User:Alex Lutz/Notebook/Experimental Chemistry - 481/2018/09/05

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Redo the standard curve for the Malachite green absorption and measure the fluorescence curve for Rhodamine B.


  1. Measure UV-Vis spectrum of different malachite solutions.
  2. Create 2 new solutions using available stock solutions.
  3. Plot the data and determine extinction coefficients.

Procedure for fluorometer

  • Fluorescence spectrometry is also a non-damaging technique meaning that that samples can be returned to their containers after testing.
  1. After cleaning the cuvette (this is done the same way as for the UV-Vis), add the sample to fill about 75% full.
  2. Insert the cuvette into the fluorometer.
  3. After saving as a .txt file to be exported, remove the cuvette from the fluorometer and return the sample to the container.


  1. Stock solutions of Malachite green
    1. .309 ppm
    2. 1.0 ppm
    3. 1.5 ppm
    4. 5.917 ppm
  2. Newly created stock solutions
    1. 6.7 ppm (3.160g of 106 ppm Malachite green stock, water added to a total mass of 50.008g)
    2. 8.8 ppm (3.8277g of 106 ppm Malachite green stock, water added to a total mass of 45.659g)

The new standard curve for Malachite green

  1. Stock solutions for the Rhodamine B
    1. 66.4 ppb
    2. 164 ppb
    3. 287 ppb
    4. 332 ppb
    5. 746 ppb

  • Absorption vs wavelength of Rhodamine B

  • Areas under the curve for each wavelength were calculated and graphed vs the relative concentration for Rhodamine B:


  • Parameters Used:
    • Start(nm): 565 End(nm): 700 Excitation(nm): 555
    • Ex slit(nm): 5 Em slit(nm): 50 Scan Speed(nm/min): 200