FCCV标准-Sodium Tripolyphosphate三聚磷酸钠.pdf

IECC V
Monographs / Sodium Tripolyphosphate/ 439
Assay Nol less than 99. 0% and not more than 100.5% of ML of nitric acid, cover with a watch glass, and boil for 10
Na2s203 after drying
min on a hot plate. Rinse any condensate from the watch
Lead Not more than 2 m/kg
glass into the beaker, cool the solution to room temperature
Selenium Not more than 0.0030
fer it quantitatively to a 500-ML volumetric flask, dilute
Water Between 32.0% and 370
to volume with water, and mix thoroughly Pipet 20.0 ML o
this solution Into a 500-ML Erlenmeyer flask, add 100 ML
TESTS
of water, and heat just to boiling. While stirring, add 50 ml
of quimociac TS, then cover with a watch glass, and boil for
Assay Accurately weigh about 500 mg of the dried sample I min in a well-ventilated hood. Cool to room temperature
obtained in the test for Waler(below), dissolve il in 30 ML
swirling occasionally while cooling, then filter through a tared,
of water, and titrate wih 0. 1 N odine, using starch TS as the sintered-glass filter crucible of medium porosity, and wash
indicator. Each milliliter of 0.1 N iodine is equivalent to 15.8
the precipitate with live 25-ML portions of water. Dry the
mg of Na2s2o3
precipitate at about 225 for 30 min, cool, and weigh. Each
ead Determine as directed in the A Pdchctraction Method
milligram of precipitate thus obtained is equivalent to 32.074
under head imil fes/, Appendix IIIB
ug of P2O5
Selenium Determine as directed in Method I under Selenium Arsenic Determine as directed under Arenic mit est
Limit Test, Appendix IIIB, using a 200-mg sample
Appendix IIIB, using a solulion of 1 g of sample in 35 ml
Water Dry about I g of sample, accurately weighed, in a of water
vacuum at40°1o45°for16h,cool, and weigh
Fluoride Determine as directed in Method I under Fuo
ride Limit Ies/, Appendix IIB, using a 2-g sample
Packaging and Storage Store in tight containers
Insoluble Substances Dissolve 10 g of sample in
of hot water, and filter the solution through a tared filtering
crucible. Wash the insoluble residue with hot water, dry al
105°for2h.
and weigh
Sodium Trimetaphosphate
Lead Determine as directed in the APD(Exraction Method
under Lead Limit Test, A
ppendix IIB
(Napo)
Formula wt 305. 89
CAS:17785-84-4
Packaging and Storage Store in tight containers
DESCRIPTION
Sodium Trimetaphosphate occurs as white crystals or as a Sodium T'ripolyp hosphate
white, crystalline powder. It is a cyclic polyphosphate com
posed of three metaphosphate units. It is freely soluble in Pentasodium Triphosphate; Triphosphate; Sodium
water. The ph of a 1: 100 aqueous solution is about 6.0
Triphosphate
Function Starch-modifying agent
Nasp3 O10
Formula wt, anhydrous 367.86
Nasp2o10 6H,O
Formula wl, hexahydrate 475.96
REQUIREMENTS
INS:451(1)
CAS: anhydrous [7758-29-41
CAS: hexahydrate [15091-98-2
Identification
A 1: 20 aqueous solution gives positive tests for Sodium
Appendix IIIA
B. Dissolve about 100 mg of sample in 5 ml of hot 1.7 DESCRIPTION
N nitric acid, warm on a steam bath for 10 min, and cool
Sodium Tripolyphosphate occurs as white, slightly hy ro-
Neutralize to litmus paper with I N sodium hydroxide, and scopic granules, o