色泽和组织状态

Appearance   description

无色针状结晶性粉末(无水)
  无色结晶性颗粒(三水)

White   crystalline odorless powder ,anhydrous
   

White   crystalline odorless granular, trihydrate

含量，%

Assay(C₂H₃NaO₂,on   dried basis)%

≥

99.0-101

99.0-101

≥98.5

PH值(1%水溶液)

PH   (1%aqueous  solution)

8.0-9.5

游离碱

Alkalinity %

≤

Pass

0.2  ,anhydrous
  0.05 ,trihydrate

钾实验

Potassium Compounds%  

≤

Pass

Pass test

干燥失重

Loss on drying
  %

≤

2.0,无水
   
  36.0-42.0,三水

1.0        anhydrous
   
  36.0-41.0 trihydrate

2.0(Anhydrous   120℃,4hours)
  
  36.0-42.0(Trihydrate ,120℃,4hours)

甲酸及其他易氧化物实验

Formic acid,
  formats and other oxidisable substances %

≤

0.1

铅%

Lead(Pb)%

≤

0.0002

0.0002

0.0002

砷盐（以As计），%

Arsenic (As)%

≤

0.0003

汞%

Mercury (Hg)
  %

≤

0.0001