POTASSIUM GLUCONATE-葡糖酸钾

POTASSIUM GLUCONATE Prepared at the 51st JECFA (1998), published in FNP 52 Add 6 (1998) superseding specifications prepared at the 23rd JECFA (1979), published in FNP 12 (1979). Group ADI "not specified" for glucono-delta-lactone and gluconates, excluding ferrous gluconate, established at the 51st JECFA in 1998. SYNONYMS Potassium D-gluconate; INS No. 577 DEFINITION Chemical names Potassium D-gluconate C.A.S. number 299-27-4 (Anhydrous) 35398-15-3 (Monohydrate) Chemical formula C6H11KO7 Structural formula Formula weight 234.25 (Anhydrous) 252.26 (Monohydrate) Assay Not less than 97.0% and not more than 103.0% on dried basis DESCRIPTION Odourless, free flowing white to yellowish white, crystalline powder or granules FUNCTIONAL USES Acidity regulator, nutrient supplement, yeast food CHARACTERISTICS IDENTIFICATION Test for potassium (Vol. 4) Passes test Test for gluconate (Vol. 4) Passes test PURITY Loss on drying (Vol. 4) Anhydrous: Not more than 3% (105o, 4 h, under vacuum) Monohydrate: Not less than 6% and not more than 7.5% (105o, 4 h, under vacuum) Reducing substances (Vol. 4) Not more than 1.0% calculated as D-glucose (Method I) Lead (Vol. 4) Not more than 2 mg/kg Determine using an atomic absorption technique appropriate to the specified level. The selection of sample size and method of sample preparation may be based on the principles of the method described in Volume 4, “Instrumental Methods.” METHOD OF ASSAY Transfer about 175 mg of the sample, accurately weighed, into a clean, dry 200-ml Erlenmeyer flask, add 75 ml of glacial acetic acid and dissolve by heating on a hot plate. Cool, add quinaldine red TS, and titrate with 0.1 N perchloric acid in glacial acetic acid, using a 10-ml microburet, to a colourless end point. Each ml of 0.1 N perchloric acid is equivalent to 23.42 mg of C6H11KO7. POTASSIUM GLUCONATE SYNONYMS DEFINITION Chemical names C.A.S. number Chemical formula Structural formula Formula weight Assay DESCRIPTION FUNCTIONAL USES CHARACTERISTICS IDENTIFICATION PURITY METHOD OF ASSAY