GB 25590-2010National food safety standards of food additives sodium bisulfite (English PDF)

Foreword

Appendix A of this standard is a normative appendix.

National Food Safety Standard Food Additives Sodium bisulfite

1 Scope

This standard applies to industrial food additive sodium absorption of sodium bisulfite to produce the sulfur dioxide produced.

2 Normative references

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

3 Formula and relative molecular mass

Formula 3.1

NaHSO3

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 granules state organization

4.2 Physical indicators. to comply with Table 2.

Table 2. Physical and chemical indicators

Item Index Test Method Main content (SO2 meter), w /% 58.5 ~ 67.4 Appendix A A.4 Water-insoluble, w /% <= 0.01 Appendix A A.5 Iron (Fe)/(mg/kg) <= 50 Appendix A A.6 Arsenic (As)/(mg/kg) <= 2 Appendix A A.7 Heavy metals (Pb)/(mg/kg) <= 5 Appendix A A.8 Lead (Pb)/(mg/kg) <= 2 Appendix A A.9 Selenium (Se)/(mg/kg) <= 5 Appendix A A.10 Appendix A (Normative) Testing method A.1 Warning Reagents The standard test methods used for toxic or corrosive, the operator must be careful! Should immediately splashed on the skin, such as Rinse water, severe cases should be treated 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 in Three water regulations. Used in the test standard titration solution, impurity standard solution, preparations and products, did not indicate when the other requirements, according to HG/T 3696.1, HG/T 3696.2, the provisions prepared HG/T 3696.3 of.

A.3 Identification Test A.3.1 Reagents and materials A.3.1.1 hydrochloric acid.

A.3.1.2 hydrochloric acid solution. 13.

A.3.1.3 potassium iodide solution. 360 g/L.

A.3.1.4 iodine solution. take 1.4 g iodine, placed in 10 mL of potassium iodide solution, add two drops of hydrochloric acid, dissolved in water and diluted to 100 mL, storage in brown bottle stored.

A.3.1.5 mercury nitrate solution. take 15 g of mercury nitrate Asia, add 90 mL of water, 10 mL solution of nitric acid (19) was dissolved, add a drop of mercury, dark Sealed and stored for later use.

A.3.2 Analysis step

A.3.2.1 Identification sulfite After the sample solution was added iodine solution that is faded yellow.

Aqueous hydrochloric acid solution was dropped after the sample has a sulfur dioxide gas to escape to Asia mercury nitrate solution infiltrating dipstick test, which was black.

A.3.2.2 Identification of sodium ions Infiltration of platinum wire with hydrochloric acid to colorless in the first combustion colorless flame. Then dipped a little sample solution in a colorless flame combustion, the flame that was Bright yellow.

A.4 Determination of the main content (SO2 basis) A.4.1 Method summary in weakly acidic solution with iodine sulfite oxidized to sulfate. Starch as indicator, titrated with sodium thiosulfate standard solution titration Excess iodine.

A.4.2 Reagents and materials A.4.2.1 acetic acid solution. 13.

A.4.2.2 iodine standard solution. c (1/2I2) = 0.1mol/L.

A.4.2.3 sodium thiosulfate standard titration solution. c (Na2S2O3) = 0.1mol/L.

A.4.2.4 starch indicator solution. 5g/L.

A.4.3 Analysis step

It weighs about 0.2g sample quickly and accurately to 0.000 2g. Previously placed with a pipette 50mL was added iodine standard solution and 30mL ~ 50mL Water 250mL iodine bottle, add 5mL of acetic acid solution, and immediately cover the cork, seal, after shaking slowly dissolved into a dark place 5min.

Titration with sodium thiosulfate standard solution titration, adding about 3mL starch indicator solution near the end, continue titration to the disappearance of the blue is the end. with when the blank test.

In addition to the blank test without the sample, the addition of reagents and other operations of the kind and amount (other than the standard titration solution) with the same measurement sample.

A.4.4 Calculation Results Main content of sulfur dioxide (SO2) mass fraction w1 and its value is expressed in%, according to formula (A.1) Calculated.

] 1000 /) [(10

cMVV

w (A.1)

Where.

Numerical sodium thiosulfate standard titration V0-- titration blank test solution consumed by the solution volume in milliliters (mL);

Numerical sodium thiosulfate standard titration solution consumed V1-- titration solution volume in milliliters (mL);

Accurate c-- sodium thiosulfate standard titration solution concentration value in units of moles per liter (mol/L);

m-- sample mass value in grams (g);

Numerical M-- dioxide (1/2SO2) molar mass in grams per mole (g/mol) (M = 32.03).

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 0.2%.

A.5 Determination of insoluble matter A.5.1 Instruments and Equipment A.5.1.1 sintered glass crucible. filter plate aperture 5µm ~ 15µm.

A.5.1.2 electric oven. the temperature can be controlled at 105 °C ± 2 °C.

A.5.2 Analysis step

It weighs about 20g sample to the nearest 0.01g. Placed in 400mL beaker with about 100mL water dissolve. Use was 105 °C ± 2 °C drying to quality A constant amount of glass sand filtration crucible, the residue was washed with water, 60 °C ~ 80 °C 4 to 5 times, each time with about 30mL of water. The glass sand crucible and residues Slag at 105 °C ± 2 °C dried to constant mass.

A.5.3 Calculation Results Water-insoluble mass fraction w2 and its value is expressed in%, according to formula (A.2) Calculated.

0122 × - = m

mmw (A.2)

Where.

Numerical m1-- sintered glass crucible mass in grams (g);

Numerical m2-- water insoluble sand and glass crucible mass in grams (g);

m-- sample mass value in grams (g).

Take the arithmetic mean of the parallel determination results of the measurement results. Two parallel determination results of absolute difference is not more than 0.005%.

A.6 Determination of iron A.6.1 Reagents and materials with GB/T 3049-2006 Chapter 4.

A.6.2 Instruments and Equipment with GB/T 3049-2006 of Chapter 5.

A.6.3 Analysis step

A.6.3.1 draw the curve GB T 3049-2006 according to the provisions of 6.3/absorption cell using optical path 4cm 5cm and the corresponding amount of iron standard solution or drawn work curve.

A.6.3.2 Preparation of test solution Weigh about 5g sample to the nearest 0.01g. 250mL beaker and placed on a high type, with a small amount of water dissolved, 25mL hydrochloric acid solution in a boiling water bath Evaporated to dryness. The residue was dissolved in water, all transferred to 100mL volumetric flask, dilute with water to the mark.

A.6.3.3 Preparation of the blank test solution High type in 250mL beaker, add a small amount of water, plus 25mL of hydrochloric acid in a boiling water bath to dryness, the residue was dissolved in water, cooled all Transferred to 100mL volumetric flask.

A.6.3.4 Determination Test solution and the blank test solution, respectively, according to GB/T 3049-2006 6.4 from the "if necessary, add water to 60mL" to get started.

In addition to the blank test without the sample, the type and amount of addition of reagents and other operating and measured in the same sample.

A.6.4 Calculation Results Iron content of iron (Fe) mass fraction w3 and its value in mg/kg according to formula (A.3) Calculated.

twenty one

3 10- ×

mmw (A.3)

Where.

Numerical test solution iron quality m1-- from the working curve of Richard, in milligrams (mg);

Numerical blank test solution of iron in quality from the working curve m2-- Richard, in units of milligrams (mg);

m - mass of the sample value in units of grams (g).

Take the arithmetic mean of the parallel determination results of the measurement results. Two parallel determination results of absolute difference is not more than 1mg/kg.

A.7 Determination of Arsenic Weigh 1g sample accurate to 0.01g, for diethyl dithiocarbamate silver colorimetry, or weighed 1.00g ± 0.01g sample, with in Gutzeit method. Sample is placed in a conical flask, wetted with water, neutralized with hydrochloric acid to neutral (pH paper test with), and then excess 5mL, shake uniform. Pipette 2.00mL arsenic standard solution [1mL solution containing 1.0µg arsenic (As)] as a standard, placed in another conical flask. Each added 5mL Hydrochloric acid solution (13). And then follow the GB/T 5009.76-2003 6.2 or Chapter 11 was measured.

Diethyl dithiocarbamate silver arbitration colorimetric method.

A.8 Determination of heavy metals (Pb) of Weigh 2.00g ± 0.01g sample, placed in 100 mL beaker, add 5 mL of water to dissolve, add 2 mL of hydrochloric acid and evaporated to dryness on a water bath. Add 5 mL Water, 1 mL of hydrochloric acid, and then evaporated to dryness on a water bath. Add 0.5 mL glacial acetic acid, 20 mL of water to dissolve the residue, was added 1 drop of phenolphthalein indicator solution, Ammonia (11) was adjusted to pink, the following according to GB/T 5009.74-2003 Chapter 6 was measured.

Standard colorimetric solution with pipette Pipette 1mL lead standard solution [1 mL solution containing 0.010mg of lead (Pb)], placed in 50 mL Nessler colorimetric Tube, add 0.5 mL glacial acetic acid, 20 mL of water, add 1 drop of phenolphthalein indicator solution, aqueous ammonia (11) was adjusted to pink, the following according to GB/T 5009.74-2003 Chapter 6 were measured.

A.9 Determination of Lead Weigh 5.00g ± 0.01g sample for a limited test; or Weigh 5g samples, accurate to 0.01g, for the quantitative determination. The sample is placed 150 mL beaker, add 20 mL of water dissolved, add 1 mL solution of nitric acid (11), and evaporated to dryness on a water bath. The following press GB/T 5009.75-2003 Chapter 6 were measured.

Quantitative determination of the Arbitration Act.

A.10 Determination of Selenium Weigh 5.00g sample, accurate to 0.01g, placed in a 150 mL beaker, add 20 mL of water dissolved, add 1 mL solution of nitric acid (11), in water the bath was evaporated to dryness. The following press GB 5009.93-2010 The hydride generation atomic fluorescence spectrometry determination.