Iron tablet titration

Jan 2017
1
0
Colombia
Hello, i am new here and i am having problems with a redox titration lab i would really appreciate if someone can help me see what could explain the flaws of the method i used.
In my lab practice i was trying to analyse how much iron there was in an iron tablet compared to the actual value it had. For this i made an acidified solution with sulfuric acid and the pills and titrated it with potassium permanganate. The main problem i had was the initial colour of my solution, since the iron tablet was pink the solution also became pink. When i started the titration the pink colour decolorized and the solution became completely transparent, so i record this value and kept titrating until the solution acquired a faint pink colour. Therefore i compared my results and my method with some that i coloud find online, eventhough those i found had a low percentage of error their initial solution was transparent and the end point was reached when became pale pink.
I tried coming for an to this problem and i think that is mainly because of the initial color of the solution, i think that the folic acid and the dye they used on the pill might have beem oxidized bu the permanganate and this gave me a higuer value than expected. However i dont know if this assumptipn is right or to flawded. Thanks again.