S P E C I F I C A T I O N S

BENZOPURPURIN 4B

Synonyms:				C.I. 23500; Direct Red 2

CAS No.:				992-59-6

Chemical Formula:			C34H26N6Na2O6S2

Formula Weight:			724.73

Appearance:				Dark Red to Reddish –Brown Powder

Absorption Maximum:		480-495.0 nm
(In pH 4.4 buffer Solution)

Absorbance at 4.4 Buffer:		Min 0.650 (20mg/L, pH4.4 Buffer
Solution 480.0 to 495.0 nm             solution 480.0 to 495.0 nm

Loss on Drying:			3% Maximum

Visual Transition Interval:	From pH 1.3 (Blue-Violet)
					To      pH 4.0 (Red)

Solubility (20mg/ml H2O):		Clear dark red solution

Effective Date: 07/19/19