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GB 5413.31-2013 PDF in English


GB 5413.31-2013 (GB5413.31-2013) PDF English
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GB 5413.31-2013English70 Add to Cart 0-9 seconds. Auto-delivery. National Food Safety Standard Determination of urease in infant foods and dairy products Valid
GB/T 5413.31-1997English199 Add to Cart 2 days Milk powder and formula foods for infant and young children--Qualitative detection of urease Obsolete
Standards related to (historical): GB 5413.31-2013
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GB 5413.31-2013: PDF in English

GB/T 5413.31-2013 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA National standard on food safety Infant food and dairy products – Determination of urease ISSUED ON. NOVEMBER 29, 2013 IMPLEMENTED ON. JUNE 01, 2014 Issued by. National Family Planning Commission Table of contents Foreword ... 3  1 Scope ... 4  2 Principles ... 4  3 Reagents and materials ... 4  4 Instruments and equipment ... 6  5 Analysis steps ... 6  6 Presentation of analysis results ... 6  7 Detection limit ... 7  Foreword This standard replaces GB/T 5413.31-1997 Milk powder and formula foods for infant and young children - Qualitative detection of urease. As compared with GB/T 5413.31-1997, the main changes of this standard are as follows. - MODIFY the standard name; - ADD the storage conditions for urea solution; - ADD the storage conditions for Nessler's reagent; - ADD the time limit for determination results. National standard on food safety Food and dairy products for infant and young children - Determination of urease 1 Scope This standard specifies the determination methods for urease in infant foods and dairy products. This standard applies to qualitative detection of urease in infant food and dairy urease. 2 Principles Under the appropriate pH and temperature conditions, urease will catalyze the urea to convert into ammonium carbonate. Ammonium carbonate will, under the alkaline conditions, generate ammonium hydroxide, which will react with the potassium iodide double salt in the Nessler's reagent to produce brown double- mercury ammonium iodide. 3 Reagents and materials Note. Unless otherwise stated, the reagents used in this standard are of analytical pure AND the water is grade III water as specified in GB/T 6682. 3.1 Reagents 3.1.1 Urea (H2NCONH2). 3.1.2 Sodium tungstate (Na2WO4•2H2O). 3.1.3 Potassium sodium tartrate (C4H4O6KNa•4H2O). 3.1.4 Sulfuric acid (H2SO4). 3.1.5 Disodium hydrogen phosphate (Na2HPO4). 3.1.6 Potassium dihydrogen phosphate (KH2PO4). ......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.