User:Karlena L. Brown/Notebook/PVOH Research/2012/10/26

OBJECTIVES

• Make porphyrin solutions with varied SO₄^2- salts
• Take UV-Vis of varied porphyrin solutions with diluted varied SO₄^2- salts

Porphyrin Salt Selection and Preparations 2

SO₄^2- salts used:Fe₂(SO₄)₃, Al₃(SO₄)₃, FeSO₄, & Na₂SO₄

Preparing 10mM Stock Solutions For Each Salt :

1. Obtain four clean 100mL volumetric flasks with stoppers
2. Measure out calculated amounts of each salt to establish 10mM concentration
3. Add varied salt amounts to each volumetric flask (one salt per flask)
4. Fill each volumetric flask ½ full with HPLC grade H₂O
5. Swirl each flask thoroughly for ~ 5 minutes to begin the dissolving process
6. Finish adding HPLC grade H₂O to each volumetric flask to line

(Ensure that the volumetric calibration line is not surpassed or solution must be remade.)

10mM Salt Solution Calculations

• 10mM Fe₂(SO₄)₃ Solution

  MW Fe2(SO4)3: 278.91 g/mol
  10mM Fe2(SO4)3 × (100mL H2O / 1000mL H2O) × (278.91g Fe2(SO4)3 / 1 mol Fe2(SO4)3) = 0.2789g Fe2(SO4)3
 

• 10mM Al₃(SO₄)₃ Solution

  MW Al3(SO4)3: 356.37 g/mol
  10mM Al3(SO4)3 × (100mL H2O / 1000mL H2O) × (656.37g Al3(SO4)3 / 1 mol Al3(SO4)3) = 0.6564g Al3(SO4)3
 

• 10mM FeSO₄ Solution

  MW FeSO4: 278.01 g/mol
  10mM FeSO4 × (50mL H2O / 1000mL H2O) × (278.01g FeSO4 / 1 mol FeSO4) = 0.1390g FeSO4
 

• 10mM Na₂SO₄ Solution

  MW Na2SO4: 142.04 g/mol
  10mM Na2SO4 × (100mL H2O / 1000mL H2O) × (142.04g Na2SO4 / 1 mol Na2SO4) = 0.1420g Na2SO4
 

UV-Vis Spectrum of Porphyrin with Salts 2

Notes

• The Al₃(SO₄)₃ 10mM solution was very opaque and cloudy with some precipitate slightly falling out of solution. Before using the Al₃(SO₄)₃ solution, it had to be swirled to ensure that all precipitate was in solution.
• Also for the FeSO₄ 10mM salt solution, it was prepared in a 50mL volumetric flask instead of a 100mL volumetric flask.
• Also for the 10mM salt solutions of Fe₂(SO₄)₃ and Na₂SO₄, these solutions were actually prepared through the process of dilution in conical test tubes. 1mL of the 100mM salt solution for each substance was taken and diluted with 9mL of HPLC grade H₂O to produce the 10mM salt solution of each substance.