Cupric Tartrate TS, Alkaline

Standardized Fehling s Solution Measure a quantity of Fehling s Solution A, add an equal quantity of Fehling s Solution B, and mix (see Cupric Tartrate TS, Alkaline in the... 

Alkaline Cupric Tartrate TS (Fehling s Solution) See Cupric Tartrate TS, Alkaline. 

A. A 1 50 aqueous solution slowly reduces alkaline cupric tartrate TS at 25°, but more readily upon heating. 

A. Add 5 mL of sulfuric acid TS to 10 mL of a 2% aqueous suspension of sample, heat in a boiling water bath for 30 min, and cool. Neutralize the mixture with barium carbonate, and centrifuge it at 900 g for 10 min. Add 1 mL of the supernatant to 5 mL of hot alkaline cupric tartrate TS. A copious red precipitate of cuprous oxide forms. 

Identification Add a few drops of a 1 20 aqueous solution to 5 mL of hot alkaline cupric tartrate TS. A copious red precipitate of cuprous oxide forms. 

Reducing Sugars Dissolve 500 mg of sample in 10 mL of water, warm, and make the solution alkaline with 1 mL of 6 N ammonium hydroxide. Pass hydrogen sulfide gas into the solution to precipitate the iron, and allow the mixture to stand for 30 min to coagulate the precipitate. Filter, and wash the precipitate with two successive 5-mL portions of water. Acidify the combined filtrate and washings with hydrochloric acid, and add 2 mL of 2.7 N hydrochloric acid in excess. Boil the solution until the vapors no longer darken lead acetate paper, and continue to boil, if necessary, until the solution has been concentrated to about 10 mL. Cool, add 5 mL of sodium carbonate TS and 20 mL of water, filter, and adjust the volume of the filtrate to 100 mL with water. Add 2 mL of alkaline cupric tartrate TS to 5 mL of filtrate, and boil for 1 min. No red precipitate forms within 1 min. 

Identification Add 5 mL of 1 N sodium hydroxide to 5 mL of a hot, saturated solution of sample, and gently warm the mixture. The liquid turns yellow and, finally, brown-red. Cool to room temperature, and add a few drops of alkaline cupric tartrate TS. A red precipitate of cuprous oxide forms. 

Algin, 24, 54,312, 351 Alginates Assay, 768 Algin Derivative, 331 AlginicAcid, 19 Alkaline Borate Buffer, 848 Alkaline Cupric Citrate TS, 851 Alkaline Cupric Tartrate TS, 849 Alkaline Mercuric-Potassium Iodide TS, 850... 

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