GB 5009.33-2016 PDF EnglishUS$115.00 · In stock · Download in 9 seconds
GB 5009.33-2016: National food safety standard - Determination of Nitrite and Nitrate in Foods Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid GB 5009.33: Historical versions
Similar standardsGB 5009.33-2016: National food safety standard - Determination of Nitrite and Nitrate in Foods---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GB5009.33-2016GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA National Food Safety Standard - Determination of Nitrite and Nitrate 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; State Food and Drug Administration of the People’s Republic of China. Table of ContentsForeword... 3 1 Scope... 4 Method I Ion Chromatography... 4 2 Principle... 4 3 Reagents and Materials... 4 4 Instruments and Equipment... 5 5 Analytical Procedures... 6 6 Expression of Analysis Results... 8 7 Precision... 9 8 Others... 9 Method II Spectrophotometry... 9 9 Principle... 9 10 Reagents and Materials... 10 11 Instruments and Equipment... 12 12 Analytical Procedures... 15 13 Expression of Analysis Results... 17 14 Precision... 18 15 Others... 18 Method III Determination of Nitrate in Vegetables and Fruits - UV Spectrophotometry... 18 16 Principle... 18 17 Reagents and Materials... 19 18 Instruments and Equipment... 20 19 Analytical Procedures... 20 20 Calculation Result... 21 21 Precision... 21 22 Others... 21 Appendix A Chromatogram of Nitrite and Nitrate... 22ForewordThis Standard is drafted as a replacement of GB 5009.33-2010 “National Food Safety Standard - Determination of Nitrite and Nitrate in Foods”, NY/T 1375-2007 “Determination of Nitrite and Nitrate in Plant Product - Ion Chromatography Method”, NY/T 1279-2007 “Determination of Nitrate in Vegetables and Fruits - UV Spectrophotometry”, and SN/T 3151-2012 “Determination of Nitrite and Nitrate in Export Foods - Ion Chromatography Method”. In comparison with GB 5009.33-2010, there are several main modifications as follows. -- Previous Method II and Method III are combined into Method II; -- The method of UV spectrophotometry is added to the determination of nitrate in vegetables and fruits. National Food Safety Standard - Determination of Nitrite and Nitrate in Foods1 ScopeThis Standard specifies the method of determining nitrite and nitrate in foods. This Standard is applicable to the determination of nitrite and nitrate in foods. Method I -- Ion Chromatography2 PrinciplePrecipitate protein and remove fat from the sample; adopt the corresponding method to extract and purify; take potassium hydroxide solution as the eluent; adopt anion exchange column for separation; take conductance detector or UV detector for detection. Determine the nature with the retention time and quantify with the external standard method.3 Reagents and MaterialsUnless otherwise indicated, the reagents adopted under this method are of analytical purity. The water is first-grade water as specified in GB/T 6682. 3.1 Reagents 3.2 Preparation of Reagents 3.2.1 Acetic acid solution (3%). weigh-take 3 mL of acetic acid, place it in 100 mL volumetric flask. Add water to dilute to the constant volume; mix it up. 3.2.2 Potassium hydroxide solution (1 mol/L). weigh-take 6 g of potassium hydroxide; dissolve it in cold water that’s newly boiled; dilute to 100 mL; mix it up. 3.3 Standards 3.4 Preparation of Standard Solutions 3.4.1 Standard stock solution of nitrite (100 mg/L, calculated by NO2-, same as below). accurately weigh-take 0.1500 g of sodium nitrite that’s dried to constant weight under 110 °C~120 °C. Add water to dissolve it; transfer it to 1,000 mL volumetric flask. 3.4.2 Standard stock solution of nitrate (1,000 mg/L, calculated by NO3-, same as below). 3.4.3 Standard mixed intermediate solution of nitrite and nitrate. accurately remove-take 1.0 mL of standard stock solution of nitrite ion (NO2-) and 1.0 mL of standard stock solution of nitrate ion (NO3-); place it in 100 mL volumetric flask.4 Instruments and Equipment4.1 Ion chromatograph. equipped with conductance detector and suppressor, or UV detector, high-capacity anion exchange column, 50 μL quantitative cup. 4.2 Food grinder. 4.4 Analytical balance. division value. 0.1 mg and 1 mg. 4.5 Centrifuge. rotating speed ≥10,000 r/min, equipped with 50 mL centrifuge tube. 4.6 0.22 μm water filter needle filter. 4.7 Purification column. include C18 column, Ag column and Na column or equivalent column.5 Analytical Procedures5.1 Pre-processing of Samples 5.2 Extraction 5.2.1 Plant samples, such as vegetable and fruit. weigh-take 5 g (accurate to 0.001 g, the weight can be properly adjusted, same as below) of sample; place it in 150 mL conical flask with a plug; add 80 mL of water, 1 mL of 1 mol/L potassium hydroxide solution. 5.2.5 Milk powder and cottage cheese. weigh-take 2.5 g (accurate to 0.01 g) of sample, place it in 100 mL conical flask with a plug; add 80 mL of water, mix it up. Start ultrasonic extraction for 30 min. Take it out and wait till it reaches the room temperature. Quantitatively transfer it into 100 mL volumetric flask; add 2 mL of 3% acetic acid solution. Add water to dilute to the constant volume. Place it under 4 °C for 20 min; take it out and wait till it reaches the room temperature. Use filter paper to filter the solution; reserve the filtrate for later usage. 5.3 Instrument Reference Conditions 5.3.1 Chromatographic column. hydroxide selectivity, divinylbenzene-ethyl styrene copolymer matrix that’s compatible with gradient elution, high-capacity anion exchange column of alkyl quaternary ammonium salt functional group, 4 mm x 250 mm (with guard column 4 mm x 50 mm), or ion chromatographic column with equivalent performance. 5.3.2 Eluent 5.3.2.1 Potassium hydroxide solution, concentration. 6 mmo/L~70 mmol/L; elution gradient. 6 mmol/L 30 min, 70 mmol/L 5 min, 6 mmol/L 5 min; flow rate. 1.0 mL/min. 5.4 Determination 5.4.1 Standard Curve Inject the standard series of working fluid into ion chromatograph respectively; obtain the chromatogram of the standard series of working fluid under different concentration; determine corresponding peak height (μS) or peak area; take the concentration of the standard series of working fluid as x-coordinate, and peak height (μS) or peak area as y-coordinate. 5.4.2 Determination of Sample Solution Inject blank solution and sample solution into ion chromatograph; obtain the peak height (μS) or peak area of blank solution and sample solution. Obtain the concentration of nitrite ion or nitrate ion in the test solution in accordance with the standard curve.6 Expression of Analysis ResultsThe content of nitrite ion or nitrate ion in the sample shall be calculated in accordance with Formula (1).7 PrecisionThe absolute difference between the two independent determination results obtained under repeatability conditions shall not exceed 10% of the arithmetic mean value.8 OthersThe detection limit of nitrite and nitrate is 0.2 mg/kg and 0.4 mg/kg respectively in Method I.9 PrincipleAdopt naphthalene ethylenediamine hydrochloride method to determine nitrite; adopt cadmium column reduction method to determine nitrate.10 Reagents and MaterialsUnless otherwise indicated, the reagents adopted under this method are of analytical purity. The water is first-grade water as specified in GB/T 6682. 10.1 Reagents 10.2 Preparation of Reagents 10.3 Standards 10.3.1 Sodium nitrite (NaNO2, CAS No.. 7632-00-0). reference reagents, or standard nitrite solution supported by Reference Material Certificate. 3.3.2 Sodium nitrate (NaNO3, CAS No.. 7631-99-4). reference reagents, or standard nitrate solution supported by Reference Material Certificate. 10.4 Preparation of Standard Solutions 10.4.1 Standard solution of sodium nitrite (200 μg/mL, calculated by sodium nitrite). accurately weigh-take 0.1000 g of sodium nitrite that’s dried to constant weight under 110 °C~120 °C. Add water to dissolve it; transfer it to 500 mL volumetric flask. Add water to dilute to the constant volume; mix it up. 10.4.4 Standard working solution of sodium nitrate (5.0 μg/mL, calculated by sodium nitrite). before usage, extract 2.50 mL of standard solution of sodium nitrate; place it in 100 mL volumetric flask. Add water to dilute to the constant volume. ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of English version of GB 5009.33-2016 be delivered?Answer: The full copy PDF of English version of GB 5009.33-2016 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice.Question 2: Can I share the purchased PDF of GB 5009.33-2016_English with my colleagues?Answer: Yes. The purchased PDF of GB 5009.33-2016_English will be deemed to be sold to your employer/organization who actually paid for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. 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