无水柠檬酸是什么?它是一种化学成分,由杂质组成,都有那些成分?

柠檬酸钠是一种防腐剂吗?有人说一水柠檬酸和无水柠檬酸就是柠檬酸钠对吗?
在食品添加剂使用中,起的作用有什么不同?

寻求(阿斯巴甜/苯甲酸钠 /无水柠檬酸/甜蜜素/磷酸 85%/糖精钠/山梨酸钾）厂商供应
寻求厂商供应,产品规定如下
阿斯巴甜
cas no :22839-47-0
heavy metals (ppm = mg/kg) :< 10 ppm
mesh :80% @ 100 mesh
ph :5
content :99.85%
l-alpha-as***l-l-phenylalanine :< 0.25%
苯甲酸钠
cas-no :532-32-1
appearance :white granular
moisture :< 1.5%
heavy metals (ppm = mg/kg) :< 10 ppm
ph :8 (1% solution)
total cl content :< 300 ppm
content :99.0 - 100.5% (as dry product c7h5)
无水柠檬酸
cas-no :77-92-9
appearance :white crystals
moisture :< 0.5%
heavy metals (ppm = mg/kg) :< 5 ppm
mesh :30 - 100
content :99.5 - 100.5%
甜蜜素
cas no :139-05-9
appearance :white crystals
moisture :< 1%
heavy metals (ppm = mg/kg) :< 10 ppm
mesh :40 - 80
ph :5.5 - 7.5 (100g/l)
content :98.5 - 101.0%
磷酸 85%
cas no :7664-38-2
appearance :clear and viscous liquid
sulfate (so4) :< 900 ppm
heavy metals (ppm = mg/kg) :< 10 ppm
total cl content :< 20 ppm
content :85%
h3po4 :85%
p2o5 :61.6%
density 25°c/25°c :1,685
color apha :< 15
糖精钠
cas no :6155-57-3
appearance :white crystals
moisture :≤ 1.0%
heavy metals (ppm = mg/kg) :6.2 ppm
mesh :20 - 40
ph :7
content :99.0 - 101.0%
ammonium salts :13 ppm
山梨酸钾
cas no :24634-61-5
appearance :white granular
moisture :< 1%
heavy metals (ppm = mg/kg) :≤ 2 ppm
mesh :50
content :98.0 - 101.0%