GB 31604.25-2016 PDF EnglishUS$70.00 · In stock · Download in 9 seconds
GB 31604.25-2016: National standard for food safety - Determination of chromium migration quantity in food contact materials and products Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid
Similar standardsGB 31604.25-2016: National standard for food safety - Determination of chromium migration quantity in food contact materials and products---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/GB31604.25-2016 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA National standard for food safety - Determination of chromium migration quantity in food contact materials and products Issued on: OCTOBER 19, 2016 Implemented on: APRIL 19, 2017 Issued by. National Health and Family Planning Commission of the People’s Republic of China 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 ContentsForeword ... 4 1 Scope ... 5 Method I Graphite furnace atomic absorption spectrometry ... 5 2 Principle... 5 3 Reagents and materials ... 5 4 Instruments and equipment ... 7 5 Analytical procedures ... 7 6 Expression of analysis results ... 8 7 Precision... 8 8 Others ... 8 Method II Inductively coupled plasma mass spectrometry ... 8 Method III Inductively coupled plasma atomic emission spectrometry ... 8 Method IV Diphenylcarbazide colorimetry ... 8 9 Principle... 8 10 Reagents and materials... 9 11 Instruments and equipment ... 10 12 Analytical procedures ... 11 13 Expression of analysis results ... 12 14 Precision ... 12 15 Others ... 12 Annex A ... 13ForewordThe determination of chromium migration quantity in GB/T 5009.80-2003 Method for analysis of hygienic standard of polytetrafluorethylene coating for inner wall of food container, GB/T 5009.81-2003 Method for analysis of hygienic standard of stainless steel food containers and table wares, SN/T 2597-2010 Determination of lead, cadmium, chromium, arsenic, antimony, germanium migration quantity in polymer for food contact materials - Inductively coupled plasma atomic emission spectrometry method and SN/T 2829-2011 Food contact materials for export - Metal materials - Determination of migrant heavy metals in food simulant - Inductively coupled plasma atomic emission spectrometric method is substituted by this Standard. Compared with GB/T 5009.81-2003, the major changes in this Standard are as follows. — MODIFY the standard name as “National standard for food safety - Determination of chromium migration quantity in food contact materials and products”; — ADD the inductively coupled plasma mass spectrometry; and — ADD the inductively coupled plasma atomic emission spectrometry. National standard for food safety - Determination of chromium migration quantity in food contact materials and products1 ScopeThis Standard specifies the graphite furnace atomic absorption spectrometry, inductively coupled plasma mass spectrometry, inductively coupled plasma atomic emission spectrometry, and diphenylcarbazide colorimetry for the determination of chromium migration quantity in food contact materials and their products after immersed in food simulant. This Standard is applicable to the determination of chromium migration quantity in food contact materials and their products. Method I Graphite furnace atomic absorption spectrometry2 PrincipleUSE food simulant to immerse the sections expected to be in contact with the food in the food contact materials and products. The soaking solution is atomized by a graphite furnace. The absorbance determined at 357.9nm is proportional to the chromium content within a certain concentration range. COMPARE with the standard series for quantitation.3 Reagents and materialsUnless otherwise indicated, the reagents and water used in this method are guaranteed reagents and Type II reagent grade water specified in GB/T 6682, respectively. 3.1 Reagents 3.1.1 Nitric acid (HNO3). 3.1.2 Ammonium dihydrogen phosphate (NH4H2PO4).4 Instruments and equipmentNote. All glassware needs to be soaked in nitric acid solution (1 + 5) overnight. USE tap water to wash repeatedly. RINSE with water eventually. 4.1 Graphite furnace atomic absorption spectrometer. equipped with a graphite furnace atomizer and a chrome hollow cathode lamp. 4.2 Analytical balance. with a sensibility of 0.1mg.5 Analytical procedures5.1 Pretreatment of sample CARRY out the migration test based on the intended use and conditions of use of the samples to be tested, and in accordance with the migration test methods and test conditions specified in GB 5009.156 and GB 31604.1. MIX the soaking solution fully and evenly. TAKE some of the soaking solution for analysis. If the soaking solution is neutral or basic, ADD appropriate amount of nitric acid so that the concentration of nitric acid in the test solution is about 5% (volume fraction). In the meantime, CARRY out the sample blank test. 5.2 Determination 5.2.1 Instrument reference conditions SEE Table A.1 for the instrument reference conditions. 5.2.2 Preparation of standard curve TAKE 10μL of chromium standard series solution and 5μL of ammonium dihydrogen phosphate solution (20g/L), respectively (optimal injection volume can be determined according to the instruments in use). In the meantime, INJECT into a graphite furnace for the determination of absorbance. PREPARE the standard curve by taking the concentrations of standard series as x- coordinates and the corresponding absorbance as y-coordinates. 5.2.3 Determination of sample solution TAKE 10μL of blank solution and sample soaking solution as well as 5μL of ammonium dihydrogen phosphate solution (20g/L), respectively (optimal injection volume can be determined according to the instruments in use). In the meantime, INJECT into a graphite furnace. DETERMINE its absorbance after atomization. COMPARE with the standard series for quantitation.12 Analytical procedures12.1 Pretreatment of sample Same as Subclause 5.1. 12.2 Determination 12.2.1 Preparation of standard curve DRAW 0mL, 0.250mL, 0.500mL, 1.00mL, 1.50mL, 2.00mL, 2.50mL and 3.00mL of chromium standard solution. TRANSFER to a 50.0mL volumetric flask, respectively. ADD the corresponding food simulant to the scale. TRANSFER standard series solution to a 100mL conical flask. ADD two glass beads and several drops of sulfuric acid solution (2.5mol/L) and potassium permanganate solution (3g/L). MIX evenly. BOIL to about 30mL [after the reddish color disappears, ADD potassium permanganate solution (3g/L) again until the reddish color appears]. After cooling, ADD 25.0mL of urea solution (200g/L). MIX evenly. Dropwise ADD sodium nitrite solution (100g/L) until the reddish color disappears. ADD saturated sodium hydroxide solution until the mixture is basic (pH = 9). LET it stand for 2h. FILTER afterwards. ADD water to filtrate to 100mL. MIX evenly. TAKE 20.0mL of this solution. ADD it to a 25mL colorimetric tube. ADD 1mL of sulfuric acid solution (2.5mol/L) and 1mL of sodium pyrophosphate solution (50g/L). MIX evenly. ADD 2mL of diphenylcarbazide solution. ADD water to 25.0mL. MIX evenly. LET it stand for 5min. DETERMINE the absorbance at 540nm. PREPARE the standard curve by taking the absorbance as y-coordinates and the chromium mass as x-coordinates. 12.2.2 Determination of sample solution TAKE 50.0mL of sample soaking solution. ADD it to a 100mL conical flask. ADD two glass beads and several drops of sulfuric acid solution (2.5mol/L) and potassium permanganate solution (3g/L). MIX evenly. BOIL to about 30mL [after the reddish color disappears, ADD potassium permanganate solution (3g/L) again until the reddish color appears]. After cooling, ADD 25.0mL of urea solution (200g/L). MIX evenly. Dropwise ADD sodium nitrite solution (100g/L) until the reddish color disappears. ADD saturated sodium hydroxide solution until the mixture is basic (pH = 9). LET it stand for 2h. FILTER afterwards. ADD water to filtrate to 100mL. MIX evenly. TAKE 20.0mL of this solution. ADD it to a 25mL colorimetric tube. ADD 1mL of sulfuric acid solution (2.5mol/L) and 1mL of sodium pyrophosphate solution (50g/L). MIX evenly. ADD 2mL of diphenylcarbazide solution. ADD water to 25.0mL. MIX evenly. LET it stand for 5min. DETERMINE the absorbance at 540nm. In the meantime, CARRY out the sample blank test. ......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 31604.25-2016 be delivered?Answer: The full copy PDF of English version of GB 31604.25-2016 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 31604.25-2016_English with my colleagues?Answer: Yes. The purchased PDF of GB 31604.25-2016_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. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. www.ChineseStandard.us -- GB 31604.25-2016 -- Click this link and select your country/currency to pay, the exact amount in your currency will be printed on the invoice. Full PDF will also be downloaded/emailed in 9 seconds.How to buy and download a true PDF of English version of GB 31604.25-2016?A step-by-step guide to download PDF of GB 31604.25-2016_EnglishStep 1: Visit website https://www.ChineseStandard.net (Pay in USD), or https://www.ChineseStandard.us (Pay in any currencies such as Euro, KRW, JPY, AUD).Step 2: Search keyword "GB 31604.25-2016". Step 3: Click "Add to Cart". If multiple PDFs are required, repeat steps 2 and 3 to add up to 12 PDFs to cart. Step 4: Select payment option (Via payment agents Stripe or PayPal). Step 5: Customize Tax Invoice -- Fill up your email etc. Step 6: Click "Checkout". Step 7: Make payment by credit card, PayPal, Google Pay etc. After the payment is completed and in 9 seconds, you will receive 2 emails attached with the purchased PDFs and PDF-invoice, respectively. Step 8: Optional -- Go to download PDF. Step 9: Optional -- Click Open/Download PDF to download PDFs and invoice. See screenshots for above steps: Steps 1~3 Steps 4~6 Step 7 Step 8 Step 9 |
