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

Meta-CRESOL PURPLE FREE ACID

Synonyms:				m-Cresolsulfonephthalein

CAS No:				2303-01-7

Chemical Formula:			C21H18O5S

Formula Weight:			382.43

Description:				Reddish Brown to Green to Olive Green Powder

Indentification (IR):		Conforms to standard

Visual Transition Intervals:	pH 1.2 (red) to pH 2.8 (yellow)
pH 7.4 (yellow) to pH 9.0 (purple)

Loss on drying:			1.5% maximum

Assay:					90.0% minimum

Lambda Max:			579(371)nm in 0.005N Sodium 
Hydroxide in Methanol

Solubility:				Clear
(0.1% in 50% Methanol)				
					Very slightly soluble in water and ethanol,
and soluble in methanol and acetic acid.	

Effective: 08/01/18