GB 5009.33-2025 English PDFUS$439.00 · In stock
Delivery: <= 4 days. True-PDF full-copy in English will be manually translated and delivered via email. GB 5009.33-2025: National food safety standard - Determination of nitrite and nitrate in foods Status: Valid GB 5009.33: Historical versions
Basic dataStandard ID: GB 5009.33-2025 (GB5009.33-2025)Description (Translated English): National food safety standard - Determination of nitrite and nitrate in foods Sector / Industry: National Standard Classification of Chinese Standard: C53 Word Count Estimation: 22,227 Date of Issue: 2025-09-02 Issuing agency(ies): National Health Commission; State Administration for Market Regulation GB 5009.33-2025: 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/GB5009.33-2025National Standards of the People's Republic of China National Food Safety Standards Determination of nitrite and nitrate in food Published on 2025-09-02 Implemented on 2026-03-02 National Health Commission of the People's Republic of China State Administration for Market Regulation issued ForewordThis standard replaces GB 5009.33-2016 "National Food Safety Standard - Determination of Nitrite and Nitrate in Food". Compared with GB 5009.33-2016, the main changes in this standard are as follows. ---Continuous flow analysis has been added - spectrophotometry has been changed to the third method, and the original third method has been modified to the fourth method; ---The first method modified the sample pretreatment method; ---The second method modifies the sample pretreatment method, the standard solution preparation method, and the reduction efficiency calculation method; ---The detection limit and quantitation limit of the method have been modified. National Food Safety Standards Determination of nitrite and nitrate in food 1.Scope This standard specifies the methods for determining nitrite and nitrate in food. The first method of this standard applies to food products (partially hydrolyzed milk protein formulas, extensively hydrolyzed milk protein formulas, amino acid formulas, and amino acid metabolism products). Determination of nitrite and nitrate in foods for special medical purposes (excluding those with special medical purposes). Methods II and III of this standard are applicable to the determination of nitrite and nitrate in food. Method 4 of this standard is applicable to the determination of nitrates in fresh vegetables and fruits. First method. Ion chromatography 2.Principle After protein precipitation and fat removal, the sample was extracted and purified using potassium hydroxide or sodium hydroxide solution as the eluent. (Anionic...) Separation is achieved using an exchange column, followed by detection with a conductivity detector or ultraviolet detector. Qualitative analysis is based on retention time, while quantification is performed using the external standard method. 3.Reagents and Materials Unless otherwise stated, all reagents used in this method are of analytical grade, and the water is Grade I water as specified in GB/T 6682. 3.1 Reagents 3.1.1 Acetic acid (CH3COOH). chromatographic grade. 3.1.2 Potassium hydroxide (KOH). 3.1.3 Sodium hydroxide (NaOH). 3.1.4 α-Amylase. Enzyme activity ≥1.5U/mg. 3.2 Reagent Preparation 3.2.1 Acetic acid solution (3%). Measure 3 mL of acetic acid into a 100 mL volumetric flask, dilute with water to the mark, and mix well. 3.2.2 Potassium hydroxide solution (1 mol/L). Weigh 5.6 g of potassium hydroxide, dissolve it in freshly boiled and cooled water, and dilute to 100 mL. Mix well. 3.2.3 Sodium hydroxide solution (1 mol/L). Weigh 4.0 g of sodium hydroxide, dissolve it in freshly boiled and cooled water, and dilute to 100 mL. Mix well. 3.3 Standard Products 3.3.1 Sodium nitrite standard (NaNO2, CAS No.. 7632-00-0). Purity ≥ 99%. Or certified by the state and granted a standard substance certificate. The book's nitrite standard. 3.3.2 Sodium nitrate standard (NaNO3, CAS No.. 7631-99-4). Purity ≥ 99%. Or certified by the state and granted a standard substance certificate. Nitrate standard. 3.4 Preparation of Standard Solutions 3.4.1 Sodium nitrite standard stock solution (100 mg/L). Accurately weigh 0.1000 g of sodium nitrite dried to constant weight at 110℃~120℃. Sodium, dissolved in water and diluted to 1000 mL, mixed well, and stored in a refrigerator at 2℃~6℃. Shelf life is 3 months. 3.4.2 Sodium nitrate standard stock solution (100 mg/L). Accurately weigh 0.1000 g of sodium nitrate dried to constant weight at 110℃~120℃, and use... Dissolve and dilute in water to 1000 mL, mix well, and store in a refrigerator at 2℃~6℃. Shelf life is 3 months. 3.4.3 Intermediate Standard Solution of Sodium Nitrite and Sodium Nitrate (2.00 mg/L). Accurately transfer portions of the standard stock solutions of sodium nitrite and sodium nitrate to each... Add 2.00 mL to a 100 mL volumetric flask and dilute to the mark with water. Prepare fresh before use. 3.4.4 Mixed standard solution of sodium nitrite and sodium nitrate. Transfer the intermediate solution of the mixed standard of sodium nitrite and sodium nitrate, dilute it stepwise with water to prepare... A series of standard solutions with mass concentrations of 0 mg/L, 0.0100 mg/L, 0.0200 mg/L, 0.0500 mg/L, 0.100 mg/L, and... 0.200 mg/L, 0.500 mg/L, 1.00 mg/L and 2.00 mg/L. Prepare immediately before use. Note. The range of the standard curve can be adjusted according to the content of the target analyte in the sample, and it should include at least 5 concentration levels (excluding zero). 3.5 Materials 3.5.1 Membrane needle filter. water-based, 0.22μm. 3.5.2 C18 purification column. 1 mL, or equivalent column. Activate with 10 mL methanol and 15 mL water sequentially before use. 3.5.3 Ag purification column. Column capacity 2.0 ion equivalent to 2.2 ion equivalents, or equivalent column. Activate with 10 mL of water before use. 3.5.4 Na purification column. Column capacity 2.0 ion equivalent ~ 2.2 ion equivalent, or equivalent column. Activate with 10 mL of water before use. 4.Instruments and Equipment 4.1 Ion chromatograph. equipped with a conductivity detector and suppressor, or an ultraviolet detector. 4.2 Food grinder. 4.3 Ultrasonic cleaner. 4.4 Electronic balance. sensitivity of 0.1 mg and 0.01 g. 4.5 Centrifuge. speed ≥ 10000 r/min. 5.Analysis Steps 5.1 Sample Preparation and Storage 5.1.1 Sample Preparation 5.1.1.1 Liquid or semi-solid samples. Take an appropriate amount of sample and mix it thoroughly by stirring or shaking. 5.1.1.2 Solid powder samples. Take an appropriate amount of sample and mix it thoroughly by means of shaking or other methods. 5.1.1.3 Cheese. Take an appropriate amount of sample and grind it into a uniform slurry. To avoid moisture loss, avoid generating excessive heat during the grinding process. 5.1.1.4 Other solid samples. Take an appropriate amount of sample and crush it into a uniform powder or make it into a slurry for later use. 5.1.2 Sample Storage 5.1.2.1 Perishable samples such as fruits, vegetables, meat, and aquatic products should be stored at -18℃ or below. 5.1.2.2 Other samples shall be stored in accordance with the product's storage conditions. 5.2 Sample Extraction 5.2.1 Milk and dairy products, infant formula, infant formula for special medical purposes, formula for special medical purposes, bird's nest and its products Product. Weigh 10g of liquid sample and 1g~2.5g of other samples (accurate to 0.01g), place them in a 150mL stoppered conical flask, and add water. 80 mL, shake well, sonicate for 30 min (heat if necessary to dissolve or fully swell), remove and let stand at room temperature, then quantitatively transfer to a 100 mL volumetric precipitate. Add 2 mL of 3% acetic acid solution to a volumetric flask (adjust the amount as needed based on precipitation results), dilute to the mark with water, and mix well. Transfer to... A 250 mL stoppered iodine flask was placed at 4 °C for 20 min, then removed and allowed to cool to room temperature. A portion of the solution was filtered through filter paper, and the filtrate was... Centrifuge at 10000 r/min for 15 min, and keep the supernatant for later use. 5.2.2 Easily gelatinized high starch content samples. Weigh 2.5g of the sample (accurate to 0.01g), place it in a 150mL stoppered conical flask, and add α- Add 0.2g of amylase (the amount of enzyme can be adjusted according to the starch content) to 80mL of water, shake well, and incubate at 55℃ for 30min. (The process is repeated in the original text.) "Room temperature" is the same as in 5.2.1. 5.2.3 Other Samples. Weigh 2g~10g of the sample (accurate to 0.01g), place it in a 150mL stoppered conical flask, add 80mL of water, and stir until... Acoustic extraction was performed for 30 minutes, with shaking every 5 minutes to ensure complete dispersion of the sample. The sample was then placed in a 75°C water bath for 5 minutes, and then removed and placed in a cool, dry place. "Warm" begins the same operation as in 5.2.1. 5.3 Sample Cleaning Take approximately 15 mL of the prepared solution from 5.2.1 to 5.2.3, pass it through a 0.22 μm aqueous filter membrane syringe filter and a C18 column, discarding the first 3 mL (if...). If the chloride ion concentration is greater than 100 mg/L or the target analyte is interfering, the sample must be passed sequentially through a syringe filter, a C18 column, an Ag column, and a Na column, discarding the preceding filters. Collect 7 mL of the eluent for testing. 5.4 Blank Test Except for not adding a sample, the other operations are the same as those for adding a sample. 5.5 Instrument Reference Conditions 5.5.1 Column. Hydroxide-selective, compatible with gradient-eluting divinylstyrene-ethylstyrene copolymer matrix, alkanoyl quaternary... High-capacity anion exchange column with ammonium salt functional groups, 4mm × 250mm (with guard column 4mm × 50mm), or equivalent performance ion exchange column. Spectral column. 5.5.2 Eluent. Potassium hydroxide solution or sodium hydroxide solution, concentration 6 mmol/L~70 mmol/L. Elution gradient. 6 mmol/L for 30 min, 70 mmol/L for 5 min, 6 mmol/L for 5 min; flow rate 1.0 mL/min. When chromatographic interference exists, the following elution methods can be selected. Potassium hydroxide or sodium hydroxide solution, concentration 5 mmol/L to 50 mmol/L. Elution gradient 5 mmol/L. 33min, 50mmol/L5min, 5mmol/L5min; flow rate 1.3mL/min. 5.5.3 Detector. Conductivity detector, with a detection cell temperature of 35℃; or ultraviolet detector, with a detection wavelength of 226nm. 5.5.4 Injection volume. 50 μL (can be adjusted according to the content of the analyte ions in the sample). 5.6 Measurement 5.6.1 Construction of Standard Curve Inject the standard series of working solutions into the ion chromatograph (see Appendix A, Figure A.1 for standard chromatograms), with the concentration of the standard working solution being... A standard curve is plotted with the horizontal axis representing the peak height or peak area as the vertical axis. 5.6.2 Determination of Sample Solution Inject blank and sample solutions into the ion chromatograph to obtain peak heights or peak areas for the blank and sample solutions. Then, obtain the peak values of the target solution based on the standard curve. The mass concentration of sodium nitrite or sodium nitrate in the test solution. ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB 5009.33-2025_English be delivered?Answer: Upon your order, we will start to translate GB 5009.33-2025_English as soon as possible, and keep you informed of the progress. The lead time is typically 2 ~ 4 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of GB 5009.33-2025_English with my colleagues?Answer: Yes. The purchased PDF of GB 5009.33-2025_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. 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