Cleavage of phosphate ester bonds by phytase leads to dephosphorylated T-phosphatidylinositol intermediates that may be quantified using reversed phase chromatography with UV detection. Exists as the decaammonium salt. For the free pentaacid, MF = C₁₉H₃₄NO₂₂P₅ and MW = 783.42. Covered under U.S. Patent NO. 7,741,5061. See: Berry, D. F.; Berry, D. A. Tethered phytic acid as a probe for measuring phytase activity. Bioorg. Med. Chem. Lett. 2005, 15(12), 3157-61.