Alizarin Red S Mono Sodiumsalt (C.I. 58005), Analysis and Indicator, Merck KGaA (CAT#: STEM-L-1194-LKN)

The Alizarin Red S Mono Sodiumsalt (C.I. 58005) from Merck KGaA is used for analysis and indicator.

Analysis Notes:
Identity (UV/VIS-Spectrum): passes test.
1st transition range: pH 4.3 - pH 6.3 Lightly yellow - pink.
2nd transition range: pH 9.4 - pH 12.0 Brown orange - violet.
Absorption maximum λ 1 (buffer pH 4.3): 418 - 424 nm.
Absorption maximum λ 2 (buffer pH 6.3): 510 - 517 nm.
Absorption maximum λ 3 (buffer pH 9.4): 444 - 450 nm.
Absorption maximum λ 4 (buffer pH 12.0): 554 - 558 nm.
Spec. Absorptivity A 1%/1cm (λ1max; 0.01 g/l; buffer pH 4.3; calc. on dried substance): 135 - 180.
Spec. Absorptivity A 1%/1cm (λ2max; 0.01 g/l; buffer pH 6.3; calc. on dried substance): 145 - 210.
Spec. Absorptivity A 1%/1cm (λ3max; 0.01 g/l; buffer pH 9.4; calc. on dried substance): 170 - 230.
Spec. Absorptivity A 1%/1cm (λ4max; 0.01 g/l; buffer pH 12.0; calc. on dried substance): 340 - 520.
Loss on drying (110 °C): ≤ 10 %.

InChI key: HFVAFDPGUJEFBQ-UHFFFAOYSA-M.
Storage conditions: Store at +5°C to +30°C.