Sodium tartrate

Sodium tartrate (CAS 868-18-8), also known as disodium tartrate or sal tartar, is the disodium salt of tartaric acid. It carries the molecular formula C4H6O6.2Na and is commercially available under several synonyms including sodium L-tartrate and sodium DL-tartrate. It does not hold an assigned E-number in the EU.

In pharmaceutical formulations, sodium tartrate acts as a buffering agent, stabilising pH in injectable preparations and oral solutions through its weak acid-salt equilibrium. In food processing, it functions as a sequestrant, binding divalent metal ions such as calcium and iron to prevent oxidative discolouration and rancidity. It also serves as a mild acidulant in flavour systems.

Sodium tartrate is available in food-grade and pharmaceutical-grade forms, with quality benchmarks including FCC and Ph.Eur. specifications. It is subject to REACH registration requirements for EU supply. Typical packaging formats include 25 kg bags and fibre drums.