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Propylene Glycol Alginate
» Propylene Glycol Alginate is a propylene glycol ester of alginic acid. Each g yields not less than 0.16 and not more than 0.20 g of carbon dioxide, calculated on the dried basis.
Packaging and storage
Preserve in well-closed containers.
Identification
Place 20 mL of the saponified solution obtained in the determination of Esterified carboxyl groups in a 250-mL conical flask, add 50 mL of a solution of periodic acid (1 in 50), swirl, and allow to stand for 30 minutes. Add 2 g of potassium iodide, titrate with sodium thiosulfate TS to a faint yellow color, dilute the mixture with water to 200 mL, and mix to obtain the test solution for tests A and B.
A:
Dissolve 200 mg of rosaniline hydrochloride, C20H20ClN3, in 120 mL of hot water. Cool, add 2 g of sodium bisulfite, NaHSO3, followed by 2 mL of hydrochloric acid, and dilute with water to 200 mL to obtain modified Schiff's reagent. (Store this solution in a brown bottle at 15
B:
To 10 mL of the test solution add 1 mL of a saturated solution of piperazine and 0.5 mL of sodium nitroferricyanide TS: a green color, due to acetaldehyde, develops.
Microbial enumeration tests
Loss on drying
Ash
Weigh accurately about 3 g in a tared crucible, and incinerate at 650 ± 25
Arsenic, Method II
Lead
Heavy metals, Method II
Free carboxyl groups
Transfer about 1 g, accurately weighed, to a 600-mL beaker. Dissolve in 200 mL of water, stirring by mechanical means for not less than 30 minutes, and titrate with 0.1 N sodium hydroxide VS to a pH of 7.0, determining the endpoint potentiometrically. Calculate the weight, in g, of free carboxyl groups in the weight, W, in g, of specimen taken by the formula:
0.0044V / W
in which V is the volume, in mL, of 0.1 N sodium hydroxide consumed: the weight of free carboxyl groups found, calculated on the dried basis, is not more than 35% of the weight of carbon dioxide yielded by an equal weight of specimen in the Assay.
Esterified carboxyl groups
Transfer the solution obtained in the test for Free carboxyl groups with the aid of water to a 1000-mL conical flask, add phenolphthalein TS and 50.0 mL of 0.1 N sodium hydroxide VS, insert a stopper in the flask, mix, and allow to stand for 30 minutes at ambient temperature. Titrate the excess sodium hydroxide with 0.1 N hydrochloric acid VS to a faint pink endpoint. Transfer the solution with the aid of water to a 600-mL beaker, and complete the titration to a pH of 7.0, determining the endpoint potentiometrically. Calculate the weight, in g, of esterified carboxyl groups in the weight, W, in g, of specimen taken by the formula:
0.0044v / W
in which v is the volume, in mL, of 0.1 N sodium hydroxide consumed: the weight of esterified carboxyl groups found, calculated on the dried basis, is between 40% and 85% of the weight of carbon dioxide yielded by an equal weight of specimen in the Assay.
Assay
Proceed as directed for Procedure under Alginates Assay
Auxiliary Information
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Chromatographic Column
USP32NF27 Page 1325
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
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