FCCV标准-Stannous Chloride氯化锡.pdf

IECC V
Monographs Starter Distillate/ 449
Packaging and Storage Store in a cool place protected the steam bath. Dissolve the residue in a few milliliters of
from light in full, tight containers that are made from steel water and 8 ML of hydrochloric acid, dilute to 100 ML with
or aluminum and that are suitably lined
water, and mix. Add 2 ML of hydrochloric acid, 46 ml of
water, 40 mg of ammonium persulfate crystals, and 3 m
ammonium thiocyanate TS to 2.0 ml of this solution. Any
red or pink color does nol exceed that produced by 2.0 ML
of Iron Standard Solution (20 ug of Fe)in an equal volume
Stannous Chloride
of solution containing the quantities of the reagents used in
Tin Dichloride
Lead Determine as directed in the APDC Extraction Method
Snci
Formula wt, anhydrous 189.60
under Lead Limit est, Appendix IIIB, using a 5-g sample
SNCL22H2O
Formula wt. dihydrate 225.63
Solubility in Hydrochloric Acid Dissolve a 5-g sample in
a mixture of 5 ML of hydrochloric acid and 5 ML of water
IINS: 521
CAS: anhydrous [7772-99-8] heating t0 40, if necessary, to effect solulion. The sample
CAS: dihydrate [10025-0960-0911 dissolves completely, and the solution Is clear
Substances Not Precipitated by Sulfide Transfer about 20
g o! sample, accurately weighed, into a 250-ML
DESCRIPTON
add 50 ML of a solution prepared by carefully adding 75 ML
of bromine to 425 ml of 48% hydrobromic acid. Add 1 ML
Stannous Chloride occurs as white or colorless crystals. It is o! sulfuric acid, and mix to eflect complete solution. Place
anhydrous or contains two molecules of water of hydration. the beaker on a hot plate, and volatilize the tin slowly, with
It is very soluble in water, and it is soluble in alcohol and in gentle boiling, to fumes of sulfur trioxide. Cool, add 30 ML
glacial acetic acid.
o! water, and pass hydrogen sulfide gas through the solulion
for about 5 min Filter through Whatman No 42 filter paper
Function Reducing agent: antioxidan
or equivalent, into a weighed platinum dish, and wash with
three small portions of a I% solution of sulfuric acid saturated
REQUIREMENTS
with hydrogen sulfide. Carefully evaporate to dryness on a
hot plate, and heat in a furnace al800°±25°for13min.
ldentification
Cool in a desiccator for at least 30 min and weigh. Calculate
A. Add mercuric chloride TS, dropwise, to a 1: 20 solution the percentage of substances not precipitated by sulfide by
of sample in 2.7 N hydrochloric acid. A white or gray-white the formula
precipitate forms
B A 1: 20 aqueous solution gives positive tests for Chloride
100A/B,
Appendix IIIA
in which d and B are the respective weights, in grams, o! the
Assay Not less than 99.0% and not more than 10].0% of residue and of the sample taken. Retain the residue for the
Sncl>, or nol less than 98.0% and not more than 102.2 of Iron test(above
ncl>O
Sulfate Dissolve 5 g of sample in 5 ML of hydrochloric
Iron Not more than 0.005%
acid. dilute to 50 ml with water. filter if not clear. and heat
Lead Not more than 4 mg/kg
the filtrate or clear solution to boiling. Add 5 ML of barium
Solubility in Hydrochloric Acid Passes test
chloride TS. digest in a covered beaker on a steam bath for
Substances Not Precipitated by Sulfide