Physical state, solid.
1 percent solution in chloroform, clear.
Melting point (decomposition), 136 °C.-140 °C. (corrected).
Loss of weight on drying, not more than 0.2 percent.
Residue on ignition, not more than 0.2 percent.
Lead (as Pb), not more than 10 parts per million.
Arsenic (as As), not more than 1 part per million.
Assay (spectrophotometric), 96-101 percent.
21 C.F.R. §73.90