OBJECTIVES
 Make porphyrin solutions with varied SO_{4}^{2} salts
 Take UVVis of varied porphyrin solutions with diluted varied SO_{4}^{2} salts
Porphyrin Salt Selection and Preparations 2
SO_{4}^{2} salts used:Fe_{2}(SO_{4})_{3}, Al_{3}(SO_{4})_{3}, FeSO_{4}, & Na_{2}SO_{4}
Preparing 10mM Stock Solutions For Each Salt :
 Obtain four clean 100mL volumetric flasks with stoppers
 Measure out calculated amounts of each salt to establish 10mM concentration
 Add varied salt amounts to each volumetric flask (one salt per flask)
 Fill each volumetric flask ½ full with HPLC grade H_{2}O
 Swirl each flask thoroughly for ~ 5 minutes to begin the dissolving process
 Finish adding HPLC grade H_{2}O 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 Fe_{2}(SO_{4})_{3} Solution
MW Fe_{2}(SO_{4})_{3}: 278.91 g/mol
10mM Fe_{2}(SO_{4})_{3} × (100mL H_{2}O / 1000mL H_{2}O) × (278.91g Fe_{2}(SO_{4})_{3} / 1 mol Fe_{2}(SO_{4})_{3}) = 0.2789g Fe_{2}(SO_{4})_{3}
 10mM Al_{3}(SO_{4})_{3} Solution
MW Al_{3}(SO_{4})_{3}: 356.37 g/mol
10mM Al_{3}(SO_{4})_{3} × (100mL H_{2}O / 1000mL H_{2}O) × (656.37g Al_{3}(SO_{4})_{3} / 1 mol Al_{3}(SO_{4})_{3}) = 0.6564g Al_{3}(SO_{4})_{3}
MW FeSO_{4}: 278.01 g/mol
10mM FeSO_{4} × (50mL H_{2}O / 1000mL H_{2}O) × (278.01g FeSO_{4} / 1 mol FeSO_{4}) = 0.1390g FeSO_{4}
 10mM Na_{2}SO_{4} Solution
MW Na_{2}SO_{4}: 142.04 g/mol
10mM Na_{2}SO_{4} × (100mL H_{2}O / 1000mL H_{2}O) × (142.04g Na_{2}SO_{4} / 1 mol Na_{2}SO_{4}) = 0.1420g Na_{2}SO_{4}
SO_{4}^{2} Salts Selected

Salt Mass Needed (g)

Actual Salt Mass (g)

HPLC Grade H_{2}O Added (mL)

Total Concentration(mM)

Fe_{2}(SO_{4})_{3} 
0.2879 
0.3100 
100 
10

Al_{3}(SO_{4})_{3} 
0.6564 
0.6556 
100 
10

FeSO_{4} 
0.1390 
0.1394 
100 
10

Na_{2}SO_{4} 
0.1420 
0.1464 
100 
10

UVVis Spectrum of Porphyrin with Salts 2
Notes
 The Al_{3}(SO_{4})_{3} 10mM solution was very opaque and cloudy with some precipitate slightly falling out of solution. Before using the Al_{3}(SO_{4})_{3} solution, it had to be swirled to ensure that all precipitate was in solution.
 Also for the FeSO_{4} 10mM salt solution, it was prepared in a 50mL volumetric flask instead of a 100mL volumetric flask.
 Also for the 10mM salt solutions of Fe_{2}(SO_{4})_{3} and Na_{2}SO_{4}, 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 H_{2}O to produce the 10mM salt solution of each substance.
