质量标准
99%:
外观Appearance White Crystalline Powder
纯度Purity by Titration by NaOH ≥99.0 %
水溶性Solubility Colorless Clear ,5 g plus 95 ml of H2O
红外光谱Infrared spectrum Conforms to Structure
干燥失重Loss on Drying ≤1.0 %
A290 UV absorbance ≤0.02
(c = 5% w/w)
重金属Heavy Metals (As Lead) ≤5 ppm
Ultra pure,≥99.5% (T):
外观Appearance White Crystalline Powder
纯度Purity ≥99.5% (T)
不溶物insoluble matter, passes filter test
灼烧残渣Residue on ignition (900 °C) ≤0.05%
干燥损失loss on drying, 20 °C (HV) ≤0.5%
pH 3.0-4.5 (25 °C, 0.1 M in H2O)
useful pH range 6.1 - 7.5
pKa (25 °C) 6.8
水溶性solubility H2O: soluble0.1 M at 20 °C, clear, colorless
氯chloride (Cl-): ≤250 ppm
硫酸根sulfate (SO42-): ≤50 ppm
Al: ≤10 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: ≤50 ppm
Ni: ≤5 ppm
Pb: ≤5 ppm
Sr: ≤5 ppm
Zn: ≤5 ppm
λ 0.1 M in H2O
UV absorption λ: 260 nm A: ≤0.008
λ: 280 nm A: ≤0.005