefficient and R^2 are
calculated.