Methylene Blue

C16H18ClN3S·3H2O 373.90
Phenothiazin-5-ium, 3,7-bis(dimethylamino)-, chloride, trihydrate.
C.I. Basic Blue 9 trihydrate [7220-79-3]
Anhydrous 319.86 [61-73-4]

Methylene Blue contains not less than 98.0 percent and not more than 103.0 percent of C16H18ClN3S, calculated on the dried basis.
Identification: Infrared Absorption 197K .