CAS# 67-43-6. 250g. Diethylenetriaminepentaacetic acid, 98.5% DTPA (USP). MFCD00004289. Molecular Weight: 393.35. Molecular Formula: (HO2CCH2)2N(CH2)2N(CH2CO2H)(CH2)2N(CH2CO2H)2. Color/form: white xtl. Strem# 07-0398. http://www.strem.com/catalog/v/07-0398/