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GB 5009.168-2016 PDF in English


GB 5009.168-2016 (GB5009.168-2016) PDF English
Standard IDContents [version]USDSTEP2[PDF] delivered inName of Chinese StandardStatus
GB 5009.168-2016English125 Add to Cart 0-9 seconds. Auto-delivery. National food safety standard -- determination of fatty acid in foods Valid
GB/T 5009.168-2003English239 Add to Cart 3 days Determination of eicosapentaenoic acid and docosahexaenoic acid in foods Obsolete
Standards related to (historical): GB 5009.168-2016
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GB 5009.168-2016: PDF in English

GB 5009.168-2016 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA National food safety standard Determination of fatty acids in foods ISSUED ON. DECEMBER 23, 2016 IMPLEMENTED ON. JUNE 23, 2017 Issued by. National Health and Family Planning Commission of the People’s Republic of China; China Food and Drug Administration. 3. No action is required - Full-copy of this standard will be automatically & immediately delivered to your EMAIL address in 0~60 minutes. Table of Contents Foreword ... 4 1 Scope ... 5 2 Principle ... 5 3 Reagents and materials ... 6 4 Apparatus and equipment ... 7 5 Analysis procedure ... 8 6 Expression of analysis results ... 11 7 Principle ... 14 8 Reagents and materials ... 15 9 Apparatus and equipment ... 17 10 Analysis procedure ... 17 11 Expression of analysis results ... 19 12 Principle ... 20 13 Reagents and materials ... 20 14 Apparatus and equipment ... 20 15 Analysis procedure ... 21 16 Expression of analysis results ... 21 17 Precision ... 22 18 Quantitation limits ... 22 Annex A Molecular formula and CAS number of single fatty acid methyl ester standards ... 23 Annex B Typical reference chromatogram of 37 kinds of fatty acid methyl ester standard solutions ... 25 Annex C Retention time and relative retention time reference for fatty acid methyl esters ... 26 Annex D Coefficients for conversion between fatty acid methyl esters, fatty acids and fatty acid triglycerides ... 28 Annex E Quantitation limits for fatty acids ... 30 Foreword This Standard replaces GB/T 5009.168-2003 “Determination of eicosapentaenoic acid and docosahexaenoic acid in foods”, GB/T 22223-2008 “Determination of total fat, saturated fat, and unsaturated fat in foods - Hydrolytic Extraction - Gas Chromatography”, GB 5413.27-2010 “National food safety standard - Determination of fatty acids in foods for infants and young children milk and milk products”, GB/T 9695.2-2008 “Meat and meat products - Determination of fatty acids”, GB/T 17376- 2008 “Animal and vegetable fats and oils - Preparation of methyl esters of fatty acids”, GB/T 17377-2008 “Animal and vegetable fats and oils - Analysis by gas chromatography of methyl esters of fatty acids”, SN/T 2922-2011 “Determination of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in foods for export - Gas chromatography”, NY/T 91-1988 “Determination of erucic acid in the oil of rapeseed - Gas chromatographic method”. Compared with GB/T 5009.168-2003, the main changes of this Standard are as follows. - the standard name is changed to “National food safety standard - Determination of fatty acids in foods”; - ADD the internal standard method and the normalization method; - MODIFY the chromatographic column in the original standard, changing the glass column to capillary chromatographic column. National food safety standard Determination of fatty acids in foods 1 Scope This Standard specifies the determination method for the content of fatty acids in foods. This Standard applies to the determination of total fats, saturated fats (fatty acids) and unsaturated fats (fatty acids) in foods. In this Standard, the hydrolysis-extraction method applies to the determination of the content of fatty acids in foods; the transesterification method applies to the determination of the content of fatty acids in fat samples with free fatty acid content of not more than 2 %; the acetyl chloride-methanol method applies to the determination of the content of fatty acids in milk powder and anhydrous cream samples with water content less than 5 %. Method I Internal standard method 2 Principle 2.1 Hydrolysis-extraction method. after the fats in the sample that has added with internal standard are extracted with hydrolysis-ether solution, saponify and methyl- esterify the sample under alkaline conditions to produce fatty acid methyl esters. After analyzed by capillary column gas chromatography, use internal standard method to quantitatively determine the content of fatty acid methyl esters. According to the content and conversion coefficients of various fatty acid methyl esters, calculate the content of total fats, saturated fats (fatty acids), monounsaturated fats (fatty acids) and polyunsaturated fats (fatty acids). Animal and vegetable fat samples are directly saponified and fatty-acid-methyl esterified after adding with internal standard, without fat extraction. 2.2 Transesterification method (applies to fats with free fatty acid content of not more than 2 %). DISSOLVE fats in isooctane; after adding internal standard, ADD potassium hydroxide methanol solution to make the sample methyl-esterified through transesterification. After the reaction is complete, USE sodium sulfate to neutralize the residual potassium hydroxide to avoid saponification of methyl esters. 3 Reagents and materials Unless otherwise stated, the reagents used in this method are analytical regents and the water is the Grade 1 water specified in GB/T 6682. 3.1 Reagents 3.1.1 Hydrochloric acid (HCl). 3.1.2 Ammonia (NH3 · H2O). 3.1.3 Pyrogallic acid (C6H6O3). 3.1.4 Ether (C4H10O). 3.1.5 Petroleum ether. with a boiling range of 30 °C ~ 60 °C. 3.1.6 Ethanol (C2H6O) (95 %). 3.1.7 Methanol (CH3OH). chromatographically pure. 3.1.8 Sodium hydroxide (NaOH). 3.1.9 N-heptane [CH3(CH2)5CH3]. chromatographically pure. 3.1.10 Boron trifluoride methanol solution, with a concentration of 15 %. 3.1.11 Anhydrous sodium sulfate (Na2SO4). 3.1.12 Sodium chloride (NaCl). 3.1.13 Isooctane [(CH3)2CHCH2C(CH3)3]. chromatographically pure. 3.1.14 Sodium bisulfate (NaHSO4). 3.1.15 Potassium hydroxide (KOH). 3.2 Preparation of reagents 3.2.1 Hydrochloric acid solution (8.3 mol/L). WEIGH 250 mL of hydrochloric acid; DILUTE with 110 mL of water; MIX well. It can be placed for 2 months at room temperature. 3.2.2 Ether-petroleum ether mixture (1 + 1). TAKE the same volume of ether and petroleum ether; MIX well for further use. 3.2.3 Sodium hydroxide methanol solution (2 %). TAKE 2 g of sodium hydroxide and to the walls of the flask are mixed into the solution. After the hydrolysis is complete, REMOVE the flask and COOL to room temperature. Acid and alkali hydrolysis method. cheeses. ADD 5 mL of ammonia, MIX well. PLACE the flask in a water bath at 70 °C to 80 °C to hydrolyze for 20 min. SHAKE the flask once every 5 min so that the particles adhering to the walls of the flask are mixed into the solution. Then ADD 10 mL of hydrochloric acid, CONTINUE to hydrolyze for 20 min. SHAKE the flask once every 10 min so that the particles adhering to the walls of the flask are mixed into the solution. After the hydrolysis is complete, REMOVE the flask and COOL to room temperature. 5.2.1.3 Fat extraction ADD 10 mL of 95 % ethanol to the hydrolyzed sample, MIX well. TRANSFER the hydrolyzate in the flask to a separatory funnel; USE 50 mL of ether petroleum ether mixture to rinse the flask and stopper; ADD the rinsing solution to the separatory funnel; COVER the cap. SHAKE for 5 min, STAND for 10 min. COLLECT the ether layer extract to a 250-mL flask. EXTRACT the hydrolyzate three times according to the above procedure. Finally, USE ether petroleum ether mixture to rinse the separatory funnel and COLLECT the rinsing solution in a 250-mL flask. USE rotary evaporator to concentrate to dryness and the residue is the fat extract. 5.2.1.4 Saponification of fats and methyl esterification of fatty acids ADD 8 mL of 2 % sodium hydroxide methanol solution in the fat extract; CONNECT to the reflux condenser; REFLUX in 80 °C ± 1 °C water bath until the oil droplets disappear. ADD 7 mL of 15 % boron trifluoride methanol solution from the top of t... ......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.