GB 1903.16-2016National Food Safety Standard -- Food Nutrition Enhancer -- Ferric Pyrophosphate (English PDF)

2.1 Chemical name

Iron pyrophosphate

2.2 Molecular formula

Fe4 (P2O7) 3 · nH2O

2.3 Relative molecular mass

745.22 (anhydrous) (according to 2013 international relative atomic mass)

3.1 Sensory requirements

Sensory requirements shall comply with the requirements of Table 1.

Table 1 sensory requirements

The project requires a test method Color yellowish white to tan State powder Odor smells are irony Take appropriate sample on a clean, dry white porcelain dish or beaker in the natural light to observe the color and state, smell it odor

3.2 Physical and chemical indicators

Physical and chemical indicators should be consistent with the provisions of Table 2.

Table 2 Physical and chemical indicators

Item Index Test Method Iron content (Fe), w /% 24.0 ~ 26.0 Appendix A A.4 Burning reduction, w /% <= 20.0 Appendix A A.5 Lead (Pb)/(mg/kg) <= 4.0 Appendix A A.6

Table 2 (continued)

Item Index Test Method Arsenic (As)/(mg/kg) <= 3.0 Appendix A A.7 Total Mercury (in Hg)/(mg/kg) <= 3.0 Appendix A A.8 Chloride (in Cl), w /% <= 3.55 Appendix A, A.9 Sulfate (calculated as SO4) a, w /% <= 0.12 A. A in Appendix A.

a sulfate is only applicable to sodium pyrophosphate, ferric chloride as raw material for the production of products.

Appendix A

Testing method

A.1 Safety Tips

Some of the reagents used in this standard test procedure are toxic or corrosive and should be handled with care. Such as splashing on the skin, should be immediately Rinse with water, severe should be treated immediately. When using volatile acids, it is necessary to carry out in the fume hood.

A.2 General provisions the reagents and water used in this standard refer to the pure reagent and the tertiary water specified in GB/T 6682 when no other requirements are specified. this Standard test, the standard solution, impurity standard solution, preparation and products, in the absence of other requirements are GB/T 601, GB/T 602, GB/T 603. The solution used in this test does not specify what kind of solvent preparation, refers to the aqueous solution.

A.3 Identification test A.3.1 Reagents and materials A.3.1.1 hydrochloric acid solution. 1 1.

A.3.1.2 Hydrochloric acid solution. 0.1 mol/L.

A.3.1.3 Sodium hydroxide solution. 1 mol/L.

A.3.1.4 bromophenol blue solution. Weigh 100mg bromophenol blue, dissolved in 100mL ethanol (12), if necessary, filtration.

A.3.1.5 Zinc Sulfate Solution. 125 g/L.

A.3.2 Instruments and equipment Acidity meter. Accuracy of pH ± 0.01.

A.3.3 Analysis steps A.3.3.1 Iron ion identification Weigh 0.50g sample, placed in 100mL beaker, add 5mL hydrochloric acid solution (1 1) dissolved sample, add excess 1mol/L hydrogen Sodium solution, should produce reddish brown precipitate.

A.3.3.2 Identification of pyrophosphate ions Place the A.3.3.1 test solution for several minutes and filter, discard the first few liters of the filtrate, add 1 drop of bromophenol in 5 mL of clear filtrate Blue solution, with 0.1mol/L hydrochloric acid solution titrated to green. Add 10mL zinc sulfate solution, with 0.1mol/L hydrochloric acid solution to adjust the pH the whole to 3.8, should produce white precipitate.

A.4 Determination of iron content (Fe) A.4.1 Method 1 Potassium dichromate method A.4.1.1 Method Summary the sample was dissolved in hydrochloric acid solution, reduced with stannous chloride, oxidized to excess stannous chloride with mercuric chloride, indicated by sodium diphenylamine sulfonate and titrated with a standard solution of potassium dichromate to determine the iron content in the sample.

A.4.1.2 Reagents and materials A.4.1.2.1 Hydrochloric acid solution. 1 2.

A.4.1.2.2 Stannous chloride solution. 40 g of stannous chloride (SnCl2 · 2H2O) was weighed into 100 mL of concentrated hydrochloric acid.

A.4.1.2.3 Sulfuric acid-phosphoric acid solution. 75 mL of concentrated sulfuric acid was slowly added to 300 mL of water, cooled, 75 mL of phosphoric acid was added, Capacity to 500mL.

A.4.1.2.4 Mercury chloride saturated solution. Weigh 64 g of mercuric chloride and dissolve in 986 mL of water.

A.4.1.2.5 Sodium diphenylamine sulfonate solution. 300mg of diphenylamine sulfonate was weighed and dissolved in 100mL water.

A.4.1.2.6 Potassium Dichromate Standard titration solution. c 16K2Cr2O7 ÷ = 0.1mol/L.

Note. Mercury chloride is highly toxic A.4.1.3 Analysis steps Accurately weighed the sample 3.5g (accurate to 0.0001g), set 250mL beaker, add 75mL hydrochloric acid solution (1 2) dissolved sample, add Heat to boiling, about 5min. Cooling into the 100mL volumetric flask, with hydrochloric acid solution (1 2) constant volume, mix, the amount of the solution to take 25mL, Into a 500mL Erlenmeyer flask, add 100mL hydrochloric acid solution (12), then boil for 5min, stirring while stirring stannous chloride solution until Yellow disappears (iron is just to restore). An excess of 2 drops of stannous chloride solution was added, diluted with 50 mL of water and cooled to room temperature. In the sharp mixing Add 15mL mercuric chloride saturated solution, placed 5min after adding 15mL sulfuric acid - phosphoric acid solution. Shake, add 0.5mL diphenylamine Sodium sulfonate solution, titrated with 0.1mol/L potassium dichromate standard titration solution to red purple.

At the same time as the measurement, the same amount of reagent solution was used as a blank test in the same procedure as in the measurement.

A.4.1.4 Calculation of results the mass fraction w1 of iron content (Fe) is calculated according to formula (A.1) w1 = c × (V1 - V0) × M × 4 m × 1000 × 100% (A.1) where.

c - the actual concentration of potassium dichromate standard titration solution in moles per liter (mol/L);

V1 --- sample consumption of potassium dichromate standard titration solution volume, in milliliters (mL);

V0 --- blank test consumption of potassium dichromate standard titration solution volume, in milliliters (mL);

M - the molar mass of iron in grams per mole (g/mol) [M (Fe) = 55.85 g/mol];

4 --- dilution factor;

m --- the quality of the sample, in grams (g);

1000 --- conversion factor.

The results of the test are based on the arithmetic mean of the parallel measurement results. The absolute difference between the two independent determinations obtained under repeatability conditions Value is not greater than 0.2%.

A.4.2 Second method iodometric method A.4.2.1 Methodological Summary in the acidic medium, the trivalent iron in the sample reacts with potassium iodide to produce free iodine, titrated with sodium thiosulfate standard titration solution Calculate the iron content in the sample.

A.4.2.2 Reagents and materials A.4.2.2.1 Hydrochloric acid solution. 1 2.

A.4.2.2.2 Potassium iodide.

A.4.2.2.3 sodium thiosulfate standard titration solution. c (Na2S2O3) = 0.1mol/L.

A.4.2.2.4 Starch Indication Solution. 5 g/L.

A.4.2.3 Analysis steps Weigh about 3.5g sample (accurate to 0.0001g), set 250mL beaker, add 75mL hydrochloric acid solution (1 2) dissolved sample, add Heat to boiling, about 5min. Cooled into the 100mL volumetric flask, with hydrochloric acid solution (1 2) constant volume, mix, the amount of the solution 15mL in the iodine bottle, add 3g potassium iodide, placed in the dark for 5min. Titration with sodium thiosulfate standard titration solution, to light yellow, add 0.3mL Starch indicator solution, continue to titrate until the blue disappears as the end point.

At the same time as the measurement, the same amount of reagent solution was used as a blank test in the same procedure as in the measurement.

A.4.2.4 Calculation of results the mass fraction w2 of iron content (Fe) is calculated according to formula (A.2) w2 = c × (V1 - V0) × M m × 100 × 1000 × 100% (A.2) where.

c - the actual concentration of sodium thiosulfate standard titration solution in moles per liter (mol/L);

V1 --- sample consumption of sodium thiosulfate standard titration solution volume, in milliliters (mL);

V0 --- blank test consumption of sodium thiosulfate standard titration solution volume, in milliliters (mL);

M - the molar mass of iron in grams per mole (g/mol) [M (Fe) = 55.85 g/mol];

m --- the quality of the sample, in grams (g);

15 --- Measure the volume of the sample solution in milliliters (mL);

100 --- capacity of the capacity of the bottle, in milliliters (mL).

The results of the test are based on the arithmetic mean of the parallel measurement results. The absolute difference between the two independent determinations obtained under repeatability conditions Value is not greater than 0.2%.

A.5 Determination of burning reduction A.5.1 Instruments and equipment High temperature furnace. Controlled temperature 800 °C ± 25 °C.

A.5.2 Analysis steps Approximately 1 g of the sample (accurate to 0.0001 g) was weighed and placed in a porcelain crucible which was preheated at 800 ° C ± 25 ° C until mass 800 °C ± 25 °C high temperature furnace burning 1h. Into the dryer to cool to room temperature, weighing. Repeated burning to the front and rear weighing difference between the two do not More than 0.5mg is constant weight.

A.5.3 Calculation of results the mass fraction w3 of the burn reduction is calculated according to equation (A.3) w3 = m-m1 m x 100% (A.3) where.

m --- the quality of the sample, in grams (g);

m1 - the mass of the sample after ignition, in grams (g).

The results of the test are based on the arithmetic mean of the parallel measurement results. The absolute difference between the two parallel determinations is not more than 0.2%.

A.6 Determination of lead (Pb) A.6.1 Methodological summary After the sample was treated, the lead was extracted by trioctylphosphine oxide-methyl isobutyl ketone solution, and the sample solution was introduced into the atomic absorption spectrophotometry Photometer, the flame atomization, the absorption of 283.3nm resonance line, the absorption and lead content is proportional to.

A.6.2 Reagents and materials A.6.2.1 Hydrochloric acid solution. 3 1.

A.6.2.2 Ascorbic acid solution. 100 mg/mL.

A.6.2.3 Sodium iodide solution. 192.5 mg/mL.

A.6.2.4 ascorbic acid - sodium iodide solution. measure 100mL ascorbic acid solution and 100mL sodium iodide solution, mix well.

A.6.2.5 Trioctylphosphine oxide-methyl isobutyl ketone solution. Weigh 5.00g trioctylphosphine oxide, dissolved with methyl isobutyl ketone, 100 mL to prepare a 50 mg/mL trioctylphosphine oxide-methyl isobutyl ketone solution.

A.6.2.6 lead standard stock solution. accurately weighed 1.000g metal lead (99.99%), graded with a small amount of nitric acid, dissolved by heating, into the 1000mL capacity Measuring bottle, add water to constant volume. Mix, this solution contains 1.0 mg of lead per milliliter.

A.6.2.7 Lead Work Standard Solution. Remove 1 mL of standard stock solution to 1000 mL volumetric flask, dilute to the mark with water, shake. Remove 2mL the solution was poured into a 50 mL volumetric flask, 10 mL of hydrochloric acid solution (31), 10 mL of water, 20 mL of ascorbate-sodium iodide solution, 5 mL Trioctylphosphine oxide - methyl isobutyl ketone solution, repeated shaking. Add water to the organic solvent layer to the bottleneck, shake, standing stratified. Organic solvents Layer is the standard working solution, the solution containing 0.4µg per ml of lead.

A.6.2.8 Blank solution. Remove 10 mL of hydrochloric acid solution (3 1), add 10 mL of water, 20 mL of ascorbate-sodium iodide solution, 5 mL of tris Octylphosphine oxide - methyl isobutyl ketone solution to a 50 mL volumetric flask, repeatedly shaken. Add water to the organic solvent layer to the neck, shake, standing Layered. The organic solvent layer is a blank solution.

A.6.3 Instruments and equipment Atomic Absorption Spectrophotometer. With lead hollow cathode lamp.

A.6.4 Analysis steps A.6.4.1 Preparation of sample solution Weigh 0.50g sample (accurate to 0.01g) to 50mL volumetric flask, add 10mL hydrochloric acid solution (3 1) to dissolve, add 10 mL of water, 20 mL of ascorbate-sodium iodide solution, 5 mL of trioctylphosphine oxide-methyl isobutyl ketone solution and shake well. Add water to make organic solution Layer to the bottleneck, shake, static stratification. The organic solvent layer is the sample solution.

A.6.4.2 Determination the sample solution was introduced into an atomic absorption spectrophotometer, and after the flame atomization, the 283.3nm resonance line was absorbed, and the mixture was treated with trioctylphosphine oxide the base isobutyl ketone solution is zeroed, and the absorbance of the blank solution, the standard working solution and the sample solution is sequentially detected. The absorbance of the sample solution the degree of absorbance should not be greater than the standard solution.

A.7 Determination of arsenic (As) Weigh 0.5g sample (accurate to 0.01g), add 5mL concentrated hydrochloric acid dissolved, adding thiourea - ascorbic acid solution (weighed 50g thiourea, 50g ascorbic acid, dissolved in water, constant volume to 100mL) 1mL, constant volume to 10mL, as the sample solution. The following according to GB 5009.11-2014 "The first determination of total arsenic," the provisions of the second law.

A.8 Determination of total mercury (in Hg) Weigh 0.5g sample (accurate to 0.01g), add 5mL concentrated hydrochloric acid dissolved, set to 10mL, as the sample solution. Press the following GB 5009.17-2014 "Determination of total mercury in the first food" in the first law of the provisions of the determination.

A.9 Determination of chloride (in terms of Cl) A.9.1 Reagents and materials A.9.1.1 Nitric acid solution. 1 1.

A.9.1.2 Nitric acid solution. 1 9.

A.9.1.3 Phenolphthalein indicator. 10 g/L.

A.9.1.4 Sodium hydroxide solution. 3 mol/L.

A.9.1.5 Silver nitrate solution. 20 g/L.

A.9.1.6 Chloride standard solution. 3.55 g/L. When used, the standard solution is diluted 10 times, so that the chloride (in Cl) mass concentration 0.355g/L.

A.9.2 Analysis steps Weigh this product 1.0g (accurate to 0.01g), set 100mL beaker, add 15mL nitric acid solution (1 1) in the water bath by heating solution. To this solution was added a few drops of phenolphthalein indicator and sodium hydroxide solution 50mL, fully mixed, transferred to 100mL volumetric flask, dilute Release to the mark, place 10min, filter with dry filter paper. Take the filtrate 10mL, transfer to 100mL volumetric flask, dilute to the mark, as Test solution.

The test solution (2.0 mL) was neutralized in a 50 mL colorimetric tube with nitric acid solution (19), and 1.0 mL of silver nitrate solution was diluted.

To the scale, fully mixed, dark place for 5min, the two color tube placed on a black background, from the side or above observation, test solution was Turbidity should not be greater than the standard tube.

Standard tube preparation. 0.355g/L chloride standard solution 0.20mL, with the same test solution at the same time.

A.10 Sulfate (measured in SO4) A.10.1 Reagents and materials A.10.1.1 Concentrated hydrochloric acid.

A.10.1.2 Sulfate (in SO4) Standard solution. 0.48 g/L.

A.10.1.3 Barium chloride solution. 120 g/L.

A.10.2 Analysis steps A 40.2 of the filtrate was taken in 50 mL of a colorimetric tube, neutralized with concentrated hydrochloric acid and excessed in an amount of 1 mL to 2 mL, and 2 mL Barium chloride solution, fully mixed, diluted with water to the mark, placed 10min, the two color tube placed on a black background, from the side or above the turbidity of the test solution shall not be greater than that of the standard tube.

Standard tube preparation. take 0.48g/L sulfate standard solution 1.00mL, with the same test solution at the same time.