Transferrin (T) -

Molar mass = 81000g/mol - carries 2 Fe3+ ions

Deferrioxxamine B (DB)
molar mass = 650g/mol - carries 1 Fe3+

at wavelength 428
molar absorptivity T = 3240
molar absorptivity DB = 2630

at wavelength 470
molar absorptivity T = 4370
molar absorptivity DB = 2190

A solution of transferrin and desferrioxamine was placed in a cuvet with a path length of
1 cm. The absorbance at 470 nm was 0.42, and the absorbance at 428 nm was 0.40.
Calculate the concentration Fe(III) in transferring, assuming each transferrin binds two
Fe(III)

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I calculated concentration for T at both wavelengths using Beers law and added them to find C=2.19*10^-4M

2.19*10-4 M T * 81000 g/mol = 17.739 g/L T

percent mass of Fe3+ in T is

111.69g/81000g *100%= 0.138%

% Fe3+ in 17.739g T = 0.0245g =4.38*10^-4M Fe3+

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I am not sure if this is correct or if I am even on the right track. There is a second part to the question (which is why I wasn't sure if I needed to use all the information given at the beginning). Any help would be great! thank you

1 answer

To the person who posted this question, did you get the right answer? I'm looking for the right answer as well. I'm assuming you were in CHMC11. Did you get the right answer in the quiz/midterm/final? Thanks!