Uracil, C4H4N2O2—112.09—White to cream-colored,crystalline powder.Melts above 300
.One g dissolves in about 500mLof water;less soluble in alcohol;soluble in ammonia TSand in sodium hydroxide TS.Its solutions yield no precipitate with the usual alkaloidal precipitants.
Residue on ignition(Reagent test):
negligible,from 100mg.
Loss on drying á731ñ—
Dry it at 105for 2hours:it loses not more than 2%of its weight.
for 2hours:it loses not more than 2%of its weight.
Uranyl Acetate (Uranium Acetate), UO2(C2H3O2)2·2H2O—424.15—Use ACSreagent grade.
Urea, NH2CONH2—60.06—Use ACSreagent grade.
Urethane (Ethyl carbamate), C3H7NO2—89.09—White powder with chunks.Freely soluble in water.
Uridine, C9H12N2O6—244.20—White powder.
Assay—
MOBILE PHASE—
Prepare a mixture of methanol and 0.2Mammonium acetate (90:10),and adjust with phosphoric acid to a pHof 7.0.
TEST SOLUTION:
0.5mg per mL.
PROCEDURE—
Inject about 20µLof the Test solutioninto a liquid chromatograph (see Chromatography á621ñ),equipped with a 280-nm detector and a 4.6-mm ×15-cm column that contains packing L1.The flow rate is about 2.0mLper minute.The area of the C9H12N2O6peak is not less than 99%of the total peak area.