1.07233

Phenolphthalein

pH indicator, ACS, Reag. Ph Eur

• Synonym(s): Phenolphthalein
• Empirical Formula (Hill Notation): C₂₀H₁₄O₄
• CAS Number: 77-09-8
• Molecular Weight: 318.32
• MDL number: MFCD00005913
• UNSPSC Code: 12171502
• EC Index Number: 201-004-7
• NACRES: NA.21

Properties

• product name: Phenolphthalein, indicator ACS,Reag. Ph Eur
• grade: ACS reagent
• Quality Level: 200
• agency: reag. Ph. Eur.; suitable for SM 2310; suitable for SM 2320
• vapor pressure: <0.00001 Pa ( 50 °C)
• form: solid
• loss: ≤1% loss on drying, 105°C
• color: white to yellow-white
• visual transition interval: 8.2-9.8, colorless to red-violet
• mp: 263.7 °C
• density: 1.296 g/cm³ at 20 °C
• bulk density: 350‑450 kg/m³
• λmax: 551-554 nm (buffer pH 9.8)
• storage temp.: 2-30°C
• InChI: 1S/C20H14O4/c21-15-9-5-13(6-10-15)20(14-7-11-16(22)12-8-14)18-4-2-1-3-17(18)19(23)24-20/h1-12,21-22H
• InChI key: KJFMBFZCATUALV-UHFFFAOYSA-N

Description

Application

• Effectiveness of Phenolphthalein in Sol-Gel Coatings for Sensing and Inhibiting Corrosion on Mild Steel: Research detailing the application of phenolphthalein and Thymol Blue in sol-gel coatings, demonstrating their effectiveness in corrosion inhibition and sensing on mild steel surfaces (Patra et al., 2024).



• Highly Permeable Ultrafiltration Membranes Based on Polyphenylene Sulfone with Cardo Fragments: This article discusses the development of advanced ultrafiltration membranes incorporating phenolphthalein, enhancing their permeability and filtration efficiency (Raeva et al., 2024).



• A fluorescence-based dual sensor for Zn(2+) and PO(4)(3-): Study on a dual sensor system utilizing phenolphthalein, applied for the detection of zinc and phosphate ions in various environmental and biological samples, employing fluorescence signaling (Samanta et al., 2024).

Analysis Note

Identity (UV/VIS-Spectrum): passes test
Appearance: White to yellowish white powder
Clarity of the alkoholic solution (10 g/l ethanol): passes test
Absorption maximum λ_max. (buffer pH 9.8): 551 - 554 nm
Spec. Absorptivity A 1%/1cm (λ_max; 0.01 g/l; buffer pH 9.8; calculated on dried substance): 700 - 750
Transition range: pH 8.2 - pH 9.8 almost colorless - red-violet
Transition range (according to ACS): passes test
Transition interval (according Reag. Ph Eur): passes test
Loss on drying (105 °C): ≤ 1 %

Safety Information

• pictograms: GHS07,GHS08
• signalword: Danger
• hcodes: H315 - H341 - H350 - H361f
• pcodes: P202 - P264 - P280 - P302 + P352 - P308 + P313 - P332 + P313
• Hazard Classifications: Carc. 1B - Muta. 2 - Repr. 2 - Skin Irrit. 2
• Storage Class: 6.1C - Combustible, acute toxic Cat.3 / toxic compounds or compounds which causing chronic effects
• wgk_germany: WGK 3
• flash_point_f: Not applicable
• flash_point_c: Not applicable