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1.06076

Supelco

Methyl red (C.I. 13020)

pH indicator, ACS, Reag. Ph Eur

Synonym(s):

Methyl red (C.I. 13020), 4-Dimethylaminoazobenzene-2′-carboxylic acid

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About This Item

Empirical Formula (Hill Notation):
C15H15N3O2
CAS Number:
Molecular Weight:
269.30
MDL number:
UNSPSC Code:
12352107
EC Index Number:
207-776-1
NACRES:
NA.05

product name

Methyl red (C.I. 13020), indicator ACS,Reag. Ph Eur

grade

ACS reagent

Quality Level

agency

reag. Ph. Eur.
suitable for SM 4500 - NH3

form

powder
solid

loss

≤5% loss on drying, 110°C

color

red to red-violet

visual transition interval

4.4-6.0, red to yellow

mp

178-182 °C

bulk density

300‑500 kg/m3

Amax

427-437 nm (buffer pH 6.2)
523-526 nm (buffer pH 4.5)

storage temp.

2-30°C

InChI

1S/C15H15N3O2/c1-18(2)12-9-7-11(8-10-12)16-17-14-6-4-3-5-13(14)15(19)20/h3-10H,1-2H3,(H,19,20)

InChI key

CEQFOVLGLXCDCX-UHFFFAOYSA-N

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Analysis Note

Identity (UV/VIS-Spectrum): passes test
Appearance: Red to red-violet powder, eventually with granular parts.
Clarity of solution (1 g/l; ethanol): passes test
Melting point (capillary method, temperatur measerment in the heating block): 179 - 182 °C
Transition range: pH 4.4 - pH 6.0 Red - yellow
Absorption maximum (buffer pH 4.5): 523 - 526 nm
Absorption maximum (buffer pH 6.2): 427 - 437 nm
Spec. Absorptivity A 1%/1cm (λmax; 0.005 g/l; buffer pH 4.5; calculated on anhydrous substance): 1350 - 1500
Spec. Absorptivity A 1%/1cm (λmax; 0.005 g/l; buffer pH 6.2; calculated on anhydrous substance): 700 - 800
Transition range (according to ACS): passes test
Loss on drying (110 °C): ≤ 5 %

Storage Class

11 - Combustible Solids

wgk_germany

WGK 2

flash_point_f

Not applicable

flash_point_c

Not applicable


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