Cresol Red/o-Cresolsulfonphthalein；4,4'-(3H-2,1-Benzoxathiol-3-ylidene)bis(2-methylphenol) S,S-dioxi

English Name: cresol red; o-Cresolsulfonphthalein； 4,4'-(3H-2,1-Benzoxathiol-3-ylidene)bis(2-methylphenol) S,S-dioxide

Other names: o-cresol red; O-cresol sulfonyl phthalide; O-cresol sulfonphthalein; O-methylsulfonphthalein; O-cresol sulfonphthalein

CAS No.: 1733-12-6

C21H18O5S=382.43

Grade: ind

PH discoloration range: 6.5 (yellow) ～ 8.5 (purple)

Maximum absorption wavelength λ 1(pH 6.5)：432～436 nm

Maximum absorption wavelength λ 1(pH 8.5)：571～574 nm

Mass absorption coefficient α 1( λ 1, pH 6.5, dry sample): 49.0 ～ 67.0l/cm · G

Mass absorption coefficient α 2( λ 2, pH 8.5, dry sample): 100.0 ～ 132.0l/cm · G

Loss on drying: ≤ 3.0%

Burning residue (calculated by sulfate): ≤ 0.2%

Ethanol dissolution test: acceptable

Physicochemical properties: reddish brown crystalline powder. Soluble in ethanol, water, dilute acid (yellow) and dilute alkali (purple). Its 0.1% ethanol solution or 0.04% sodium salt solution was used as an indicator

Purpose: biochemical research. Acid base indicator, pH 7.2 (yellow) ～ 8.8 (purple); PH 2.0 (Orange) ～ 3.0 (Amber).

Saving: RT