BS ISO 20634 pdf free download

BS ISO 20634 2015 pdf free download.Infant formula and adult nutritionals — Determination of vitamin B 12 by reversed phase high performance liquid chromatography (RP-HPLC).
This International Standard specifies a method for the quantitative determination of vitamin B 12 in infant and adult formula (powders, ready-to-feed liquids and liquid concentrates) by reversed phase high performance liquid chromatography.
2 Terms and definitions For the purposes of this document, the following terms and definitions apply.
2.1 vitamin B 12 cyanocobalamin and other cobalt-containing corrinoids with vitamin B 12 biological activity, such as aquocobalamin, hydroxycobalamin, methylcobalamin and adenosylcobalamin, converted to cyanocobalamin
2.2 adult nutritional nutritionally complete, specially formulated food, consumed in liquid form, which may constitute the sole source of nourishment, made from any combination of milk, soy, rice, whey, hydrolysed protein, starch and amino acids, with and without intact protein
2.3 infant formula breast-milk substitute specially manufactured to satisfy, by itself, the nutritional requirements of infants during the first months of life up to the introduction of appropriate complementary feeding [SOURCE: Codex Standard 72-1981] 3 Principle Cyanocobalamin and other cobalt-containing corrinoids are extracted from the sample using sodium acetate buffer (pH = 4,5) and the latter converted to cyanocobalamin using potassium cyanide at 105 °C. Extracts are purified and concentrated with C8 or C18 solid-phase extraction (SPE) cartridges and analysed with size-exclusion and reversed-phase chromatography. Determination of vitamin B 12 is made by liquid chromatography with visible detection at 550 nm. 4 Reagents and materials During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and distilled or demineralized water or water of equivalent purity.
4.1 Glacial acetic acid.
4.2 Acetonitrile, HPLC grade.
4.3 Drierite, desiccant, anhydrous calcium sulfate, 8 mesh.
4.4 Ethanol, denatured.
4.5 Formic acid, 88 %.
4.6 Potassium cyanide, 97 %.
4.7? Riboflavin, 98 % to 102 % purity.
4.8 Sodium acetate anhydrous or sodium acetate trihydrate, ACS.
4.9 Taka-Diastase, Accurate Chemical Co. 1) or equivalent.
4.10 Triethylamine, HPLC grade.
4.11 Vitamin B 12 (cyanocobalamin) primary reference standard, e.g. USP Reference 1152009 (approximately 10 µg/mg), Official lot 1) . Store in a desiccator protected from white light.
4.12 Preparation of solutions and standard solutions
4.12.1 General
All solutions may be scaled up or down for convenience provided good laboratory practices are observed. Solutions can be stored refrigerated or at ambient temperature in tight, inert containers unless otherwise specified.
4.12.2 Preparation of solutions
4.12.2.1 HPLC mobile phase A. Dilute 4,0 ml of triethylamine with 1 000 ml of water. Adjust the pH to 5 to 7 with approximately 1,25 ml concentrated formic acid (4.5). Expiration: 1 week.
4.12.2.2 HPLC mobile phase B. Mix 4,0 ml of triethylamine and 250 ml of acetonitrile with 750 ml of water. Adjust the pH to 5 to 7 with approximately 1,25 ml concentrated formic acid. Expiration: 1 week in tightly stoppered container.
4.12.2.3 HPLC mobile phase C. Mix 4,0 ml of triethylamine and 750 ml of acetonitrile with 250 ml of water. Adjust the pH to 5 to 7 with approximately 1,25 ml concentrated formic acid. Expiration: 1 week in tightly stoppered container.
4.12.2.4 HPLC mobile phase D. Dilute 50 ml of acetonitrile to 2 000 ml with water. Expiration: 1 week in tightly stoppered container.
4.12.2.5 Mixture of acetonitrile and water, volume fraction 10 %. Dilute 150 ml of acetonitrile to 1 500 ml with water. Expiration: 1 month in tightly stoppered container.
4.12.2.6 Mixture of acetonitrile and water, SPE elution solvent, volume fraction 30 %. Dilute 30 ml of acetonitrile to 100 ml with water. Expiration: 1 month in tightly stoppered container.
4.12.2.7 Mixture of acetonitrile and water, column cleaning and storage solution, volume fraction 50 %. Dilute 500 ml of acetonitrile to 1 000 ml with water in a volumetric flask. Expiration: 6 months.
4.12.2.8 Mixture of ethanol and water, volume fraction 25 %. Dilute 50 ml of ethanol to 200 ml with water. Expiration: 1 year in tightly stoppered container.
4.12.2.9 Potassium cyanide solution, mass concentration ρ = 4 g/l. Dissolve 0,02 g of potassium cyanide in and dilute to 5 ml with sodium acetate buffer (4.12.2.11) substance concentration c = 0,25 mol/l). Prepare fresh immediately before use.
4.12.2.10 Potassium cyanide solution, ρ = 10 g/l. Dissolve 0,25 g of potassium cyanide in water and dilute to 25 ml. Prepare fresh immediately before use.BS ISO 20634 pdf download.