GB 14883.4-2016 English PDFUS$119.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. GB 14883.4-2016: Examination of radioactive materials for foods -- Determination of promethium-147 Status: Valid GB 14883.4: Historical versions
Basic dataStandard ID: GB 14883.4-2016 (GB14883.4-2016)Description (Translated English): Examination of radioactive materials for foods -- Determination of promethium-147 Sector / Industry: National Standard Classification of Chinese Standard: C53 Classification of International Standard: 67.040 Word Count Estimation: 6,650 Date of Issue: 2016-08-31 Date of Implementation: 2017-03-01 Older Standard (superseded by this standard): GB 14883.4-1994 Regulation (derived from): Announcement of the State Administration of Public Health and Family Planning 2016 No.11 Issuing agency(ies): National Health and Family Planning Commission of the People's Republic of China, State Food and Drug Administration GB 14883.4-2016: Examination of radioactive materials for foods -- Determination of promethium-147---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. (Food safety national standard - DETERMINATION OF RADIOACTIVE SUBSTANCE -147 IN FOOD) National Standards of People's Republic of China National Food Safety Standard Determination of radioactive substances promethium -147 Issued on. 2016-08-31 2017-03-01 implementation People's Republic of China National Health and Family Planning Commission released ForewordThis standard replaces GB 14883.4-1994 "test radioactive materials for foods - Determination of promethium -147." This standard compared with GB 14883.4-1994, the main changes are as follows. --- Standard name was changed to "national food safety standard radioactive materials for foods - Determination of promethium -147"; --- National food safety standards in accordance with the format of the text has been adjusted; --- Delete Appendix A, Appendix A of the original content is placed in the body of the respective terms. National Food Safety Standard Determination of radioactive substances promethium -1471 ScopeThis standard applies to promethium -147 (147Pm) Determination of various foods. Principle 2 Neodymium and samarium as 147Pm carrier, food ash leaching with nitric acid and hydrogen peroxide, promethium and other heavy rare earth elements in the form of oxalate Lake, then adsorbed coated with titanium - (2-ethylhexyl) phosphoric acid polychlorotrifluoroethylene (referred HDEHP-Kel-F) column. Color paper layer method The 147Pm separated from other rare earth elements. With low background β β measuring instrument measuring the radioactivity 147Pm.3 Reagents and materialsUnless otherwise indicated, the methods used were of analytical grade reagents and water as a water GB/T 6682 regulations. 3.1 Reagents 3.1.1 two - (2-ethylhexyl) phosphoric acid (C16H35O4P). also known as double iso-octyl phosphate, chemically pure. 3.1.2 n-heptane (C7H16). 3.1.3 hydroxylamine hydrochloride (NH2OH · HCl). 3.1.4 anhydrous sodium acetate (C2H3NaO2). 3.1.5 Uranium reagent Ⅲ (C22H18As2N4O14S2). 3.1.6 monochloroacetic acid (C2H3ClO2). 3.1.7 Uranium reagent Ⅰ (C16H11AsN2Na2O11S2). 3.1.8 Ammonium thiocyanate (NH4SCN). 3.1.9 butanone (C4H8O). 3.1.10 absolute ethanol (C2H6O). 3.1.11 hexamethylenetetramine (C6H12N4). 3.1.12 nitric acid (HNO3). 3.1.13 sulfosalicylic acid (C7H6O6S · 2H2O). 3.1.14 ascorbic acid (C6H8O6). 3.1.15 2,4-dinitrophenol (C6H4N2O5). 3.2 reagent preparation 3.2.1 hydroxylamine hydrochloride - sodium acetate buffer. 1L of water was added to hydroxylamine hydrochloride and 9g 10g of anhydrous sodium acetate, pH adjusted with nitric acid solution To 1.5. 3.2.2 a buffer acid - a mixture of uranium reagent Ⅲ. the 1.00g dissolved uranium reagent Ⅲ 120mL1mol/L sodium hydroxide solution. In a 500mL water dissolve 100g acid, mixing the two, diluted with water to 1L. 3.2.3 eluent. Add 2.5g 300mL ammonium thiocyanate in methyl ethyl ketone was added 4mL of water and dissolved, stirring constantly added 3mL of concentrated nitric acid. Use the supernatant. 3.2.4 uranium reagent layer was Ⅰ agent. Weigh 0.10g uranium reagent Ⅰ, dissolved in 35mL saturated aqueous solution of hexamine, diluted with anhydrous ethanol To 100mL, mix, clarified and filtered. When using a volume of about 150mL prosper in the nebulizer. 3.3 Standard 147Pm standard solution. radioactive decay intensity of about 1 × 103/(min · mL). 3.4 Standard Solution Neodymium, samarium standard solution. Weigh accurately spectroscopically pure neodymium oxide (Nd2O3) and samarium oxide (Sm2O3) each 1.0000g, was dissolved in a small amount of concentrated nitric Acid, with 0.5mol/L nitrate formulated into 1L, this solution per ml of stock standard solution containing 1.0mg of each Nd2O3 and Sm2O3. With shift Pipette accurately Pipette 10.0mL standard stock solution was diluted to 100mL with 0.5mol/L nitrate. This solution per milliliter and Nd2O3 Sm2O3 100μg of each standard solution.4 instruments and equipment4.1 chromatographic column. Weigh 3g particle diameter of 180μm ~ 250μm of polychlorotrifluoroethylene powder, dried into a small beaker. Join 6mL 25% of the two - (2-ethylhexyl) phosphoric acid - heptane solution, mix well placed 24h, placed in 80 ℃ ~ 90 ℃ oven drying. use 0.1mol/L nitrate load lower packed with glass wool 25mL acid Buret bed height 13cm ~ 14cm, on top of the bed with a small glass Glass wool. Before use of hydroxylamine hydrochloride 20mLpH1.5 - sodium acetate buffer solution with 1mL/min flow rate through the column. 4.2 paper chromatography tube. diameter 20cm, 100cm tall glass cylinder with a glass cylinder tripod supporting a large glass dish Sheng Put eluent. Put a dish on the glass rod made of a triangular frame for support with a colored layer of paper. Catchy separator tube with perforated vacuum dried Cover seal, cover the hole with a separating funnel with a rubber stopper plugged separating funnel for accession eluent used. For the whole barrel is poured Lotion "steam" saturated, to be hung in the barrel a few soaked with eluent color layer paper. 4.3 colored layer of paper. coated paper with a medium-speed color and cut into 60cm, width of 7.5cm long. After immersion in 15% ammonium nitrate, immediately remove the dry preparation use. Folded from paper at the end of 6cm so anchored in the upper triangular frame. Away from the paper side 7.5cm, 1.5cm from the edge of the pencil lightly Crossed, as a coating liquid analysis reticle. 1cm from the end of the paper with two holes for hanging glass wear aggravated by hook (see Figure 1). Figure 1 colored layer paper 4.4 Spectrophotometer. 4.5 low background β ray measuring instrument. The gas-flow proportional counter (background count rate of not more than 3 counts/min) or other suitable low 147Pm Energy β-ray measuring instruments (such as low background β liquid scintillation counter). Step 5 Analysis Draw 5.1 Operating Curve In Micropipettes Pipette respectively 0mL, 0.2mL, 0.4mL, 0.6mL, 0.8mL, 1.0mL neodymium, samarium standard solution (3.4) into Than six color tube. One drop of each of 6mol/L nitric acid, diluted to 10mL. 5.5.2 The following steps in accordance with the absorbance was measured. To account Computer processing or absorbance made on graph paper - neodymium, samarium content curve. 5.2 Determination of counting efficiency 147Pm various amounts of standard solution (200 decays/min ~ 1500 decays/min) at five 50mL beaker was added thereto in 0.5mL neodymium, samarium standard solution. 5.4.13 analysis in accordance with the source system and under the same conditions were β radioactivity measured in a sample. In computer processing Or at the graph paper β counting rate and the actual radioactivity of the sample drawing, the slope of the line is the counting efficiency 147Pm. 5.3 Sampling and pretreatment Sampling and pretreatment according to the provisions of GB 14883.1. 5.4 Preparation of sample and assay 5.4.1 Weigh 5g ~ 10g (accurate to 0.001g) in 150mL food gray porcelain crucible, accurate added neodymium, samarium standard solution of 1.0mL. Ash moistened with water after adding 5mL ~ 10mL 3mL of nitric acid and hydrogen peroxide, evaporated to dryness on a sand bath, 600 ℃ 30min ashing in a muffle furnace. 5.4.2 cooling to room temperature, 50mL of nitric acid was added, covered with a watch glass and heated to boiling, 5mL of hydrogen peroxide was added dropwise and then heated 15min. from Heart, and the supernatant was poured into a 200mL beaker. The residue was then 40mL of nitric acid and hydrogen peroxide heated 3mL leaching, centrifugation. With 20mL water The residue was washed by centrifugation. The combined supernatant was discarded residue. 5.4.3 added to the supernatant 4g ~ 6g oxalic acid (for a small amount of calcium-containing foods, such as found in oxalate precipitation too little calcium can be added to an appropriate carrier body). The solution was adjusted with ammonia to pH 1.5, water bath 20min, cooled and filtered. Precipitated together with the filter paper into 100mL porcelain crucible. carbon After the burning of high-temperature furnace at 600 ℃ 1h. 5.4.4 cooling to room temperature, 30mL of nitric acid was added and heated to boiling. 2mL ~ 3mL was added dropwise hydrogen peroxide, and heating continued for 15min, and filtered. Successively washed with nitric acid and 10mL water. Insolubles were discarded and the filtrate was collected in the 150mL beaker. 5.4.5 To the filtrate was added 500mg of hydroxylamine hydrochloride and 450mg of anhydrous sodium acetate with aqueous ammonia solution was adjusted to pH 1.5. 5.4.6 The solution flow rate of 2mL/min through a chromatographic column (4.1) with hydroxylamine hydrochloride 20mLpH1.5 - the sodium acetate buffer solution to wash Fandi chromatographic column, discard the effluent. With 40mL2mol/L nitric acid to 1mL/min flow rate for rare earths. Effluent was collected in 100mL beaker. 5.4.7 with aqueous ammonia solution was adjusted to pH 9 to 10. Heated to boiling, cooled to room temperature. Medium speed quantitative filter paper with a pH9 ~ 10 Ammonia water. 5.4.8 precipitated together with the filter paper into 5mL crucible. After charring in a high temperature furnace burning 600 ℃ 20min. After cooling, 10 drops Glass Acid and 2 drops of hydrogen peroxide, sand bath steam until nearly dry. Cooled to room temperature. 5.4.9 instillation of 3 drops 0.1mol/L nitrate, an infrared lamp capillary apply the solution to the colored layer paper coating solution reticle. Then respectively 1 drop and 2 drops of 0.1mol/L nitric crucible washed, the washing liquid is also applied to the reticle. The upper end of the strip of glass hook put emphasis placed chromatography tube Immersed in the eluent containing a large dish. 5.4.10 downstream chromatography time is generally (depending on the room temperature and the degree may be closed barrel) is 40h ~ 80h. 5.4.11 Remove the paper dry. Ⅰ significant uranium reagent layer agent to strip spray until the blue plaque layer up. 5.4.12 Cut neodymium and samarium two blue spots layer, add 15mL crucible (crucible Ⅰ). Cut purple paper neodymium and samarium between locus coeruleus Section, into another crucible (crucible Ⅱ), plus neodymium, samarium standard solution of 0.5mL, after charring two crucibles transferred into a high temperature furnace burning 600 ℃ 20min. Then cool, add 1mL of nitric acid and 2 drops to 3 drops of hydrogen peroxide on the sand bath steam until nearly dry, cool. 5.4.13 with about 10mL1mol/L nitric acid and 10mL water crucible Ⅱ contents were transferred into a 50mL beaker. Adjusted with ammonia Solution to pH 9 to 10, heated to boiling, cooled to room temperature. In pad speed quantitative filter paper (φ20mm) removable funnel filtration, with Ammonia water washed pH9 ~ 10's. Remove the paper, dried under an infrared lamp, β radioactivity measured with a low background β measuring instrument. 5.5 Determination of the chemical recovery 5.5.1 The crucible Ⅰ water contents were transferred to a graduated colorimetric tube, dilute with water to 10mL, shake. 5.5.2 Pipette 5mL solution is placed in a volume of 25mL colorimetric tube, add 0.2mL10% sulfosalicylic acid, 0.2mL freshly prepared 1 drop of 1% ascorbic acid and 2,4-dinitrophenol indicator. With 2mol/L sodium hydroxide solution to yellow, then 0.5mol/L hydrochloric acid And to colorless, diluted with water to 15mL, 5mL added a TCA buffer - Ⅲ uranium reagent mixture. Diluted with water to 25mL, shake uniform. Sheng into 1cm cuvette in the spectrophotometer (λ = 665nm) absorbance was measured. 5.5.3 isolated on the working curve neodymium, samarium micrograms recovered, divided by neodymium, samarium added in an amount, namely chemical yield of 147Pm.6 expression analysisFoods 147Pm radioactivity concentration according to equation (1). A = NM 60WERe-λt (1) Where. A --- foods 147Pm radioactivity concentration in units of becquerels per kilogram (Bq/kg); N --- net count rate of the sample, in units of counts per minute (cpm); M --- fresh ash, in units of grams per kilogram (g/kg); W --- ash samples were analyzed by mass, in grams (g); E --- counting efficiency of 147Pm; R --- chemical recovery; --- 147Pm decay constant [lambda], in units of day (d-1), λ = 0.693/T, T is the half-life of 147Pm, 957.4d; t --- sampling to measure time in days (d).7 OtherUnder typical conditions, the detection limit of the method was 1.2 × 10-2Bq/g ash. ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB 14883.4-2016_English be delivered?Answer: Upon your order, we will start to translate GB 14883.4-2016_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. 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