HOME   Cart(2)   Quotation   About-Us Policy PDFs Standard-List
www.ChineseStandard.net Database: 189760 (1 Nov 2025)

GB 25588-2010 English PDF

US$329.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email.
GB 25588-2010: National food safety standards of food additive potassium carbonate
Status: Valid
Standard IDContents [version]USDSTEP2[PDF] delivered inStandard Title (Description)StatusPDF
GB 25588-2010English329 Add to Cart 3 days [Need to translate] National food safety standards of food additive potassium carbonate Valid GB 25588-2010

PDF similar to GB 25588-2010


Standard similar to GB 25588-2010

GB 25576   GB 25577   GB 25585   GB 25581   

Basic data

Standard ID GB 25588-2010 (GB25588-2010)
Description (Translated English) National food safety standards of food additive potassium carbonate
Sector / Industry National Standard
Classification of Chinese Standard X42
Classification of International Standard 67.220.20
Word Count Estimation 14,124
Date of Issue 2010-12-21
Date of Implementation 2011-02-21
Regulation (derived from) Ministry of Health Bulletin No. 19 of 2010
Issuing agency(ies) Ministry of Health of the People's Republic of China
Summary This Chinese standard applies to electrolysis and ion exchange method were food additive potassium carbonate.

GB 25588-2010: National food safety standards of food additive potassium carbonate

---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.
National food safety standards of food additive potassium carbonate National Food Safety Standard Food additive potassium carbonate Issued on. 2010-12-21 2011-02-21 implementation National Standards of People's Republic of China People's Republic of China Ministry of Health issued

Foreword

Appendix A of this standard is a normative appendix. National Food Safety Standard Food additive potassium carbonate

1 Scope

This standard applies to electrolysis and ion exchange method obtained food additive potassium carbonate.

2 Normative references

The standard file referenced in the application of this standard is essential. For dated references, only the edition date of the note This applies to this standard. For undated references, the latest edition (including any amendments) applies to this standard.

3 formula and relative molecular mass

Formula 3.1 K2CO3 3.2 relative molecular mass 138.20 (according to 2007 international relative atomic mass) 4. Technical Requirements 4.1 Sensory requirements. comply with Table 1. Table 1 Sensory requirements Project requires test methods Color White take appropriate sample is placed in a beaker 50mL watch in natural light Observing the color and texture. Crystalline powder or granular state organization 4.2 Physical indicators. to comply with Table 2. Table 2. Physical and chemical indicators Item Index Test Method Potassium carbonate (dry basis), w /% ≥ 99.0 Appendix A A.4 Chloride (KCl dollars) (dry basis), w /% ≤ 0.015 Appendix A A.7 Sulfur compounds (in terms K2SO4) (dry basis), w /% ≤ 0.01 Appendix A A.8 Iron (Fe) (dry basis), w /% ≤ 0.0010 A.9 in Appendix A Water insoluble matter (dry basis), w /% ≤ 0.02 Appendix A A.10 Heavy metals (Pb)/(mg/kg) ≤ 10 Appendix A A.11 Arsenic (As)/(mg/kg) ≤ 2 Appendix A A.12 Loss on ignition, w /% ≤ 0.60 Appendix A A.13

Appendix A

(Normative) Testing method A.1 Warning Reagents of this standard test method for use in corrosive, the operator must be careful! Such as water splashed on the skin should immediately Flushing, severe cases should seek medical care immediately. When using flammable, do not use open flame heating. A.2 General Provisions The standard test methods used in the reagents and water, did not indicate when the other requirements, refer to analytically pure reagents and GB/T 6682-2008 Three water regulations. Used in the test standard titration solution, impurity standard solution, preparations and products, in the absence of other specified requirements, According to HG/T 3696.1, HG/T 3696.2, the provisions of HG/T 3696.3 of preparation. A.3 Identification Test A.3.1 Reagents and materials A.3.1.1 hydrochloric acid. A.3.1.2 ethanol. A.3.1.3 saturated solution of calcium hydroxide. Weigh 3 g of calcium hydroxide into 1000 mL of water, by vigorous stirring or shaking, place clarified supernatant take backup. A.3.1.4 magnesium sulfate solution. 120 g/L. A.3.1.5 ethanol solution of sodium tetraphenylborate. 34 g/L. A.3.1.6 red litmus paper. A.3.2 Analysis step A.3.2.1 Identification of carbonate A.3.2.1.1 take 50 mL 0.1 g/mL of test solution, placed in 250mL conical flask, a solution of hydrochloric acid, which release gases. This gas Introduced into a saturated solution of calcium hydroxide, white turbidity occurs. A.3.2.1.2 proper amount of 0.1 g/mL of test solution, a solution of magnesium sulfate solution, which occurred in a white precipitate. A.3.2.2 Identification of potassium ions A.3.2.2.1 proper amount of 0.1 g/mL of test solution was added sodium tetraphenylborate solution, that a large number of white precipitate formed. A.3.2.2.2 first to colorless combustion flame with hydrochloric acid in the colorless infiltration of platinum wire. Then dipped a little test solution, the colorless flame burning Burning, the flame was observed by cobalt glass purple. A.4 Determination of potassium carbonate A.4.1 potassium tetraphenylborate gravimetric method (Arbitration Act) A.4.1.1 Method summary In acid medium, potassium carbonate and sodium tetraphenylborate generate potassium tetraphenylborate precipitate. Depending on the quality Tetraphenylboron precipitated potassium chloride deduction, Potassium sulfate content was calculated mass of potassium carbonate. A.4.1.2 Reagents and materials A.4.1.2.1 ethanol. A.4.1.2.2 glacial acetic acid. 19. A.4.1.2.3 ethanol solution of sodium tetraphenylborate. 34 g/L. A.4.1.2.4 Tetraphenylboron ethanol saturated solution of potassium. A.4.1.2.5 methyl red indicator solution. 1 g/L. A.4.1.3 instruments and equipment A.4.1.3.1 sintered glass crucible. filter plate aperture 5μm ~ 15μm. A.4.1.3.2 electric oven. capable of controlling the temperature of 120 ℃ ~ 125 ℃. A.4.1.4 analysis step Weigh 0.8 g ~ 0.85 g calcined at 270 ℃ ~ 300 ℃ to constant mass of sample, to the nearest 0.0002 g, is dissolved in water and transferred to 500mL Volumetric flask, dilute to the mark, shake. If the test solution muddy, you need to dry filter, discard the initial 10 mL ~ 15 mL filtrate. With pipette 25 mL of the test solution was placed in 100 mL beaker, add 35 mL of water, 1 drop of methyl red indicator solution, with glacial acetic acid solution Raised to red, in a water bath heated to 40 ℃. Stirring was added dropwise 8.5 mL ethanol solution of sodium tetraphenylborate, placed 10 min to remove, Cool to room temperature. At 120 ℃ ~ 125 ℃ drying to constant quality glass sand filtration crucible with potassium tetraphenylborate saturated ethanol solution was transferred with Precipitated and washed with 15 mL each Tetraphenylboron saturated solution of potassium ethanol precipitated three times to four times with, drained. Remove the sand glass crucible with 2 mL Ethanol along the glass wall of the crucible sand wash, dry. Placed in the electric oven, at 120 ℃ ~ 125 ℃ dried to constant mass set. A.4.1.5 Calculation Results Potassium content of potassium carbonate (K2CO3) mass fraction w1 and its value is expressed in%, according to formula (A.1) Calculated. ()) 7931.09269.0 (050 025 1928.0 1 wwm mw - ×× = (A.1) Where. Numerical m1-- potassium tetraphenylborate precipitated mass in grams (g); m - mass of the sample value in units of grams (g); 0.192 8-- the conversion into potassium carbonate, potassium tetraphenylborate coefficient; w4-- determined in accordance with A.7 Chloride (KCl meter) mass fraction, expressed as a percentage; w5-- determined in accordance with A.8 sulfur compounds (in K2SO4 meter) mass fraction, expressed as a percentage; 0.926 9-- be converted to potassium chloride coefficient; Potassium carbonate, potassium sulfate 0.793 1-- The conversion factor is. Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.3%. A.4.2 acid-base titration A.4.2.1 Method summary Potassium carbonate in alkaline aqueous solution, titration with hydrochloric acid standard solution titration test solution, according to the consumption of hydrochloric acid standard solution titration, And deduct the amount of sodium carbonate, calcium carbonate, magnesium carbonate, and determine the amount of potassium carbonate. A.4.2.2 Reagents and materials A.4.2.2.1 hydrochloric acid standard titration solution. c (HCl) = 0.5 mol/L. A.4.2.2.2 Bromocresol green - methyl red mixed indicator solution. A.4.2.3 instruments and equipment High temperature furnace. the temperature can be controlled at 270 ℃ ~ 300 ℃. A.4.2.4 analysis step Weigh approximately 1 g at 270 ℃ ~ 300 ℃ ignition to constant mass of the sample to the nearest 0.0002 g. Placed in 250 mL conical flask, Add 50 mL of water to dissolve. Add 5 drops of Bromocresol green - methyl red mixed indicator solution, titration with hydrochloric acid standard titration solution until the solution turns from green dark red. The solution was boiled for 2 min, after cooling, continue titration to dark red. Make a blank test simultaneously. In addition to the blank test without the sample, but (except for standard titration solution) the type and amount of addition of reagents and other operations And determined in the same test. A.4.2.5 Calculation Results Potassium content of potassium carbonate (K2CO3) mass fraction w1 and its value is expressed in%, according to formula (A.2) Calculated. () [] ) 686.5006.3 (0 1 wwm cMVV w - × - = (A.2) Where. Numerical hydrochloric acid standard titration solution volume V-- titration solution consumed in milliliters (mL); Numerical hydrochloric acid standard titration solution volume V0-- titration blank test solution consumed in milliliters (mL); Accurate c-- hydrochloric acid standard titration solution concentration value in units of moles per liter (mol/L); Numerical m-- sample mass, expressed in grams (g); Numerical M-- potassium carbonate (1/2K2CO3) molar mass of the units of grams per mole (g/mol) (M = 69.10); w2-- A.5 measured according to the mass fraction of sodium content, expressed as a percentage; w3-- measured in accordance with A.6 Calcium, Magnesium (as Mg) content of the total, in%; 3.006-- sodium potassium carbonate in terms of coefficients; 5.686-- magnesium potassium carbonate conversion factor. Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.3%. A.5 Determination of sodium A.5.1 Reagents and materials A.5.1.1 potassium carbonate (spectroscopically pure) solution. 20 g/L. A.5.1.2 sodium standard solution. 1 mL solution of sodium (Na) 0.1 mg. Pipette Pipette 10 mL of sodium standard solution according to HG/T 3696.2 prepared, placed in 100 mL volumetric flask, dilute to the mark with water Degree, shake. A.5.2 Instruments and Equipment Flame spectrophotometer. A.5.3 Analysis step A.5.3.1 draw the curve In a series of 250 mL volumetric flask, each added 10 mL solution of potassium carbonate. Then were added 0.00 mL, 2.50 mL, 5.00 mL, 10.00 mL of standard solution of sodium. Diluted with water to the mark. Using a flame spectrophotometer, at a wavelength of 589 nm at the water transfer Zero, measuring the emission intensity. Sodium content as abscissa, after deduction of the reagent blank in order to launch corresponding intensity ordinate plotted curve. A.5.3.2 Determination It weighs about 0.2 g samples, accurate to 0.0002 g, placed in a beaker. Plus a small amount of water dissolved into 250 mL volumetric flask with water Dilute to the mark. Using a flame spectrophotometer, at a wavelength of 589 nm at zero water, measuring the emission intensity of the test solution. A.5.4 Calculation Results Sodium content of sodium (Na) mass fraction w2 and its value is expressed in%, according to formula (A.3) Calculated. () 01 2 × - × = wm mw (A.3) Where. Numerical quality test solution m1-- Richard from the working curve of sodium in milligrams (mg); m - the value of the sample mass, in grams (g); w8-- determined in accordance with A.13 loss on ignition, values expressed by%. Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.005%. A.6 Determination of calcium, magnesium, total A.6.1 Reagents and materials A.6.1.1 hydrochloric acid solution. 11. A.6.1.2 ammonia solution. 23. A.6.1.3 ammonia - ammonium chloride buffer solution A. pH≈10. A.6.1.4 Magnesium Standard solution. 1 mL solution containing magnesium (Mg) 1 mg. A.6.1.5 disodium edetate (EDTA) standard titration solution. c (EDTA) ≈0.05 mol/L. A.6.1.6 chrome black T indicator. A.6.2 Instruments and Equipment Microburette. Indexing is 0.02 mL. A.6.3 Analysis step Weigh about 5 g samples, accurate to 0.01 g, placed in 250mL conical flask, add 90 mL of water to dissolve, add hydrochloric acid solution and to pH≈4 (check with pH paper), heated to boiling 5 min, cooled. Pipette magnesium standard solution was added 5.00 mL, adjusted with ammonia pH≈8 (to pH paper test), added 5 mL ammonia - ammonium chloride buffer solution A, plus 0.1 g chrome black T indicator, shake. With EDTA Standard titration solution titration to the solution from purple to blue. Make a blank test simultaneously. In addition to the blank test without the sample, but (except for standard titration solution) the type and amount of addition of reagents and other operations And determined in the same test. A.6.4 Calculation Results Calcium and magnesium to the total mass of magnesium (Mg) fraction w3 and its value is expressed in%, according to formula (A.4) Calculated. () [] () 01 3 × - - = wm cMVV w (A.4) Where. Numerical EDTA standard titration solution volume V-- titration solution consumed in milliliters (mL); Numerical V0-- titration blank test solution consumed EDTA standard titration solution, in milliliters (mL); c - accurate EDTA standard titration solution concentration value in units of moles per liter (mol/L); Numerical m-- sample mass, expressed in grams (g); w8-- determined in accordance with A.13 loss on ignition, in%; Numerical M-- magnesium (Mg) molar mass in grams per mole (g/mol) (M = 24.31). Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.005%. Determination A.7 chloride A.7.1 potentiometric titration (Arbitration Act) A.7.1.1 Reagents and materials With GB/T 3050-2000 Chapter 4. A.7.1.2 instruments and equipment With GB/T 3050-2000 of Chapter 5. A.7.1.3 analysis step Weigh 1.9 g ~ 2.1 g samples, accurate to 0.01 g, placed in a 50 mL beaker, add a small amount of water wetting. 4 mL solution of nitric acid solution So that the liquid sample is dissolved, add 1 drop of bromophenol blue indicator, 71/92 solution of nitric acid to the test solution just yellow, combined with 15 mL 95% ethanol, The following standard silver nitrate titration solution [c (AgNO3) ≈0.005mol/L] according to GB/T 4.6 of the 3050-2000, from the "Add electric Magnetic stir bar, "to get started. At the same time a blank test. Blank test solution in a 50 mL beaker, was added 4 mL of nitric acid solution, the pH is adjusted to neutral with sodium hydroxide solution (with pH paper test), according to the measurement of "plus 1 drop of bromophenol blue indicator" Start with the test solution at the same time in the same manner. A.7.1.4 Calculation Results Chloride content of potassium chloride (KCl) mass fraction w4 and its value is expressed in%, according to formula (A.5) Calculated. () [] () 01 4 × - - = wm cMVV w (A.5) Where. Numerical standard silver nitrate titration solution volume V-- titration solution consumed in milliliters (mL); Numerical standard silver nitrate titration solution volume V0-- titration blank test solution consumed in milliliters (mL); c - accurate standard silver nitrate titration solution concentration value in units of moles per liter (mol/L); Numerical m-- sample mass, expressed in grams (g); w8-- determined in accordance with A.13 loss on ignition, in%; Numerical molar mass M-- potassium chloride (KCl), in units of grams per mole (g/mol) (M = 74.55). Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.003%. A.7.2 nephelometry A.7.2.1 Reagents and materials A.7.2.1.1 nitrate solution. 1 + l. A.7.2.1.2 Stabilizer. Amount of glycerol 200 mL, 200 mL of absolute ethanol was added 100 mL of water and mix thoroughly. A.7.2.1.3 KCl standard solution. 1 mL solution containing potassium chloride (KCl) 0.10 mg; Accurately weigh 0.1000 g calcined at 500 ℃ ~ 600 ℃ to constant mass of potassium chloride, dissolved in water, transferred to a 1000 mL capacity Bottle diluted with water to the mark. A.7.2.1.4 silver nitrate solution. 17 g/L. A.7.2.2 analysis step Weigh approximately 10 g samples, accurate to 0.01 g, dissolved in water, transferred to a 100 mL volumetric flask, dilute to the mark, shake, spare. Pipette Pipette l0 mL of test solution, placed in 100 mL beaker, add 10 mL of water. Was added dropwise a solution of 2 mL of nitric acid, After heated to boiling cooled and transferred to 50 mL colorimetric tube, add 1 mL solution of nitric acid, 10 mL stabilizers, 1 mL of silver nitrate solution, washed with water Dilute to the mark. Place 10 min, compared to a standard turbidity solution. Standard turbidity solution is in 50 mL colorimetric tube, add 0.00 mL, 0.50 mL, 1.00 mL, 1.50 mL, 2.00 mL, 2.50 mL standard potassium chloride solution, add 20 mL of water, following from the "plus 1 mL nitric acid solution" began, and at the same time with the test solution Sample processing. A.7.2.3 Calculation Results Chloride content of potassium chloride (KCl) mass fraction w4 and its value is expressed in%, according to formula (A.6) Calculated. () () 0100101 4 × - × = wm mw (A.6) Where. M1-- turbidity values and the test solution corresponding to the standard turbidity solution containing potassium chloride mass, in milligrams (mg); m-- sample mass value in grams (g); w8-- determined in accordance with A.13 loss on ignition in%. Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.005%. A.8 Determination of sulfur compounds A.8.1 Reagents and materials A.8.1.1 30% hydrogen peroxide. A.8.1.2 95% ethanol. A.8.1.3 hydrochloric acid solution. 1 + 11. A.8.1.4 barium chloride solution. 100 g/L. A.8.1.5 Potassium standard solution. 1 mL solution containing potassium sulfate (K2SO4) 0.10 mg; Accurately weighed 0.1000 g was dried to a constant mass of 105 ℃ ~ 110 ℃ anhydrous potassium sulphate (K2SO4), dissolved in water and transferred to 1000 mL Volumetric flask, dilute to the mark, shake. A.8.2 Analysis step Weigh approximately 10 g samples, accurate to 0.01 g, dissolved in water, transferred to a 100 mL volumetric flask, diluted with water to the mark. Pipette with a pipette 10.00 mL of test solution, placed in a 50 mL beaker, add 2 drops of 30% hydrogen peroxide, hydrochloric acid solution with 15 mL And heated to boiling for 2 min. After cooling, transferred to a 50 mL colorimetric tube, add 2 mL of hydrochloric acid solution, diluted with water to 40 mL, plus 5 mL95% ethanol, 3 mL of barium chloride solution, shake, holding 10 min at 30 ℃ ~ 35 ℃ water bath, diluted with water to the mark, shake, Compare with the standard turbidity solution. Standard turbidity solution is in four 50 mL colorimetric tube were added 0.00 mL, 0.50 mL, 1.00 mL, 1.50 mL of potassium standard solution. Add 10 mL each of water, 2 drops of 30% hydrogen peroxide, since the "add 2 mL of hydrochloric acid solution" simultaneously with the start of the test solution Kind of operation. A.8.3 Calculation Results Sulfur compound content to potassium sulfate (K2SO4) mass fraction w5 and its value is expressed in%, according to formula (A.7) calculated as follows. () () 0100101 5 × - × = wm mw (A.7) Where. M1-- turbidity values and the test solution corresponding to the standard turbidity solution containing potassium mass, in milligrams (mg); Numerical m-- sample mass, expressed in grams (g); w8-- determined in accordance with A.13 loss on ignition in%. Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.002%. A.9 Determination of iron A.9.1 Reagents and materials A.9.1.1 hydrochloric acid. A.9.1.2 ammonia solution. 11. The other with the GB/T 3049-2006 of Chapter 4. A.9.2 Instruments and Equipment Spectrophotometer. with 4 cm absorption cell. A.9.3 Analysis step A.9.3.1 draw the curve According to GB/T 3049-2006 6.3 stipulates that the choice of a thickness of 4 cm cuvettes and the appropriate standard iron solution, drawing working curve. A.9.3.2 Preparation of test solution Weigh about 2 g samples, accurate to 0.01g, placed 100 mL beaker, add 30 mL of water was dissolved, was added 4 mL of hydrochloric acid, add Hot boiled 3 min, cooled. A.9.3.3 Preparation of the blank test solution In the 100 mL beaker, 30 mL of water, 4 mL of hydrochloric acid, adjusting the pH to neutral with aqueous ammonia solution (with a pH test paper), Heat to boil 3 min, cooled. A.9.3.4 Determination The test solution and the blank test solution, according to GB/T 3049-2006 6.4 from the "add water to 60 mL" starts operation Make. Selection and the same curve measured absorption cell. A.9.4 Calculation Results Iron content of iron (Fe) mass fraction w6 and its value is expressed in%, according to formula (A.8) Calculated. () () 01 6 × - × - = wm mmw (A.8) Where. Numerical test solution iron quality m1-- isolated from the working curve, in milligrams (mg); Numerical blank test solution of iron quality m0-- isolated from the working curve, in milligrams (mg); m-- sample mass value in grams (g); w8-- determined in accordance with A.13 loss on ignition in%. Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.0005%. A.10 Determination of insoluble matter A.10.1 reagents and materials A.10.1.1 phenolphthalein indicator solution. 10 g/L. A.10.1.2 pickling Asbestos. Take appropriate acid asbestos immersed in hydrochloric acid solution (13) was boiled 20 min, and filtered on a Buchner funnel and washed with water until neutral. And then potassium carbonate solution (70 g/L) and soaked in boiling 20 min, filtered through a Buchner funnel and washed with water until neutral with water into a paste, spare. A.10.2 instruments and equipment A.10.2.1 Gooch crucible. 20 mL. A.10.2.2 electric oven. capable of controlling the temperature of 105 ℃ ± 2 ℃. A.10.3 Analysis steps A.10.3.1 prepare filter crucible The Gooch crucible filtration bottle placed on the sieve up and down the uniform layer of asbestos, each layer thickness of 3 mm, washed with distilled water until the filtrate Asbestos-free hair. The Gooch crucible moved into an oven electric thermostat, ± 2 ℃ after drying weighed in at 105 ℃. After the "distilled water The filtrate was free to wash cotton "repeat the operation until the constant Gooch crucible quality. The Gooch crucible means on the suction bottle with water wetting the asbestos layer and set aside. A.10.3.2 Determination Weigh approximately 20 g samples, accurate to 0.01 g. Placed 400 mL beaker, add 300 mL of water to dissolve. Quality has been used Constant Gooch crucible filtration. Insolubles were washed with distilled water, no significant red until the 20 mL washings add 2 drops of phenolphthalein after. The insolubles With Gooch crucible be dried to constant mass at 105 ℃ ± 2 ℃. A.10.4 Calculation Results Water-insoluble mass fraction w 7 and its value is expressed in%, according to formula (A.9) Calculated. () 018 twenty one 7 × - - = wm mmw (A.9) Where. Numerical m2-- Gooch crucible mass in grams (g); Numerical m1-- Gooch crucible and insolubles mass in grams (g); Numerical m-- sample mass, expressed in grams (g); w8-- determined in accordance with A.13 loss on ignition, values expressed by%. Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of absolute difference is not more than 0.005%. A.11 Determination of Heavy Metals (as Pb) of A tube. in 50 mL colorimetric tube, pipette 1.00 mL of lead standard solution [1 mL solution containing lead (Pb) 0.01 mg], add water to 25 mL. B and C tube pipe. each weighed 1.00 g ± 0.01 g sample was placed in 50 mL colorimetric tube, add 21 mL of water to dissolve. Dropping about 4 mL Hydrochloric acid solution (11), when the bubble does not occur until the solution, the tube with C pipetted into 1.00 mL of lead standard solution. The following press GB/T 5009.74-2003 Chapter 6 was measured. A.12 Determination of Arsenic Weigh 1.00 g ± 0.01 g sample was placed in a conical flask arsenic measuring device, add 25 mL of water to dissolve the sample. The solution of hydrochloric acid and To bubble solution (approximately 1.5 mL of hydrochloric acid) does not occur, then add 5 mL of hydrochloric acid, as the test solution. Limited preparation of standard solutions. pipette Pipette 2.00 mL of arsenic standard solution [1 mL solution of arsenic (As) 1.00 μmg], the following ...

Tips & Frequently Asked Questions:

Question 1: How long will the true-PDF of GB 25588-2010_English be delivered?

Answer: Upon your order, we will start to translate GB 25588-2010_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time.

Question 2: Can I share the purchased PDF of GB 25588-2010_English with my colleagues?

Answer: Yes. The purchased PDF of GB 25588-2010_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. 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+ countries

Question 4: Do you accept my currency other than USD?

Answer: Yes. If you need your currency to be printed on the invoice, please write an email to [email protected]. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.

Refund Policy     Privacy Policy     Terms of Service     Shipping Policy     Contact Information