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GB 5009.137-2016 PDF in English


GB 5009.137-2016 (GB5009.137-2016) PDF English
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GB 5009.137-2016English80 Add to Cart 0-9 seconds. Auto-delivery. National food safety standard -- Determination of antimony in foods Valid
GB/T 5009.137-2003English239 Add to Cart 3 days Determination of antimony in foods Obsolete
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GB 5009.137-2016: PDF in English

GB 5009.137-2016 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA National Food Safety Standard - Determination of Antimony 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 ... 3  1 Application Scope ... 4  2 Principle ... 4  3 Reagents and Materials ... 4  4 Apparatus ... 6  5 Analytical Procedures ... 6  6 Expression of Analytical Results ... 8  7 Precision ... 9  8 Others ... 9  Annex A Temperature Programming of Microwave Digestion ... 10  National Food Safety Standard - Determination of Antimony in Foods 1 Application Scope This Standard specifies the hydride atomic fluorescence spectrometric method for the determination of antimony in foods. This Standard applies to the determination of antimony in foods. 2 Principle After the sample is digested through acid and heating, in the acidic medium, antimony in the sample reacts with sodium borohydride or potassium borohydride to produce volatile antimony hydride; use argon as the carrier gas to lead antimony hydride into an electric heating quartz atomizer for atomization; under the exposure to antimony hollow cathode lamp, the ground-state antimony atom is excited to the upper-state, and then return to the ground-state from the upper-state; it emits fluorescence of a characteristic wavelength whose fluorescent strength is in direct proportion to antimony content; and quantitate in accordance with the standard series. 3 Reagents and Materials Unless specified otherwise, all reagents used in this method are guaranteed reagents; and all water is grade-2 water specified in GB/T 6682. 3.1 Reagents 3.1.1 Nitric acid (HNO3). 3.1.2 Hydrogen peroxide (H2O2). 3.1.3 Hydrochloric acid (HCl). 3.1.4 Sulfuric acid (H2SO4). 3.1.5 Perchloric acid (HClO4). 3.1.6 Thiocarbamide [(NH2)2CS]. analytically pure. 3.1.7 Potassium iodide (KI). analytically pure. 3.1.8 Ascorbic acid (C6H8O6). analytically pure. 3.1.9 Potassium borohydride (KBH4) or sodium borohydride (NaBH4). 3.1.10 Potassium hydroxide (KOH) or sodium hydroxide (NaOH). 3.2 Preparation of reagents 3.2.1 Nitric acid-perchloric acid mixed acid (10 + 1). measure 500 ml of nitric acid and 50 ml of perchloric acid; and mix up. 3.2.2 Hydrochloric acid (1 + 9). measure 50 ml of hydrochloric acid; add into 450 ml of water; and mix up. 3.2.3 Thiocarbamide-ascorbic acid solution. weigh 10 g of thiocarbamide and 10 g of ascorbic acid; dissolve into 100 ml of water; and mix up. 3.2.4 Thiocarbamide-potassium iodide solution. weigh 2 g of thiocarbamide and 10 g of potassium iodide; dissolve in 100 ml of water; and mix up. 3.2.5 Potassium hydroxide solution (2 g/l). weigh 1 g of potassium hydroxide; dissolve in 500 ml of water; mix up; and prepare it immediately before use. Potassium hydroxide in the solution may be replaced with sodium hydroxide. 3.2.6 Potassium borohydride alkali solution (20 g/l). weigh 10 g of potassium borohydride; dissolve in 500 ml of potassium hydroxide solution (2 g/l); mix up; and prepare immediately before preparation. Potassium borohydride in the solution may also be replaced with sodium borohydride of an equal molar ratio. 3.3 Standard substance Antimony standard solution. 1 000 mg/l. Or an antimony standard solution of a certain concentration which has been certified by the state and granted the certificate of standard substance. 3.4 Preparation of standard solutions 3.4.1 Antimony standard intermediate solution (100 mg/l). accurately absorb 1 ml of antimony standard solution (1 000 mg/l) to pour into a 10 ml volumetric flask; add water dropwise to volume; and mix up. 3.4.2 Antimony standard working solution (1.00 mg/l). accurately absorb 1 ml of antimony standard intermediate solution (100 mg/l) to pour into a 100 ml volumetric flask; add water dropwise to volume; and mix up. 3.4.3 Antimony standard serial solutions. accurately absorb 0 ml, 0.100 ml, 0.200 ml, 0.400 ml, 1.00 ml and 2.00 ml of antimony standard working solution to pour into 100 ml volumetric flasks respectively; after adding a small amount of water for dilution, add 10 ml of hydrochloric acid solution (1 + 9) and 10 ml of thiocarbamide-potassium iodide solution or thiocarbamide-ascorbic acid solution; add water dropwise to volume; and mix up. The mass concentrations of the antimony standard serial solutions are 0 μg/l, Adjust the instrument to the optimum conditions of performance with the reference conditions for the instrument. photomultiplier voltage, 300 V; the hollow cathode lamp current, 60 mA; the atomizer height, 8 mm; the carrier gas flow, 300 ml/min. Adjust to the optimum conditions in accordance with the performance of each instrument. 5.4 Plotting of standard curves Set the optimum conditions of the instrument; raise the furnace temperature to the required temperature; and start measurement after stabilizing for 20 min ~ 30 min. Use the hydrochloric acid (5%) as the carrier, potassium borohydride alkali solution (20 g/l) as the reducer; continuously use the standard serial solutions introduced using a zero tube; after the readings become stable, lead the antimony standard serial solution into the instrument from higher concentration to lower concentration; and determine the fluorescence value. Plot the standard curve using the mass concentration of the antimony standard serial solutions as the abscissa and the corresponding fluorescence value as the ordinate. NOTE If an automatic sample introduction device is available, the programmed automatic dilution may also be used for the preparation of standard series. 5.5 Determination of sample solution Under the same test conditions as those for the determination of the standard solution series, lead the blank solution and test solution into the instrument respectively; determine the fluorescence values; and compare with those of the standard series for quantitation. 6 Expression of Analytical Results The content of antimony in samples is calculated in accordance with Formula (1). where, X--the content of antimony in sample, in mg/kg or mg/l; ρ--the mass concentration of antimony in sample solution, in μg/l; ρ0--the mass concentration of antimony in blank solution, in in μg/l; V--the constant volume of sample digestive juice, in ml; m--the weight or transferred volume of sample, in g or ml; 1 000--the conversion coefficient. ......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.