质量标准
98%:
外观appearance white crystalline powder
可溶性solubility clear colorless,160mg/ml in 1N sodium hydroxide
红外光谱Infrared spectrometry Conforms to Structure
干燥损失loss on drying ≤1%
重金属heavy metals(as lead) ≤5ppm
纯度Purity(Neutralization titration) ≥98%
Ultra Pure, ≥99.0% (T)
外观appearance white crystalline powder
纯度Purity(Neutralization titration) ≥99%
不溶物insoluble matter, passes filter test
灼烧残渣ign. residue ≤0.1%
干燥损失loss on drying, 20 °C (HV) ≤0.5%
pH 1.5-3.0 (25 °C, 0.01 M in H2O)
useful pH range 6.0 - 7.2
pKa (25 °C) 6.6
水溶性solubility H2O: soluble0.05 M, clear, colorless
氯chloride (Cl-): ≤1000 ppm
硫酸根sulfate (SO42-): ≤50 ppm
Al: ≤5 ppm
As: ≤0.1 ppm
Ba: ≤5 ppm
Bi: ≤5 ppm
Ca: ≤10 ppm
Cd: ≤5 ppm
Co: ≤5 ppm
Cr: ≤5 ppm
Cu: ≤5 ppm
Fe: ≤5 ppm
K: ≤50 ppm
Li: ≤5 ppm
Mg: ≤5 ppm
Mn: ≤5 ppm
Mo: ≤5 ppm
Na: ≤500 ppm
Ni: ≤5 ppm
Pb: ≤5 ppm
Sr: ≤5 ppm
Zn: ≤5 ppm
λ 0.05 M in H2O
UV absorption λ: 260 nm A: ≤0.20
λ: 280 nm A: ≤0.05