GB 1886.216-2016National Food Safety Standard -- Food Additives -- Magnesium oxide (including heavy and light) (English PDF)

2.1 Molecular formula

MgO

2.2 Relative molecular mass

40.30 (according to 2013 International Relative Atomic Quality)

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 white State powder Take the appropriate amount of sample in a 50mL beaker and look under natural light Color and state

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 Magnesium oxide (MgO, after burning) content, w /% 96.0 ~ 100.5 Appendix A, A.4 Calcium oxide (CaO), w /% <= 1.5 Appendix A A.5 Acid insoluble matter, w /% <= 0.1 Appendix A A.6 Burning reduction, w /% <= 5.0 Appendix A A.7 the free base was tested in Appendix A, A.8

Table 2 (continued)

Item Index Test Method Soluble salts were tested in Appendix A, A.9 Arsenic (As)/(mg/kg) <= 3.0 GB 5009.76 Lead (Pb)/(mg/kg) <= 4.0 GB 5009.12 or GB 5009.75 Appendix A Testing method A.1 Warning Some of the reagents used in this test method are corrosive and the operator should be careful to rinse on the skin immediately with water Severe cases should be treated immediately.

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. test the standard titration solution, preparation and products used in the test shall be prepared according to the provisions of GB/T 601 and GB/T 603 when no other requirements are specified.

The solution used refers to an aqueous solution when it is not specified with any solvent formulation.

A.3 Identification test A.3.1 Reagents and materials A.3.1.1 Ammonium chloride.

A.3.1.2 Hydrochloric acid solution. 1 3.

A.3.1.3 Ammonia solution. 2 3.

A.3.1.4 Ammonium carbonate solution..200 g/L. Weigh 20.0 g of ammonium carbonate, dissolve in water, add 20 mL of ammonia, and dilute to 100 mL with water.

A.3.1.5 Sodium phosphate solution. 60 g/L.

A.3.2 Identification method Weigh about 1g sample, dissolved in 25mL hydrochloric acid solution, in the presence of ammonium chloride, the sample solution and the addition of ammonium carbonate solution is not to form a precipitate, continue to add sodium phosphate solution, the formation of insoluble ammonia solution of white crystalline precipitate.

Determination of the content of magnesium oxide (MgO, after burning) A.4.1 Methodological Summary with triethanolamine mask a small amount of trivalent iron, trivalent aluminum and divalent manganese ions, at pH 10, with chromium black T as an indicator, with B Ammonium tetraacetate disodium standard titration solution titration, calculate the amount of calcium and magnesium, from which to reduce the calcium content of magnesium oxide content.

A.4.2 Reagents and materials A.4.2.1 Hydrochloric acid solution. 1 1.

A.4.2.2 Ammonia solution. 1 1.

A.4.2.3 Triethanolamine solution. 1 3.

A.4.2.4 Ammonia - Ammonium chloride buffer solution A (pH ~ 10).

A.4.2.5 Disodium ethylenediamine tetraacetate (EDTA) standard titration solution. c (EDTA) = 0.02 mol/L.

A.4.2.6 Chromium Black T Indicator.

A.4.3 Analysis steps Weigh about 5g sample, accurate to 0.0002g, placed in 250mL beaker, with a small amount of water wetting, adding about 55mL hydrochloric acid solution, Stir until the sample is completely dissolved. Cover the surface dish, boil 3min ~ 5min, after cooling into the 500mL volumetric flask, diluted with water Degree, shake well. This is the sample solution A, for the magnesium oxide content, the determination of calcium oxide content.

Pipette 25mL sample solution A, placed in a 250mL volumetric flask, diluted with water to the mark, shake. Remove from pipette 25mL of the sample solution, placed in 250mL Erlenmeyer flask, add 50mL of water, with ammonia solution to adjust the solution to pH7 ~ 8 (with a wide pH Test paper), add 5mL triethanolamine solution, 10mL ammonia - ammonium chloride buffer solution, 0.1g chromium black T indicator, with ethylenediamine Disodium tetraacetic acid (EDTA) standard titration solution titrated to the solution from purple to pure blue for the end.

A.4.4 Calculation of results the mass fraction w1 of magnesium oxide (MgO, after burning) is calculated according to formula (A.1) w1 = (V1-V2 ) × c × M1 m1 × 500 × 250 × 1000 × 100% (A.1) where.

V1 --- titration of the sample solution consumed by ethylenediamine tetraacetic acid disodium (EDTA) standard titration solution volume in milliliters (mL);

V2 - A.5.2.5 titration of calcium oxide consumed by the disodium ethylenediamine tetraacetate (EDTA) standard titration solution volume, unit in milliliter (mL);

20 --- conversion factor;

c - the concentration of ethylenediamine tetraacetic acid disodium (EDTA) standard titration solution in moles per liter (mol/L);

M1 - the molar mass of magnesium oxide in grams per mole (g/mol) [M (MgO) = 40.30];

m1 --- the quality of the sample, in grams (g);

25 --- Remove the volume of sample solution A in milliliters (mL);

500 --- volume of the volumetric flask, in milliliters (mL);

25 --- Remove the volume of the sample solution in milliliters (mL);

250 --- volume of the volumetric flask, in milliliters (mL);

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%.

Determination of Calcium Oxide (CaO) A.5.1 Methodological Summary with triethanolamine to mask a small amount of trivalent iron, trivalent aluminum and divalent manganese ions, at pH 12.5, with calcium reagent sodium carboxylate as an indicator Agent, with ethylenediamine tetraacetic acid disodium standard titration solution titration of calcium ions.

A.5.2 Reagents and materials A.5.2.1 Sodium hydroxide solution. 100 g/L.

A.5.2.2 Triethanolamine solution. 1 3.

A.5.2.3 Disodium Triethylenediamine Tetraacetate (EDTA) Standard titration solution. c (EDTA) = 0.02 mol/L.

A.5.2.4 calcium reagent carboxylic acid sodium salt indicator. Weigh 10g at 105 °C ± 5 °C for 2h drying sodium chloride, placed in a mortar, add 0.1g Calcium Reagent Carboxylic acid sodium salt fine, mix well. Placed in a weighing bottle, stored in a dryer. The use period is two months.

A.5.2.5 Analysis steps Remove 50 mL of sample solution A (A.4.3) with a pipette and place in a 250 mL Erlenmeyer flask. Add 30 mL of water, 5 mL of triethanolamine Solution, shake the drop of sodium hydroxide solution, when the solution just precipitated, add 0.1g calcium reagent sodium carboxylate indicator, continue to drop hydrogen Sodium oxide solution to solution from blue to wine red, and excess 0.5mL. Titration of the solution with ethylenediamine tetraacetic acid disodium (EDTA) standard Set the solution from wine red to pure blue for the end.

A.5.3 Calculation of results Calcium oxide (CaO) content of the mass fraction w2, according to formula (A.2) calculation.

V2 × c × M2

500 × 1000

× 100% (A.2)

Where.

V2 - titration of the volume of the standard titration solution of disodium EDTA (EDTA) consumed in the sample solution in milliliters (mL);

c - the concentration of ethylenediamine tetraacetic acid disodium (EDTA) standard titration solution in moles per liter (mol/L);

M2 - molar mass of calcium oxide in grams per mole (g/mol) [M (CaO) = 56.08];

m1 --- A.4.3 the quality of the sample, in grams (g);

50 --- Remove the volume of sample A, in milliliters (mL);

500 --- volume of the volumetric flask, in milliliters (mL);

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 the value is not greater than 0.1%.

A.6 Determination of acid insoluble matter A.6.1 Reagents and materials A.6.1.1 hydrochloric acid solution. 1 1.

A.6.1.2 Silver nitrate solution. 17 g/L.

A.6.2 Instruments and equipment A.6.2.1 porcelain crucible. 30mL.

A.6.2.2 High temperature furnace. temperature can be controlled at 875 °C ± 25 °C.

A.6.3 Analysis steps Weigh about 2g of sample, accurate to 0.0002g. Placed in a beaker, add 75mL of water, stir. Add about 20 mL of hydrochloric acid solution in divided portions Liquid to the sample is no longer dissolved, boil 5min, hot with medium speed quantitative filter paper filter, washed with hot water to the filtrate without chloride ions (with silver nitrate solution), The filter paper and the insoluble material were placed in advance at 875 ° C ± 25 ° C burning to a constant quality porcelain crucible, dried, 875 °C ± 25 °C in the high temperature furnace burning to a constant quality.

A.6.4 Calculation of results the mass fraction w3 of the acid insoluble matter is calculated according to the formula (A.3) w3 = m2 m3 × 100% (A.3) where.

m2 - the mass of the residue after ignition, in grams (g);

m3 --- the quality of the sample, 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 independent determinations obtained under repeatability conditions the value is not more than 0.02%.

A.7 Determination of burning reduction A.7.1 Instruments and equipment A.7.1.1 porcelain crucible. 30mL.

A.7.1.2 High temperature furnace. temperature can be controlled at 875 °C ± 25 °C.

A.7.2 Analysis steps Weigh about 0.5g of sample, accurate to 0.0002g. Placed in advance at 875 °C ± 25 °C burning to the quality of the porcelain crucible, placed 875 °C ± 25 °C in the high temperature furnace burning to a constant quality.

A.7.3 Calculation of results the mass fraction w4 of the burn reduction is calculated according to equation (A.4) w4 = m4-m5 m4 × 100% (A.4) where.

m4 --- the quality of the sample, in grams (g);

m5 --- the quality of the sample after burning, 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 independent determinations obtained under repeatability conditions Value is not greater than 0.2%.

A.8 Determination of free base A.8.1 Reagents and materials A.8.1.1 Sulfuric acid standard titration solution. c ( 2H2SO4 ) = 0.100 mol/L.

A.8.1.2 methyl red indicator solution. 1g/L.

A.8.2 Analysis steps 2.00 g ± 0.01 g sample was weighed and placed in a beaker. Add 100 mL of water, cover the surface dish and boil for 5 min. Hot in the speed of the set Filter the filter, the filtrate collected in 100mL volumetric flask, after cooling diluted with water to the mark, shake. This is sample solution B, for free Determination of alkali and soluble salts.

Remove the 50 mL sample solution B from the pipette, place it in a conical flask, add 2 drops of methyl red indicator solution, titrate the solution drop with sulfuric acid Set the solution to red. Sulfuric acid standard titration solution consumption is not greater than 2.0mL, that is, through the test.

A.9 Determination of soluble salts A.9.1 Instruments and equipment A.9.1.1 electric thermostat oven. temperature can be controlled to 105 °C ± 2 °C.

A.9.1.2 constant temperature water bath.

A.9.2 Analysis steps 25 mL of Sample Solution B (A.8.2) was removed from the pipette at 105 ° C ± 2 ° C to a constant evaporating dish.

Constant temperature water bath evaporated to dry. The pan was dried in an electrothermal oven at 105 ° C ± 2 ° C for 1 h. Remove, cool, weigh.

The amount of residue is not greater than 10mg, that is through the test.