Sodium phosphate dibasic

Agency

meets analytical specifications of BP
meets analytical specifications of Ph. Eur.
meets analytical specifications of USP

Quality Level

200

grade

puriss.

Assay

98-100.5% (calc. to the dried substance)

form

powder

quality

meets analytical specification of Ph. Eur., BP, USP, FCC, E 339

impurities

reducing matter, complies
residual solvents, complies
≤0.001% heavy metals (as Pb)
≤0.002% ammonium (NH₄)
≤0.2% water-insoluble matter
≤1% NaH₂PO₄ (calc. to dried subst.)
≤2.0% pyrophosphate (as Na₄P₂O₇)

loss

≤1% loss on drying, 105°C, 4h
≤1% loss on drying, 130 °C

pH

8.4-9.6 (20 °C, 1%)

pKa (25 °C)

(1) 2.15, (2) 6.82, (3) 12.38 (phosphoric acid)

solubility

H₂O: soluble 8 parts
H₂O: very soluble (Hot)
alcohol: insoluble

anion traces

chloride (Cl^-): ≤50 mg/kg
fluoride (F^-): ≤10 mg/kg
sulfate (SO₄^2-): ≤200 mg/kg

cation traces

As: ≤2 mg/kg
Cd: ≤1 mg/kg
Cu: ≤10 mg/kg
Fe: ≤20 mg/kg
Hg: ≤1 mg/kg
Pb: ≤4 mg/kg
Zn: ≤10 mg/kg

suitability

complies for appearance of solution

SMILES string

[Na+].[Na+].[H]OP([O-])([O-])=O

InChI

1S/2Na.H3O4P/c;;1-5(2,3)4/h;;(H3,1,2,3,4)/q2*+1;/p-2

InChI key

BNIILDVGGAEEIG-UHFFFAOYSA-L