FCCV标准-Sodium Bisulfite亚硫酸氢钠.pdf

406/Sodium Bisulfate/ Monographs
FCCV
Sodium Bisulfate
Sodium Bisulfite
Sodium Acid Sulfate; Nitre Cake
Sodium Acid Sulfite; Sodium Hydrogen Sulfite
NaHSO4
Formula wt 120.06 NaHSO3
Formula wt 104.06
INS: 514
cas:7681-38-1ins:222
cAS:17631-90-5
DESCRIPTION
DESCRIPTION
Sodium Bisulfate occurs as white crystals or granules. It is Sodium Bisulfite occurs as white or yellow-white crystals o
s or
soluble in water, and its solutions are strongly acid. It is as a granular powder It consists of sodium bisulfite (NaHSO3)
decomposed by alcohol into sodium sulfate and free sulfu-
a
ric acid.
and sodium metabisulfite (Na2S205) in varying proportions
and, for all practical purposes, possesses properties of the true
Function Acidifier.
bisulfite. It is unstable in air. One gram dissolves in 4 mL of
water. It is slightly soluble in alcohol.
REQUIREMENTS
Function Preservative.
Identification A sample gives positive tests for Sodium and
for Sulfate, Appendix IIIA
REQUIREMENTS
Assay Not less than 35.0% and not more than 39.0% of
available H2SO4, equivalent to not less than 85.4% and not Identification A 1: 10 aqueous solution gives positive tests
more than 95.2% of NaHSO4.
for Sodium and for Sulfite, Appendix IIIA.
Lead Not more than 2 mg/kg.
Assay Not less than 58.5% and not more than 67.4% of SO2
2
Loss on Drying Not more than 0.8%.
Iron Not more than 0.005%.
Selenium Not more than 5 mg/kg.
Lead Not more than 2 mg/kg.
Water-Insoluble Substances Not more than 0.05%.
.
Selenium Not more than 5 mg/kg
TESTS
TESTS
Assay Dissolve about 5 g of sample, accurately weighed, Assay Add about 200 mg of sample, accurately weighed,
in about 125 mL of water, add phenolphthalein TS and titrate to 50.0 mL of 0. N iodine contained in a glass-stoppered
with 1 N sodium hydroxide. Each milliliter of 1 N sodium
hydroxide is equivalent to 49.04 mg of H2SO4, or to 120.06 5 min, add mL of hydrochloric acid, and titrate the excess
is equivalent to 3.203
under Lead Limit Test, Appendix II
mg of SO2
- Iron Add 2 mL of hydroch
500 mg of sample,
ing, Appendix IC, drying a sample in a desiccator over phos- and evaporate to dryness on a steam bath. Dissolve the residue
phorus pentoxide for 24 h.
in mL of hydrochloric acid and 20 mL of water, add a few
Selenium
irected in Method under Sele- drops of bromine TS, and boil the solution to remove the
nium Limit Test, Appendix, using a 1.2-g sample
bromine. Cool, dilute with wa
25 mL, then add 50 mg
Water-Insoluble Substances Dissolve 50 g of sample in of ammonium p
ammonium thiocyanate
300 mL of hot water co
ned in a 600-mL beaker, allow
TS. Any red
produ
iced i
n
the insoluble matter to settle; and filter by decanting through a control containing 2.
ard Solution (25
a tared, sintered-glass filter crucible, washing the insoluble ug Fe)(see
matter into the crucible with additional hot water. Dry at 100
ction Method
to 110 for 1 h, cool in a desiccator, and weigh.
under Lead Limit
Selenium Determine as dir
under the Sele-
Packaging and Storage Store in tight containers
ni