which orange juice has more vitamin c?

[deleted-394368]

My 7th grade daughter is doing a project on which orange juice has the most vitamin c by way of titration. She wants to know if she can use the Equate: Providine-Iodine solution, 10%, instead of the Lugol's iodine. we have already spent too much money on this project, the Lugol's can only be purchased on line more money, so what other iodine solution can we buy that wed can get locally at the store like Walmart or target or Kmart. Please help!!!!!