TEHP, in an equal volume of diethyl ether, is shaken with aqueous 5% HCl, and the organic phase is filtered to remove traces of pyridine (used as a solvent during manufacture) as its hydrochloride. This layer is shaken with aqueous Na2CO3, then water, and the ether is distilled off at room temperature. The ester is then filtered, dried for 12hours at 100o/15mm, and again filtered, then shaken intermittently for 2days with activated alumina (100g/L). It is decanted through a fine sintered-glass disc (with exclusion of moisture), and distilled under vacuum. [French & Muggleton J Chem Soc 5064 1957.] *Benzene can be used as a solvent (to give 0.4M solution) instead of ether. IR (): 1702, 1701, 481 and 478cm -1 [Bellamy & Becker J Chem Soc 475 1952]. The uranyl nitrate salt is purified by partial crystallisation from hexane [Siddall & Dukes J Am Chem Soc 81 790 1959, Siddall J Am Chem Soc 81 4176 1959]. [Beilstein 1 IV 1786.]