Hello. I just wanted to know if anyone knows of any indicator I can use instead of Eriochrome Black T for the detection of calcium. I want to do a comparison of calcium citrate pills vs. calcium carbonate pills. Aside from using Atomic Absorption Spectrometry, I found that titrating calcium with EDTA and using Eriochrome Black T would be just as effective for determining calcium content in the pills. Unfortunately, none of my labs have Eriochrome Black T, which is why I want to know if anyone has any idea on a substitute I can use instead of Eriochrome Black T. Thank you.