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25508 Sigma-Aldrich

Potassium sodium tartrate tetrahydrate

puriss., 99.0-101.0% (calc. on H2O free substance), meets analytical specification of Ph. Eur., BP, USP, FC, E 337

Synonym: L(+)-Tartaric acid potassium Sodium salt, Rochelle salt, Seignette salt

  • CAS Number 6381-59-5

  • Linear Formula KOCOCH(OH)CH(OH)COONa · 4H2O

  • Molecular Weight 282.22

  •  Beilstein Registry Number 6113568

  •  EC Number 206-156-8

  •  MDL number MFCD00150989

  •  PubChem Substance ID 57648125



Related Categories Essential Chemicals, Potassium Salts, Research Essentials, Salts
grade   puriss.
assay   99.0-101.0% (calc. on H2O free substance)
optical activity   [α]20/D +28.0 to +30.0°
quality   meets analytical specification of Ph. Eur., BP, USP, FC, E 337
impurities   acidity or alkalinity, in accordance
  residual solvent, complies
  ≤0.001% heavy metals (as Pb)
  ≤0.003% total nitrogen (N)
  ≤0.004% ammonium (NH4)
  ≤0.004% free alkali (as NaOH)
  ≤0.0075% free acid (as C4H6O6)
  24-26% water (Karl Fischer)
loss   21-26% loss on drying, 150 °C, 3 h
pH   6.5-8.5 (20 °C, 1%)
anion traces   chloride (Cl-): ≤20 mg/kg
  sulfate (SO42-): ≤50 mg/kg
cation traces   As: ≤1 mg/kg
  Ba:, in accordance
  Ca: ≤50 mg/kg
  Cu: ≤10 mg/kg
  Fe: ≤10 mg/kg
  Hg: ≤1 mg/kg
  Pb: ≤2 mg/kg
  Zn: ≤10 mg/kg
suitability   passes test for appearance of solution



Potassium sodium tartrate tetrahydrate has been used in the β-1,3-glucanase activity assay.

General description

Potassium sodium tartrate tetrahydrate (Rochelle salt) exists in the ferroelectric phase in the temperature range of 255 to 297K. In this phase, it crystallizes in the monoclinic system and exhibits space group P21. Saturated aqueous solution of potassium sodium tartrate (Rochelle salt) has been used for the preparation of its tetrahydrate crystals.

Price and Availability

Suggested Laboratory Gloves

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Safety & Documentation

Safety Information

NONH for all modes of transport
WGK Germany 
Protocols & Articles
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