I am quantifying paclitaxel on HPLC. I dissolved using two different methods.
1. Pax, SDS, 50:50 water:acetonitrile (no sonication as looked clear)
2. Pax, SDS, 100% acentonitrile (sonicated 1 hour, still looked like particles floating)
Ran HPLC on both. But method 2 gave much higher reading. Appears that sonication is the key to making a difference.
Solution 1 looked completely dissolved to visual eye but appears not to be based on results.
Just wondering if there is any rule of thumb when to sonicate? If I am working with solubilties within the solubility limit for a hydrophobic substance should I just sonicate to be on the safe side all the time?
Thanks for your help:)