HJ 632-2011 English PDFUS$239.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. HJ 632-2011: Soil. Determination of Total Phosphorus by alkali fusion. Mo-Sb Anti spectrophotometric method Status: Valid
Basic dataStandard ID: HJ 632-2011 (HJ632-2011)Description (Translated English): Soil. Determination of Total Phosphorus by alkali fusion. Mo-Sb Anti spectrophotometric method Sector / Industry: Environmental Protection Industry Standard Classification of Chinese Standard: Z18 Classification of International Standard: 13.080 Word Count Estimation: 9,918 Date of Issue: 2011-12-06 Date of Implementation: 2012-03-01 Quoted Standard: HJ 613; HJ/T 166 Regulation (derived from): Department of Environmental Protection announcement No. 85 of 2011 Issuing agency(ies): Ministry of Ecology and Environment Summary: This standard specifies the determination of total phosphorus in soil alkali fusion molybdenum blue spectrophotometric method. This standard applies to the determination of total phosphorus in the soil. When the sample volume is 0. 2500g, using 30mm cuvette, the method detection limit is 10. 0mg/kg, detection limit is 40. 0mg/kg. HJ 632-2011: Soil. Determination of Total Phosphorus by alkali fusion. Mo-Sb Anti spectrophotometric method---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. Soil.Determination of Total Phosphorus by alkali fusion.Mo-Sb Anti spectrophotometric method National Environmental Protection Standard of the People's Republic Determination of total phosphorus in soil Alkali fusion-molybdenum antimony anti-spectrophotometry Soil-Determination of Total Phosphorus by alkali fusion– Mo-Sb Anti spectrophotometric method The text shall prevail. Published on.2011-12-06 2012-03-01 implementation release Ministry of Environmental Protection ContentForeword. II 1 Scope..1 2 Normative references..1 3 method principle..1 4 Reagents and materials.1 5 instruments and equipment. 2 6 samples. 2 7 Analysis steps..3 8 Results calculation and representation..3 9 precision and accuracy..4 10 Quality Assurance and Quality Control 4ForewordIn order to implement the "Environmental Protection Law of the People's Republic of China", protect the environment, protect human health, and regulate the measurement of total phosphorus in the soil. Determine the method and formulate this standard. This standard specifies the alkali fusion-molybdenum anti-spectrophotometry for the determination of total phosphorus in soil. This standard is the first release. This standard was formulated by the Science and Technology Standards Department of the Ministry of Environmental Protection. This standard is mainly drafted by. Gansu Provincial Environmental Monitoring Center Station. This standard is verified by. Henan Environmental Monitoring Center Station, Qinghai Environmental Monitoring Center Station, Lanzhou Environmental Monitoring Station, Jinchang Environmental Monitoring Station and Lanzhou Petrochemical Company Monitoring Station. This standard was approved by the Ministry of Environmental Protection on December 6,.2011. This standard has been implemented since March 1,.2012. This standard is explained by the Ministry of Environmental Protection. Determination of total phosphorus in soil - alkali fusion-molybdenum antimony anti-spectrophotometric method1 Scope of applicationThis standard specifies the alkali fusion-molybdenum anti-spectrophotometry for the determination of total phosphorus in soil. This standard applies to the determination of total phosphorus in soil. When the sample amount is 0.2500g and the 30mm cuvette is used, the detection limit of the method is 10.0mg/kg, and the lower limit of determination is 40.0 mg/kg.2 Normative referencesThe contents of this standard refer to the following documents or their terms. For undated references, the valid version is appropriate. Used in this standard. HJ 613 Determination of dry matter and moisture in soils - Gravimetric method HJ/T 166 Technical Specifications for Soil Environmental Monitoring3 Principle of the methodMelted by sodium hydroxide, the phosphorus-containing minerals and organophosphorus compounds in the soil samples are all converted into soluble orthophosphoric acid. The salt is reacted with a molybdenum anti-chromogen to form a phosphorus molybdenum blue under acidic conditions, and the absorbance is measured at a wavelength of 700 nm. In a certain thick Within the range of degrees, the total phosphorus content and absorbance values in the sample are in accordance with Lambert-Beer's law.4 reagents and materialsAnalytical purification reagents that meet national standards were used for analysis unless otherwise stated. Experimental water is freshly prepared Ionic water or distilled water, conductivity (25 ° C) ≤ 5.0 μS/cm. 4.1 Concentrated sulfuric acid. ρ (H2SO4) = 1.84 g/ml. 4.2 Sodium hydroxide. granular, excellent grade. 4.3 Anhydrous ethanol. ρ(CH3CH2OH)=0.789 g/ml. 4.4 Concentrated nitric acid. ρ (HNO3) = 1.51 g/ml. 4.5 Potassium dihydrogen phosphate. excellent grade pure Take appropriate amount of potassium dihydrogen phosphate (KH2PO4) in a weighing bottle, dry at 110 ° C for 2 h, place in a desiccator to cool, prepare use. 4.6 Sulfuric acid solution. c(H2SO4)=3mol/L In 800 ml of water, slowly add 168 ml of concentrated sulfuric acid (4.1) with constant stirring. After the solution is cooled, add water to 1000. Ml, mix. 4.7 Sulfuric acid solution. c(H2SO4)=0.5mol/L In 800 ml of water, slowly add 28 ml of concentrated sulfuric acid (4.1) with constant stirring. After the solution is cooled, add water to 1000 ml. Mix well. 4.8 Sulfuric acid solution. 1+1 Formulated with concentrated sulfuric acid (4.1). 4.9 sodium hydroxide solution. c (NaOH) = 2mol/L Weigh 20.0 g of sodium hydroxide (4.2), dissolve in.200 ml of water, add water to 250 ml after the solution is cooled, and mix. 4.10 Ascorbic acid solution. ρ=0.1 g/ml Weigh 10.0g of ascorbic acid dissolved in an appropriate amount of water, add water to 100ml after dissolution, and mix. The solution is stored in brown glass The bottle is stable for about two weeks at about 4 °C. If the color turns yellow, discard the re-match. 4.11 Ammonium molybdate solution. ρ[(NH4)6 Mo7O24·4H2O)]=0.13 g/ml Weigh 13.0 g of ammonium molybdate dissolved in an appropriate amount of water, dissolve and add water to 100 ml, and mix. 4.12 Potassium bismuth tartrate solution. ρ[K(SbO)C4H4O6·1/2H2O]=0.0035 g/ml Weigh 0.35 g of bismuth potassium tartrate dissolved in an appropriate amount of water, dissolve and add water to 100 ml, and mix. 4.13 Molybdate solution 100 ml of ammonium molybdate solution (4.11) was slowly added to the cooled 300 ml sulfuric acid solution (4.8) with constant stirring. In addition, add 100ml of potassium bismuth tartrate solution (4.12) and mix. The solution was stored in a brown glass bottle at 4 ° C Can be stable for two months. 4.14 Phosphorus standard stock solution (in P). ρ=50.0 mg/L Weigh 0.2197g potassium dihydrogen phosphate (4.5) dissolved in an appropriate amount of water, dissolved and transferred to a 1000ml volumetric flask, then add 5ml Sulfuric acid solution (4.8), add water to the mark and mix. The solution was stored in a brown glass bottle and was stable for six months at 4 °C. 4.15 Phosphorus standard working solution (in P). ρ=5.00 mg/L Take 25.00ml of phosphorus standard stock solution (4.14) in a 250 ml volumetric flask, add water to the mark and mix. The solution Available when used. 4.16 2,4-Dinitrophenol (or 2,6-dinitrophenol) indicator. ρ=0.002 g/ml Weigh 0.2g of 2,4-dinitrophenol (or 2,6-dinitrophenol) dissolved in an appropriate amount of water, dissolve and add water to 100 ml, mix uniform.5 Instruments and equipment5.1 Spectrophotometer. equipped with a 30mm cuvette. 5.2 Muffle furnace. 5.3 Centrifuge. 2500~3500r/min with 50ml centrifuge cup. 5.4 Nickel. The capacity is greater than 30ml. 5.5 Balance. Accuracy is 0.0001g. 5.6 Sample Crushing Equipment. Soil Crusher (or Ball Mill). 5.7 Soil sieve. The pore size is 1mm, 0.149mm (100 mesh). 5.8 with colorimetric tube. 50 ml. 5.9 Common instruments and equipment used in general laboratories.6 samples6.1 Sample collection and preservation Soil samples were collected and stored in accordance with the relevant regulations of HJ/T 166. 6.2 Preparation of samples Place the collected sample in the air-drying tray, spread it into a thin layer of 2~3cm, crush and turn it in time, and pick up the gravel and sand. Gravel, plant debris. Grind with a wooden stick, then remove the debris, smash, mix thoroughly, pass through a 1mm soil sieve, and then take the soil sample Lay a thin layer on kraft paper and divide it into quarters. Use a small spoon to take an equal amount of soil sample in each square (the total amount is greater than 20g), grinding in a soil pulverizer (or ball mill), all through a 0.149mm (100 mesh) soil sieve, mixed After mixing, put it into the grinding bottle and set aside. 6.3 Determination of dry matter content Accurately weigh the appropriate amount of air-dried soil samples and determine the dry matter content according to HJ 613.7 Analysis steps7.1 Preparation of samples Weigh 0.2500g sample (6.2) at the bottom of the nickel crucible, wet the sample with a few drops of absolute ethanol (4.3); then add 2g Sodium hydroxide (4.2) is spread on the surface of the sample, the sample is covered, and the lid is covered; the crucible is placed in a muffle furnace to heat up. When the temperature rose to about 400 ° C, hold for 15 min; then continue to raise the temperature to 640 ° C, hold for 15 min, take out the cooling. again Add 10 ml of water to the crucible and heat to 80 ° C. After the frit dissolves, transfer all the solution in the crucible into a 50 ml centrifuge cup. Wash the mash again with 10 ml of sulfuric acid solution (4.6), transfer the washing solution to a centrifuge cup, and then wash it with a proper amount of water. 3 times, all the washing liquid was transferred into the centrifuge cup, centrifuged at 2500~3500 r/min for 10 min, and the supernatant was completely set after standing. Transfer to a 100ml volumetric flask and dilute to volume with water. Note. When handling a large number of samples, the sputum after adding sodium hydroxide should be temporarily placed in a large dryer to prevent moisture absorption. 7.2 Drawing of the calibration curve Measure 0, 0.50, 1.00, 2.00, 4.00, 5.00ml of phosphorus standard working solution (4.15) in 6 pieces of 50ml In the colorimetric tube, add water to the scale, and the phosphorus content in the standard series is 0.00, 2.50, 5.00, 10.00, 20.00, 25.00 μg, respectively. Then add 2~3 drops of indicator (4.16) to the colorimetric tube, then use sulfuric acid solution (4.7) and sodium hydroxide solution (4.9) Adjust the pH to about 4.4, so that the solution is just yellowish, then add 1.0ml of ascorbic acid solution (4.10) and mix. 30s After adding 2.0 ml of molybdate solution (4.13), mix well and place at 20~30 °C for 15 min. Use a 30mm cuvette, At 700 nm, the absorbance is measured with water as a reference. Correct the absorbance with reagent blank as the ordinate, corresponding phosphorus content (μg) is the abscissa and a calibration curve is drawn. 7.3 Determination Take 10.0ml (or determine the volume according to the sample concentration) sample (7.1) in a 50ml colorimetric tube, add water to Scale. Then perform color development and measurement in the same procedure as drawing the calibration curve (7.2). 7.4 Blank test No soil sample is added, and color development and measurement are carried out according to the same operation steps as preparation of sample (7.1) and measurement (7.3). the amount.8 Calculation and representation of results8.1 Calculation of results The content of total phosphorus in the soil ω (mg/kg) is calculated according to formula (1). [(AA a] V1 Bm Vdmw ω ×= × × × (1) In the formula. Ω--the content of total phosphorus in soil, mg/kg; A--the absorbance value of the sample; 0A - the absorbance value of the blank test; A--the intercept of the calibration curve; V1--sample volumetric volume, ml; b--The slope of the calibration curve. M--sample amount, g; V2--sample volume, ml; Dmw -- the dry matter content (mass fraction) of the soil, %. 8.2 Results representation The measurement results retain three significant figures.9 Precision and accuracy9.1 precision Samples of 28 mg/kg, 400 mg/kg, and 800 mg/kg were measured in 5 laboratories. the relative standard in the laboratory The quasi-bias are. 1.2%~9.4%, 0.3%~2.9%, 0.3%~1.6%; the relative standard deviations between laboratories are. 8.6 %, 3.5%, 1.4%; repeatability limits were. 7.42 mg/kg, 23.6 mg/kg, 21.4 mg/kg; reproducibility limits were. 12.6 mg/kg, 45.4 mg/kg, 38.1 mg/kg. 9.2 Accuracy Five laboratories performed standard test samples of 410±73mg/kg, 323±69mg/kg, and 492±50 mg/kg, respectively. Analytical determination. relative error. 8.3%~16.6%, 3.1%~10.5%, 0.6%~5.5%, relative error final value They are. 13% ± 6.3%, 7.0% ± 7.0%, 4.2% ± 4.2%. The actual samples were spiked and analyzed by 5 laboratories. When the scalar quantity was 100μg, the spiked recovery rates were. 91.2%~103.0%, 91.1%~97.3%, 90.6%~96.0%, the final recoveries of the spiked recovery are. 95.1%±9.2%, 93.8 % ± 5.6%, 93.2 % ± 4.1%. 10 Quality Assurance and Quality Control 10.1 Each batch of samples should be blanked and the results should be below the method detection limit. 10.2 At least 10% of the parallel samples should be determined for each batch of samples. When the number of samples is less than 10, at least one parallel sample should be determined. The relative deviation of the two measurements should not exceed 15%. 10.3 Each batch of samples shall be provided with an intermediate check point. The relative error between the measured value of the intermediate check point and the corresponding point of the calibration curve shall be Not more than 10%. 10.4 When testing each batch of samples, a certified reference material shall be analyzed and its measured value shall be within the guaranteed value range. 10.5 The correlation coefficient of the calibration curve should be greater than or equal to 0.9995. 10.6 At least 10% of the spiked samples shall be determined for each batch of samples. When the number of samples is less than 10, at least one spiked sample shall be determined. The spiked recovery should be between 80 and 120%. ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of HJ 632-2011_English be delivered?Answer: Upon your order, we will start to translate HJ 632-2011_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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