Calculate conc h2so4,acid base titration of h2so4?

my h2so4 contain lot of Fe on it. i have naoh to titrate with h2so4 but it forms precipitate of Fe2O3 before i reach the end point. which base can i use to titrate with h2so4?since this is more like complex titration can i use edta as my primary standard? if yes what will be the reaction?i need the concentration of h2so4 in the solution. please help.