Electronic Grade DL-Tartaric acid CSA 133-37-9

DL‑Tartaric Acid (chemical formula: C₄H₆O₆, CAS Number: 133‑37‑9), also known as racemic acid, is a racemic mixture of D‑tartaric acid and L‑tartaric acid. It is a versatile organic dicarboxylic acid presented as colourless transparent crystals or white crystalline powder, featuring strong acidity, excellent chelating capacity and good water solubility. DL‑Tartaric Acid serves as a vital acidulant, sequestering agent and chemical intermediate widely applied in food‑beverage, pharmaceutical, electroplating, textile and fine‑chemical industries.

Basic Chemical Identifiers

• Common Name: DL‑Tartaric Acid, Racemic Acid
• IUPAC Name: 2,3‑dihydroxybutanedioic acid
• CAS No: 133‑37‑9
• EINECS No: 205‑105‑7
• Molecular Formula: C₄H₆O₆
• Molecular Weight: 150.09 g/mol
• HS Code: 29181200

Physical Properties

• Appearance: Colourless prismatic crystals or white crystalline powder, odourless with sharp sour taste
• Density: 1.788 g/cm³
• Melting Point: 206‑212 °C (decomposes upon heating)
• Boiling Point: 399.3 °C at 760 mmHg
• Flash Point: 210 °C
• Solubility: Freely soluble in water and ethanol; slightly soluble in ether; insoluble in benzene and chloroform
• Optical Rotation: No optical activity (racemate)
• pKa: pKa₁=3.03, pKa₂=4.37 (25 °C); aqueous solution shows strong acidity
• Stability: Stable under normal ambient conditions, non‑hygroscopic

Chemical Properties

DL‑Tartaric Acid contains two carboxyl groups and two hydroxyl groups, enabling typical carboxylic‑acid and poly‑alcohol chemical behaviours. It readily reacts with alkalis to generate various tartrate salts, and forms stable chelate complexes with metal ions such as Ca²⁺, Fe³⁺, Cu²⁺. DL‑Tartaric Acid demonstrates antioxidant synergistic effect. It decomposes above 210 °C, producing small‑molecule organic fragments and carbon dioxide. It does not show optical rotation due to equal D‑ and L‑isomer content.