GB 1886.1-2021_English: PDF (GB1886.1-2021)
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Standard Title (Description) | Status | PDF |
| GB 1886.1-2021 | English | 185 |
Add to Cart
|
0--9 seconds. Auto-delivery
|
National food safety standard - Food additives - Sodium carbonate
| Valid |
GB 1886.1-2021
|
| GB 1886.1-2015 | English | 479 |
Add to Cart
|
3 days [Need to translate]
|
National Food Safety Standard -- Food Additives -- Sodium carbonate
| Obsolete |
GB 1886.1-2015
|
| GB 1886-2008 | English | 479 |
Add to Cart
|
3 days [Need to translate]
|
Food additive -- Sodium carbonate
| Obsolete |
GB 1886-2008
|
| GB 1886-1992 | English | 479 |
Add to Cart
|
4 days [Need to translate]
|
Food additive--Sodium carbonate
| Obsolete |
GB 1886-1992
|
| Standard ID | GB 1886.1-2021 (GB1886.1-2021) | | Description (Translated English) | National food safety standard - Food additives - Sodium carbonate | | Sector / Industry | National Standard | | Classification of Chinese Standard | X09 | | Word Count Estimation | 13,191 | | Date of Issue | 2021-02-22 | | Date of Implementation | 2021-08-22 | | Older Standard (superseded by this standard) | GB 1886.1-2015 | | Regulation (derived from) | National Health Commission Announcement No. 3 of 2021 | | Standard ID | GB 1886.1-2015 (GB1886.1-2015) | | Description (Translated English) | National Food Safety Standard -- Food Additives -- Sodium carbonate | | Sector / Industry | National Standard | | Classification of Chinese Standard | X42 | | Classification of International Standard | 67.220.20 | | Word Count Estimation | 12,111 | | Date of Issue | 2015-09-22 | | Date of Implementation | 2016-03-22 | | Older Standard (superseded by this standard) | GB 1886-2008 | | Regulation (derived from) | PRC National Health and Family Planning Commission 2015 No.8 | | Issuing agency(ies) | National Health and Family Planning Commission of the People's Republic of China | | Standard ID | GB 1886-2008 (GB1886-2008) | | Description (Translated English) | Food additive. Sodium carbonate | | Sector / Industry | National Standard | | Classification of Chinese Standard | X42 | | Classification of International Standard | 67.220.20 | | Word Count Estimation | 12,121 | | Date of Issue | 2008-06-25 | | Date of Implementation | 2009-01-01 | | Older Standard (superseded by this standard) | GB 1886-1992 | | Quoted Standard | GB/T 191-2008; GB/T 3049-2006; GB/T 3050-2000; GB/T 3051-2000; GB/T 6678; GB/T 6682-2008; GB/T 5009.76-2003; HG/T 3696.1; HG/T 3696.2; HG/T 3696.3 | | Adopted Standard | JECFA 2002, NEQ | | Drafting Organization | Tianjin Chemical Research and Design Institute | | Administrative Organization | National Standardization Technical Committee machines chemical Branch; National Food Additives Standardization Technical Committee | | Regulation (derived from) | Announcement of Newly Approved National Standards No. 12 of 2008 (No. 125 overall) | | Proposing organization | China Petroleum and Chemical Industry Association | | Issuing agency(ies) | General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, China National Standardization Administration Committee | | Summary | This Chinese standard specifies the requirements for food additives, sodium carbonate, test methods, inspection rules and signs, packaging, transport and storage. This standard applies to food additive sodium carbonate. The product is used in food processing as acidity regulator and the food industry processing aids. |
GB 1886.1-2021
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National food safety standard -
Food additives - Sodium carbonate
食品添加剂 碳酸钠
ISSUED ON: FEBRUARY 22, 2021
IMPLEMENTED ON: AUGUST 22, 2021
Issued by: National Health Commission of the People's Republic of China;
State Administration for Market Regulation.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Molecular formula and relative molecular mass ... 4
3 Technical requirements ... 4
Annex A Inspection methods ... 6
National food safety standard -
Food additives - Sodium carbonate
1 Scope
This Standard is applicable to anhydrous sodium carbonate as a food additive
produced by the Hou-Soda method, ammonia-soda method or trona processing
method. At the same time, it is also applicable to the food additive sodium
carbonate decahydrate produced by recrystallization of food additive anhydrous
sodium carbonate.
2 Molecular formula and relative molecular mass
2.1 Molecular formula
Anhydrous sodium carbonate: Na2CO3
Sodium carbonate decahydrate: Na2CO3·10H2O
2.2 Relative molecular mass
Anhydrous sodium carbonate: 105.99 (according to 2018 international relative
atomic mass)
Sodium carbonate decahydrate: 286.14 (according to 2018 international
relative atomic mass)
3 Technical requirements
3.1 Sensory requirements
The sensory requirements shall meet the requirements of Table 1.
Table 1 -- Sensory requirements
3.2 Physical and chemical indicators
Annex A
Inspection methods
WARNING: Some reagents used in the test method in this Standard are
toxic or corrosive. Be careful when operating! If splashed on the skin,
rinse immediately with water. Severe cases shall be treated immediately.
For reagents containing highly toxic drugs, management shall be strictly
in accordance with relevant regulations. Avoid inhalation or contact with
skin when using. It shall be carried out in a fume hood if necessary. People
with wounds in the exposed area shall not be touched. When using
volatile acid, it shall be carried out in a fume hood. When using flammable
products, it is strictly forbidden to use an open flame for heating.
A.1 General
The reagents and water used in this Standard refer to analytically-pure reagents
and grade three water specified in GB/T 6682 when other requirements are not
indicated. All standard solutions, preparations and products for the
determination of impurities used in the test, when no other requirements are
specified, are prepared according to GB/T 601, GB/T 602, GB/T 603. The
solution used refers to aqueous solution when it is not specified which solvent
is used for preparation.
A.2 Identification test
A.2.1 Reagents and materials
A.2.1.1 Hydrochloric acid.
A.2.1.2 Magnesium sulfate solution: 120g/L.
A.2.1.3 Calcium oxide saturated solution. Preparation: Weigh about 3g of
calcium oxide, to the nearest of 0.1g. Place in a reagent bottle. Add 1000mL of
water. Cap it. After shaking vigorously, place it for clarification. Take the
supernatant when using.
A.2.1.4 Glass rod with platinum wire ring.
A.2.2 Identification methods
A.2.2.1 Preparation of test solution: Weigh about 20g of specimen, to the
nearest of 0.1g. Place in a beaker. Add 100mL of water. Make it dissolved.
A.2.2.2 Use hydrochloric acid to wet the platinum wire ring. Burn to colorless
Where,
m1 - The mass of the specimen and the porcelain crucible before burning, in
grams (g);
m2 - The mass of the specimen and the porcelain crucible after burning, in
grams (g);
m - The specimen mass, in grams.
The test results are based on the arithmetic mean of the parallel determination
results. The absolute difference between two independent determination results
obtained under repeatability conditions is not more than 0.04%.
A.4 Determination of total alkali content (as Na2CO3)
A.4.1 Method summary
Take bromocresol green-methyl red mixed solution as indicator liquid. Use
hydrochloric acid standard titration solution to titrate.
A.4.2 Reagents and materials
A.4.2.1 Hydrochloric acid standard titration solution: c(HCl)=1mol/L.
A.4.2.2 Bromocresol green-methyl red mixed indicator solution.
A.4.3 Analysis steps
A.4.3.1 Determination of total alkali content (on dry basis)
Weigh about 1.7g of specimen that has been burnt to a constant mass
according to A.3, to the nearest of 0.0002g. Place in an Erlenmeyer flask. Use
50mL of water to dissolve the specimen. Add 10 drops of bromocresol green-
methyl red mixed indicator solution. Use hydrochloric acid standard titration
solution to titrate till the solution is from green to dark red. Boil 2min. After
cooling, continue to titrate to dark red as the end point. Conduct blank test at
the same time.
In the blank test, except for not adding the specimen, the other operations and
the type and number of reagents added (except the standard titration solution)
are the same as the determination test.
A.4.3.2 Determination of total alkali content (based on wet basis)
Weigh about 1.7g of anhydrous sodium carbonate or about 4.6g of sodium
carbonate decahydrate specimen, to the nearest of 0.0002g. Place in an
Erlenmeyer flask. Use 50mL of water to dissolve the specimen. Add 10 drops
A.5.2.1 Hydrochloric acid solution: 1+3.
A.5.2.2 Anhydrous sodium carbonate solution: 100g/L.
A.5.2.3 Phenolphthalein indicator solution: 10g/L.
A.5.2.4 Pickling asbestos: Take an appropriate amount of pickled asbestos and
place it in a beaker. Add hydrochloric acid solution. Boil 20min. Use a Buchner
funnel to filter and wash till it is neutral. Take out and soak in sodium carbonate
solution. Boil 20min. Use the Buchner funnel to filter. Use water to wash till it is
neutral (use phenolphthalein solution to inspect). Take it out and place it in a
beaker. Add water to make a paste for future use.
A.5.2.5 Asbestos filter paper.
A.5.3 Instruments and equipment
A.5.3.1 Gooch crucible: Capacity is 30mL.
A.5.3.2 Electric heating constant temperature drying oven: temperature control
range is 110°C±5°C.
A.5.4 Analysis steps
A.5.4.1 Laying of ancient crucible
A.5.4.1.1 Ancient crucible method for pickling asbestos
Place the Gooch crucible on the suction-filtration flask. Spread a layer of pickled
asbestos evenly on the top and bottom of the sieve. During suction-filtration,
use a flat glass rod to press it tightly. Each layer is about 3mm thick. Use
50°C±5°C water to wash till there is no asbestos fiber in the filtrate. Place the
Gooch crucible in an electric heating constant temperature drying box. Dry at
110°C±5°C. Weigh. Repeat washing and drying until the mass is constant.
A.5.4.1.2 Asbestos filter paper ancient crucible method
Place the Gooch crucible on the suction-filtration flask. Lay a layer of asbestos
filter paper under the sieve. Lay two layers of asbestos filter paper on the sieve.
During suction-filtration, use a flat glass rod to press it tightly. Use 50°C±5°C
water to wash to the filter paper. Place the Gooch crucible in an electric heating
constant temperature drying box. Dry at 110°C±5°C. Weigh. Repeat washing
and drying until the mass is constant.
A.5.4.2 Determination
Weigh about 40g of specimen, to the nearest of 0.01g. Put in a beaker. Add
400mL of water at about 40°C to make it dissolved. Keep the solution at
dilute to the scale mark. Shake well.
A.6.1.2.5 Silver nitrate standard titration solution: c(AgNO3)=0.05mol/L.
a) Preparation: Weigh 8.75g of silver nitrate, to the nearest of 0.01g. Dissolve
it in 1000mL of water. Shake well. The solution is stored in a brown bottle.
b) Calibration: Use a pipette to take 5mL of sodium chloride standard solution.
Place in a 100mL beaker. Add 40mL of water. Put the electromagnetic
stirrer into it. Place the beaker on the electromagnetic stirrer. Turn on the
stirrer. Add 2 drops of bromophenol blue indicator solution. Add nitric acid
solution dropwise to just yellow. Insert the measuring electrode and
reference electrode into the solution. Connect the potentiometer wiring.
Adjust the potentiometer zero point. Record the starting potential value.
Use silver nitrate standard titration solution to titrate. Add 4.00mL first.
Add 0.10mL successively. Record the total volume and the corresponding
potential value E after each addition of silver nitrate standard titration
solution. Calculate the difference ΔE2 between the continuously
increasing potential value ΔE1 and the increasing potential value ΔE1. The
maximum value of ΔE1 is the end point of the titration. After the end point,
continue to record a potential value E.
For the record format, see Annex C of GB/T 3050-2000.
The volume of the silver nitrate standard titration solution consumed by the
titration to the end point V1 is expressed in milliliters (mL). Calculate
according to formula (A.4).
Where,
V2 - The value of the volume of the silver nitrate standard titration solution
added before the potential increment value ΔE1 reaches the maximum value,
in milliliters (mL);
b - The last positive value of ΔE2;
B - The sum of last positive value of ΔE2 and the absolute value of the first
negative value;
V3 - The value of the volume of the silver nitrate standard titration solution
added for the last time before the potential increment ΔE1 reaches the
maximum, in milliliters (mL).
c) Calculation: The concentration c1 of the silver nitrate standard titration
preparation of reference solution, in milliliters (mL);
1000 - The conversion factor;
M1 - The molar mass of sodium chloride, in grams per mole (g/mol) [M
(NaCl)=58.44];
m7 - The specimen mass, in grams (g);
w0 - The mass fraction of ignition reduction measured in A.3.
The test results are based on the arithmetic mean of the parallel determination
results. The absolute difference between two independent determination results
obtained under repeatability conditions is not more than 0.02%.
A.7 Determination of iron (Fe) (on dry basis)
A.7.1 Method summary
Same as Chapter 3 of GB/T 3049-2006.
A.7.2 Reagents and materials
Same as Chapter 4 of GB/T 3049-2006.
A.7.3 Instruments and equipment
Same as Chapter 5 of GB/T 3049-2006.
A.7.4 Analysis steps
A.7.4.1 Preparation of specimen solution
Weigh about 10g of specimen, to the nearest of 0.01g. Place in a beaker. Add
a small amount of water to moisten. Cover with a watch glass. Drop 35mL of
hydrochloric acid solution (1+1). Boil 3min~5min. Cool down (filter if necessary).
Transfer all into a 250mL volumetric flask. Use water to dilute to the scale mark.
Shake well.
A.7.4.2 Preparation of blank test solution
Measure 7mL of hydrochloric acid solution (1+1). Place in a 100mL beaker. Add
ammonia solution (2+3) dropwise to neutralize to neutral (use a precision pH
test paper to inspect).
A.7.4.3 Drawing of working curve
See 6.3 of GB/T 3049-2006. Choose a 4cm or 5cm absorption cell and the
corresponding iron standard solution volume.
......
GB 1886.1-2015
(National food safety standards for food additives sodium)
National Standards of People's Republic of China
National Food Safety Standard
Food additive sodium carbonate
Issued on. 2015-09-22
2016-03-22 implementation
People's Republic of China
National Health and Family Planning Commission released
Foreword
This standard replaces GB 1886-2008 "food additive sodium carbonate."
This standard compared with GB 1886-2008, the main changes are as follows.
--- Standard name was changed to "national food safety standards for food additives sodium carbonate."
National Food Safety Standard
Food additive sodium carbonate
1 Scope
This standard applies to food additive sodium carbonate.
2 molecular formula and relative molecular mass
Formula 2.1
Na2CO3
2.2 relative molecular mass
105.99 (according to 2007 international relative atomic mass)
3 Technical requirements
3.1 Sensory requirements
Sensory requirements shall comply with the requirements of Table 1.
Table 1 Sensory requirements
Project requires test methods
Color White
Status crystalline powder
Take the right amount of sample is placed in a clean, dry white porcelain dish,
In natural light, observe its color and status
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
Total Alkalinity (in Na2CO3 dollars) (dry basis), w /% ≥ 99.2 Appendix A A.5
Total Alkalinity (in Na2CO3 dollars) (with moisture basis), w /% ≥ 97.9 Appendix A A.5
Chloride (NaCl) (dry basis), w /% ≤ 0.70 A.6 in Appendix A
Iron (Fe) (dry basis), w /% ≤ 0.0035 Appendix A A.7
Heavy metals (Pb)/(mg/kg) ≤ 10.0 Appendix A A.8
Arsenic (As)/(mg/kg) ≤ 2.0 GB 5009.76
Water insoluble matter (dry basis), w /% ≤ 0.03 A.9 in Appendix A
Appendix A
Testing method
A.1 Safety Tips
Reagents The standard test methods used for toxic or corrosive, care should be taken. As should be immediately splashed on the skin
Rinsed with water, severe cases should be treated immediately. When using a volatile acid, to be carried out in a fume hood.
A.2 General Provisions
This standard reagents and water in the absence of other specified requirements, refer to the three water analytical reagent and GB/T 6682 regulations. test
The required standard solution, impurity standard solution, preparations and products, did not indicate when the other requirements according to GB/T 601, GB/T 602,
GB/T 603 provisions of the preparation. Solution was used in the tests did not indicate what is formulated with solvent, it refers to an aqueous solution.
A.3 Identification Test
A.3.1 Reagents and materials
A.3.1.1 hydrochloric acid.
A.3.1.2 magnesium sulfate solution. 120g/L.
A.3.1.3 saturated solution of calcium oxide.
Weigh about 3g calcium oxide, accurate to 0.1g, placed on the reagent bottle, added 1000mL water, cover stopper, shake vigorously after placing Cheng
clear. Supernatant using.
A.3.1.4 glass rod with a platinum wire ring.
A.3.2 Identification method
A.3.2.1 Preparation of test solution. Weigh about 20g sample, accurate to 0.1g, placed in a beaker, 100mL of water was added and dissolved.
A.3.2.2 wetting platinum wire ring with hydrochloric acid, colorless to burn in the flame, then dipped a little in the test solution combustion flame, the flame that was bright
yellow.
A.3.2.3 released in the test solution of hydrochloric acid was added dropwise while the carbon dioxide gas is passed into a saturated solution of calcium oxide to a white turbid liquid, continued
Ventilation cloudy to clear.
A.3.2.4 magnesium sulfate solution was added dropwise in the test solution, i.e., a white precipitate.
A.4 Determination of loss on ignition
A.4.1 Method summary
Samples were heated at 250 ℃ ~ 270 ℃ to constant mass. Loss of free water and sodium bicarbonate by the decomposition of water and dioxide when heated
Carbon, calculated loss on ignition.
A.4.2 Instruments and Equipment
A.4.2.1 weighing bottle. φ30mm × 25mm or porcelain crucible capacity 30mL.
A.4.2.2 electric oven or high-temperature furnace can be controlled at 250 ℃ ~ 270 ℃.
A.4.3 Analysis step
Previously at 250 ℃ ~ 270 ℃ dried to constant mass weighing bottles or porcelain crucible Weigh about 2g sample in the precise
0.0002g, placed in a high temperature oven or electric oven, heated to a constant mass at 250 ℃ ~ 270 ℃.
A.4.4 Calculation Results
Mass loss on ignition fraction w0, according to equation (A.1) Calculated.
w0 =
m1-m2
m × 100%
(A.1)
Where.
Mass m1 --- specimens and weighing bottle or porcelain crucible, in grams (g);
m2 --- heating quality specimens and weighing bottle or porcelain crucible after constant in units of grams (g);
M --- the quality of the sample, in grams (g).
Take the arithmetic mean of the parallel determination results of the measurement results, the results of parallel determination of the absolute difference is not more than 0.04%.
A.5 Total Alkalinity (in Na2CO3 meter) measurement
A.5.1 Method summary
Bromocresol green - methyl red mixed solution as the indicator solution, titration with hydrochloric acid standard solution titration.
A.5.2 Reagents and materials
A.5.2.1 hydrochloric acid standard titration solution. c (HCl) = 1mol/L.
A.5.2.2 Bromocresol green - methyl red mixed indicator solution.
A.5.3 Instruments and Equipment
A.5.3.1 weighing bottle (φ30mm × 25mm) or porcelain crucible (capacity 30mL).
A.5.3.2 electric oven or high-temperature furnace. can be controlled at 250 ℃ ~ 270 ℃.
A.5.4 Analysis step
A.5.4.1 alkali content (dry basis) of the Determination
Weigh 250 ℃ ~ 1.7g been dried to a constant mass of the sample 270 ℃, accurate to 0.0002g, set conical flask with 50mL
Samples dissolved in water, add 10 drops of bromocresol green - methyl red mixed indicator solution, titration with hydrochloric acid standard solution titration solution from green to dark red
Color, boiling 2min, cooled continue titration to dark red for the end. While doing the blank test.
A.5.4.2 Total alkali content (wet basis) Determination
Weigh 1.7g sample, accurate to 0.0002g, placed in a conical flask, dissolved in 50mL water, add 10 drops of bromocresol green - methyl red mixed
Indicator solution, titration with hydrochloric acid standard titration solution until the solution turns from green to dark red, boiling 2min, after cooling to continue titration to dark red
end. While doing the blank test.
A.5.5 Calculation Results
Total Alkalinity (in Na2CO3 meter) mass fraction w1, according to equation (A.2) Calculated.
w1 =
c × (V-V0) × M
m3 × 1000 ×
100% (A.2)
Where.
c --- hydrochloric acid standard titration solution concentration, in units of moles per liter (mol/L);
V --- titrated sample solution of hydrochloric acid standard volumetric consumption volume of the solution, in milliliters (mL);
Volume V0 --- hydrochloric acid standard titration titration solution consumed in the blank test solution, in milliliters (mL);
--- The M sodium carbonate molar mass in grams per mole (g/mol), [M (
2Na2CO3
) = 53.00];
M3 --- the quality of the sample, in grams (g);
1000 --- conversion factor.
The results parallel arithmetic mean of the measurement results shall prevail. In two independent determination results obtained under repeatability conditions absolute difference
Not more than 0.2%.
A.6 chloride (as NaCl) (dry basis) of the Determination
A.6.1 potentiometric titration
A.6.1.1 Method summary
See GB/T 3050-2000 Chapter 2.
A.6.1.2 Reagents and materials
A.6.1.2.1 nitric acid solution. 11.
A.6.1.2.2 saturated solution of potassium nitrate.
A.6.1.2.3 bromophenol blue indicator solution. 1g/L ethanol solution.
A.6.1.2.4 chloride standard solution. c (NaCl) = 0.05mol/L.
Weigh 2.9225g advance at 500 ℃ ~ 600 ℃ dried to a constant mass of the reference sodium chloride, accurate to 0.0002g, placed burning
Cup, add water to dissolve all moved into 1000mL volumetric flask, add water to the mark.
A.6.1.2.5 standard silver nitrate titration solution. c (AgNO3) = 0.05mol/L.
Preparation. Weigh 8.75g of silver nitrate, accurate to 0.01g, was dissolved in 1000mL of water, shake. Solution was kept in a brown bottle.
Calibration. Pipette Pipette 5mL sodium chloride standard solution, placed in 100mL beaker, add 40mL water, add electromagnetic stirrer,
The beaker was placed on a magnetic stirrer, agitator, add 2 drops of bromophenol blue indicator solution, nitric acid solution was dropped to just yellow. The electrical measurements
Electrode and a reference electrode inserted into the solution, the potentiometer connected wiring, adjustment potentiometer zero potential value of recording start. With standard silver nitrate titration solution
Titration, to join 4.00mL, then successively added 0.10mL. And the total volume of the corresponding record each addition of the standard silver nitrate titration solution after
The potential value E, calculate the difference between the continuous increase of ΔE1 and increased the potential value of the potential value ΔE1 between ΔE2. The maximum ΔE1
Titration is the end, the end and then continue to record a potential value E.
Recording format, see GB/T 3050-2000 Appendix C.
Titration to the end of the consumption of the standard silver nitrate titration solution volume V1 (mL), according to equation (A.3) Calculated.
V1 = V2
B × V3
(A.3)
Where.
V2 --- ΔE1 potential incremental value reaches the maximum volume previously added to the standard silver nitrate titration solution in milliliters (mL);
b --- ΔE2 last positive value;
B --- ΔE2 last positive and negative for the first time the absolute value of the sum;
V3 --- potential incremental value ΔE1 reach the last time before the maximum standard silver nitrate titration solution volume in milliliters
(ML).
Calculation of the standard silver nitrate titration solution concentration c1 (AgNO3) (mol/L), according to equation (A.4) Calculated.
c1 =
c2 × V5
V4
(A.4)
Where.
C2 --- sodium chloride standard solution concentration, expressed in moles per liter (mol/L);
Volume Pipette V5 --- titration of sodium chloride standard solution, in milliliters (mL);
Volume V4 --- titration consumption standard silver nitrate titration solution in milliliters (mL).
A.6.1.3 instruments and equipment
See GB/T 3050-2000 Chapter 5.
A.6.1.4 analysis step
Weigh about 1g sample, accurate to 0.01g, placed in 100mL beaker, add 40mL of water to dissolve. Following in A.6.1.2.5 into
OK, since "into electromagnetic stirrer" to start "before the end of a record potential value E" so far. But do not first nitric acid was added 4.00mL
Silver Standard Solution. While doing the blank test.
A.6.1.5 Calculation Results
Chloride (NaCl) (dry basis) of the mass fraction w2, according to equation (A.5) Calculated.
w2 =
c3 × (V7-V6) × M1 × 100
m4 × (100-w0) × 1000 ×
100% (A.5)
Where.
Concentration c3 --- standard silver nitrate titration solution, expressed in moles per liter (mol/L);
Volume V7 --- titration consumption standard silver nitrate titration solution in milliliters (mL);
Volume V6 --- blank test consumption standard silver nitrate titration solution in milliliters (mL);
--- Ml molar mass of sodium chloride, in units of grams per mole (g/mol), [M (NaCl) = 58.44];
M4 --- the quality of the sample, in grams (g);
w0 --- A.4 Quality Score from the measured loss on ignition;
1000 --- conversion factor.
The results parallel arithmetic mean of the measurement results shall prevail. In two independent determination results obtained under repeatability conditions absolute difference
Not more than 0.02%.
A.6.2 Mercury Method (Arbitration Act)
A.6.2.1 Method summary
In slightly acidic water or ethanol - water solution with a strong solution of nitrate mercury standard titration ionized chlorine into chloride ions weakly ionized
Mercury, with diphenylcarbazone indicator with an excess of hydrazine generates Hg2 purple complex to determine the end point.
A.6.2.2 Reagents and materials
A.6.2.2.1 nitric acid solution. 11.
A.6.2.2.2 nitric acid solution. 17.
A.6.2.2.3 sodium hydroxide solution. 40g/L.
A.6.2.2.4 nitrate mercury standard titration solution. c [
2Hg
(NO3) 2 · H2O] = 0.05mol/L.
A.6.2.2.5 bromophenol blue indicator solution. 1g/L.
A.6.2.2.6 diphenylcarbazone hydrazine indicator solution. 5g/L.
A.6.2.3 instruments and equipment
Buret. indexing is 0.01mL.
A.6.2.4 analysis step
A.6.2.4.1 Preparation of reference solution
In 250mL Erlenmeyer flask was added 40mL of water and 2 drops of bromophenol blue indicator solution. Was added dropwise a solution of nitric acid (A.6.2.2.1) to the solution from blue
Just become yellow, then drop 2 to 3 drops of excess. Join 1mL diphenylcarbazone hydrazine indicator solution, titration with mercury nitrate standard solution titration solution
From yellow to purple, record volume of mercury nitrate titration standard solution used. This solution was prepared prior to use.
A.6.2.4.2 measured sample
Weigh about 2g specimen to the nearest 0.01g, placed in 250mL conical flask, add water to dissolve 40mL, add 2 drops of bromophenol blue indicator solution drops
Was added nitric acid (A.6.2.2.1) and after to yellow, then dropping sodium hydroxide solution to the blue, and then a solution of nitric acid (A.6.2.2.2) adjusted exactly
Yellow and then excess 2 drops to 3 drops, added 1mL diphenylcarbazone hydrazine indicator solution, titration with mercury nitrate standard solution titration to change from yellow
The same ratio as the reference solution purple is the end.
Save the mercury-containing waste after titration up, according to GB 3051-2000 Annex D for processing.
A.6.2.5 Calculation Results
Chloride (NaCl) (dry basis) of the mass fraction w3, according to equation (A.6) Calculated.
w3 =
c4 × (V9-V8) × M2 × 100
m5 × (100-w0) × 1000 ×
100% (A.6)
Where.
c4 --- nitrate mercury standard titration solution concentration, in units of moles per liter (mol/L);
V9 --- titration volume consumed mercury nitrate titration standard solution, in milliliters (mL);
V8 --- reference solution was prepared in the volume of mercury nitrate standard titration solution consumption in milliliters (mL);
The M2 --- molar mass of sodium chloride, in units of grams per mole (g/mol), [M (NaCl) = 58.44];
M5 --- the quality of the sample, in grams (g);
w0 --- A.4 Quality Score from the measured loss on ignition;
1000 --- conversion factor.
The results parallel arithmetic mean of the measurement results shall prevail. In two independent determination results obtained under repeatability conditions absolute difference
Not more than 0.02%.
(Fe) (dry basis) of iron was measured A.7
A.7.1 Method summary
With GB/T 3049-2006 Chapter 3.
A.7.2 Reagents and materials
With GB/T 3049-2006 Chapter 4.
A.7.3 Instruments and Equipment
See GB/T 3049-2006 Chapter 5.
A.7.4 Analysis step
A.7.4.1 Preparation of test solution
It weighs about 10g sample, accurate to 0.01g, beaker, add a little water wet, covered with a watch glass, dropping 35mL hydrochloric acid solution
(11), boil 3min ~ 5min. Cooling (if necessary filtering) all transferred to 250mL volumetric flask, dilute to the mark, shake.
A.7.4.2 Preparation of the blank test solution
7mL amount of hydrochloric acid solution (11), placed in 100mL beaker, was added dropwise a solution of aqueous ammonia (23) to neutral (pH test precision
Paper test).
A.7.4.3 draw the curve
See GB/T 3049-2006 6.3. Select 4cm 5cm iron absorption cell and the corresponding volume or standard solution.
A.7.4.4 Determination
Pipette with a pipette 50mL test solution and the blank test solution 50mL, (18) or a hydrochloric acid solution was washed with aqueous ammonia solution
(13) was adjusted to a pH of about 2 (with a precision pH test paper). All were transferred to 100mL volumetric flask. Following in the
GB/T 3049-2006 6.4 absorbance measurement. Measuring the absorbance of the test solution and blank solution.
A.7.5 Calculation Results
Iron (Fe) (dry basis) of the mass fraction w4, according to equation (A.7) calculated as follows.
w4 =
(M8-m6) × 10-3 × 100 × 250
m7 × (100-w0) × 50 ×
100% (A.7)
Where.
m8 --- According to the test solution absorbance measured, quality iron isolated from the working curve, in milligrams (mg);
m6 --- blank test solution based on the absorbance measured, isolated from the working curve of iron mass, in milligrams (mg);
M7 --- the quality of the sample, in grams (g);
w0 --- A.4 measured by the loss on ignition of the mass fraction.
The results parallel arithmetic mean of the measurement results shall prevail. In two independent determination results obtained under repeatability conditions absolute difference
Not more than 0.0005%.
A.8 Determination of heavy metals (Pb) of
A.8.1 Method summary
Under weakly acidic conditions pH3 ~ 4, heavy metal ions in the sample and the role of hydrogen sulfide to produce brown-black, lead to the same standard of treatment
Comparison solution.
A.8.2 Reagents and solutions
A.8.2.1 hydrochloric acid solution. 14.
A.8.2.2 ammonia solution. 12.
A.8.2.3 glacial acetic acid. 115.
A.8.2.4 solution of sodium sulfide or hydrogen sulfide solution.
A.8.2.5 Lead standard solution. 1mL lead (Pb) 0.010mg, Extemporaneous. Pipette Pipette 10mL lead standard solution, placed
100mL volumetric flask, dilute to the mark, shake.
A.8.2.6 phenolphthalein indicator solution. 10g/L.
A.8.3 Analysis step
A.8.3.1 Preparation of test solution
Weigh 2.00g ± 0.01g sample was placed in 100mL beaker, add 5mL water, cover the surface of the dish, the cup slowly added 17mL
Hydrochloric acid solution, boiled for 5min, add 1 drop of phenolphthalein indicator solution was cooled, neutralized with aqueous ammonia solution to a pink and.
All transferred 50mL colorimetric tube, add 2mL acetic acid solution, 10mL solution of sodium sulfide or hydrogen sulfide solution, add water to the mark, shake
uniform. Place after 10min in the dark and relatively standard, it shall not be deeper than the standard.
A.8.3.2 Preparation of standard solutions for more than
Standard with a pipette of 2mL lead standard solution, placed in 100mL beaker. Press A.8.3.1 The "plus 5mL water" and start
The test solution at the same time in the same manner.
A.9 Determination of water insoluble matter (dry basis) of
A.9.1 Method summary
Samples were dissolved in water 50 ℃ ± 5 ℃, the insoluble was filtered, washed with, dried and weighed.
A.9.2 Reagents and materials
A.9.2.1 hydrochloric acid solution. 13.
A.9.2.2 Anhydrous sodium carbonate solution. 100g/L.
A.9.2.3 Phenolphthalein solution. 10g/L.
A.9.2.4 Pickling asbestos.
Acid appropriate amount of asbestos in a beaker, was added a solution of hydrochloric acid, boiled 20min, filtered through a Buchner funnel and washed until neutral. Remove soaked
In sodium carbonate solution and boiled 20min, filtered through a Buchner funnel and washed with water to neutral (phenolphthalein test solution), remove the beaker plus
Water into a paste and set aside.
A.9.2.5 asbestos filter paper.
A.9.3 Instruments and Equipment
A.9.3.1 Gooch crucible. capacity 30mL.
A.9.3.2 electric oven. can be controlled at 110 ℃ ± 5 ℃.
A.9.4 Analysis step
A.9.4.1 Gooch crucible shop system
A.9.4.1.1 Pickling asbestos Gooch crucible method (Arbitration Act)
The Gooch crucible filtration bottle placed on the sieve up and down the uniform layer of pickled asbestos, while suction side pressed with a flathead glass rod, each
Thickness of 3 mm. 50 ℃ ± 5 ℃ was washed with water until the filtrate does not contain asbestos fibers. The Gooch crucible placed in an electric oven at
110 ℃ ± 5 ℃ weighed after dried, repeated washing and drying to a constant quality.
A.9.4.1.2 asbestos paper Gooch crucible method
The Gooch crucible filtration bottle placed on the lower berth layer of asbestos paper sieve, sieve capped at two asbestos filter, suction side edge with a flat head
Pressed glass rod. Filter paper was washed with water, 5 ℃ 50 ℃ ±. The Gooch crucible placed in an electric oven at 110 ℃ ± 5 ℃ after drying weighed heavy
Re-washed, dried to a constant mass.
A.9.4.2 Determination
Weigh about 40g specimen to the nearest 0.01g, placed in a beaker, was added 400mL of water about 40 ℃ dissolved, the solution was maintained at
50 ℃ ± 5 ℃. Use has been constant quality Gooch crucible filtration, washed with 50 ℃ ± 5 ℃ with water until the filtrate take 20mL add 2 drops of phenolphthalein after
So far no significant red, wash water control a total volume of 800mL. Remove Gooch crucible placed in 110 ℃ ± 5 ℃ electric oven to quality
Constant.
A.9.5 Calculation Results
Water insoluble matter (dry basis) of the mass fraction w5 meter, according to equation (A.8) Calculated.
w5 =
m10 × 100
m9 × (100-w0) ×
100% (A.8)
Where.
m10 --- water insoluble mass in grams (g);
M9 --- the quality of the sample, in grams (g);
w0 --- A.4 measured by the loss on ignition of the mass fraction.
The results parallel arithmetic mean of the measurement results shall prevail. In two independent determination results obtained under repeatability conditions absolute difference
Not more than 0.006%.
......
GB 1886-2008
Food additive.Sodium carbonate
ICS 67.220.20
X42
National Standards of People's Republic of China
Replacing GB 1886-1992
Food additive sodium carbonate
Posted 2008-06-25
2009-01-01 implementation
Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China
Standardization Administration of China released
Foreword
The standard Chapter 4 and Chapter 7 are mandatory, others are recommended.
This standard and the Joint Expert Committee on Food Additives of FAO and the World Health Organization (FAO/WHO) of the United Nations (JECFA)
2002 "sodium carbonate" (in English) of non-equivalent.
This standard replaces GB 1886-1992 "food additive sodium carbonate."
The main difference between this standard and GB 1886-1992 are as follows.
--- Total Alkalinity added (wet basis) 97.9% (edition 4.2);
--- Iron (as Fe) content of the index by the moisture basis to a dry basis from 0.0040% to 0.0035% Adjustment (1992 edition
Chapter 3, 4.4.5; 4.2,5.7.5 edition);
--- Cancellation loss on ignition of the indicator (Chapter 3, 1992 edition);
--- Water-insoluble content of the index is adjusted to 0.040% (dry basis) 0.03% (1992 Edition Chapter 3; edition 4.2);
--- Determination of total alkali content increases moisture basis measurement method (Excerpts 5.5.4.2);
--- Determination of heavy metals in the increased use of sodium sulfide solution (1992 Version 4.5; this version 5.8);
--- Determination of arsenic increase diethyl dithiocarbamate silver colorimetry, and set to the Arbitration Act (edition 5.9);
--- Determination of water-insoluble matter content in asbestos paper added Gooch crucible method, pickled asbestos Gooch crucible law Arbitration Act (1992 version 4.8; this
Version 5.11);
--- Increasing the pouch packaging requirements (Excerpts 8.1.3).
The standard proposed by China Petroleum and Chemical Industry Association.
This standard by the National Standardization Technical Committee chemical inorganic chemicals Club (SAC/TC63/SC1) and the National Food Additives Standardization
Technical Committee (SAC/TC11) common focal point.
This standard drafting units. Tianjin Chemical Engineering Research and Design Institute, Tianjin Soda Plant, Tangshan Sanyou Chemical Co., Tongbai-shelf alkaline mineral
Limited Liability Company, Xinjiang Chemical Industry (Group) Co., Ltd. Shuanghe alkali industry subsidiaries, Gol Sunite Alkali Industry Co., Ltd, China Stone
Nanjing Chemical Industry Group Co., Ltd. Lianyungang Soda Plant, Shandong Haihua Group Co., Ltd. Soda Plant, Zigong Honghe Chemical Company Limited
Secretary, Dahua Group Co., Ltd., Qingdao Soda Ash Industrial Co., Ltd., Jiangsu Debang Xinghua Chemical Co., Ltd., Hubei Yihua Group has
Limited liability company.
The main drafters of this standard. Lu Yong, Wang Yan, Lai investigation, Xieqiu Li, Wang Bin, Ma Wen-yuan, Geng Wen law, SUN Shu-Hong, Kim Lan, Wang Hang, Wang Yuan,
American National Biography, FORESTRY AND Liu Ruo.
The standard standard replaces the previous editions.
--- GB 1886-1983, GB 1886-1992.
Food additive sodium carbonate
1 Scope
This standard specifies requirements for a food additive sodium carbonate, test methods, inspection rules and signs, packaging, transportation and storage.
This standard applies to food additive sodium carbonate. The product as acidity regulator and food processing aids in food processing.
2 Normative references
The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent
Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research
Study whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.
GB/T 191-2008 Packaging - Pictorial signs (ISO 780.1997, MOD)
General Method GB/T 3049-2006 industrial chemical products, determination of iron content 1,10 Philippines morpholino spectrophotometric
Method (ISO 6685. 1982, IDT)
GB/T 3050-2000 inorganic chemical products in general potentiometric method for determination of chloride content
GB/T 3051-2000 Inorganic chemical products for the general method of determination of chloride content of mercury Method
GB/T 6678 General Principles for Sampling Chemical Products
GB/T 6682-2008 analytical laboratory use specifications and test methods (ISO 3696. 1987, MOD)
Determination of GB/T 5009.76-2003 arsenic in food additives
Preparation of standard titration solution of HG/T 3696.1 inorganic chemical products, chemical analysis
Preparation of HG/T 3696.2 inorganic chemical products, chemical analysis of impurity standard solution
Preparations of HG/T 3696.3 inorganic chemical products, chemical analysis
3 formula and relative molecular mass
Molecular formula. Na2CO3
Molecular weight. 105.99 (according to 2007 international relative atomic mass)
4 Requirements
4.1 Appearance. food additive sodium carbonate is a white crystalline powder.
4.2 Requirements. food additive sodium carbonate should meet the requirements of Table 1.
Table 1 Requirements
Item Index
Total Alkalinity (in Na2CO3 dollars) (dry basis), /% ≥ 99.2
Total Alkalinity (in Na2CO3 dollars) (moisture basis), /% ≥ 97.9
Chloride (NaCl) (dry basis), /% ≤ 0.70
Iron (Fe) (dry basis), /% ≤ 0.0035
Heavy metals (Pb), /% ≤ 0.0010
Arsenic (As), /% ≤ 0.0002
Water insoluble matter (dry basis), /% ≤ 0.03
5 Test methods
5.1 Safety Tips
Reagents The standard test methods used for toxic or corrosive, be careful when operating! As should be immediately splashed on the skin
Rinsed with water, severe cases should be treated immediately. When using a volatile acid, to be carried out in a fume hood.
5.2 General Provisions
This standard reagents and water, did not indicate when the other requirements, refer to analytically pure reagents and GB 6682-2008 stipulated three
Grade water.
Standard solution, impurity standard solution, preparations and articles of the standard tests required in the absence of other requirements specified according to
HG/T 3696.1, HG/T 3696.2, the provisions prepared HG/T 3696.3 of.
5.3 Identification of appearance
In natural light, visually distinguish samples taken.
5.4 Identification
5.4.1 Reagents and materials
5.4.1.1 hydrochloric acid;
5.4.1.2 magnesium sulfate solution. 120g/L;
5.4.1.3 saturated solution of calcium oxide;
Weigh about 3g calcium oxide, accurate to 0.1g, placed on the reagent bottle, added 1000mL water, cover stopper, shake vigorously after placing Cheng
clear. Supernatant using.
5.4.1.4 glass rod with a platinum wire ring.
5.4.2 Identification Methods
5.4.2.1 Preparation of test solution
Weigh about 20g sample, accurate to 0.1g, placed in a beaker, 100mL of water was added and dissolved.
5.4.2.2 moistened with hydrochloric acid, a platinum wire ring, colorless to burn in the flame, then dipped a little in the test solution combustion flame, the flame that was bright
yellow.
5.4.2.3 released in the test solution of hydrochloric acid was added dropwise while the carbon dioxide gas is passed into a saturated solution of calcium oxide to a white turbid liquid, continued
Ventilation cloudy to clear.
5.4.2.4 magnesium sulfate solution was added dropwise in the test solution, i.e., a white precipitate.
5.5 Determination of Total Alkalinity
5.5.1 Method summary
Bromocresol green - methyl red mixed solution as the indicator solution, titration with hydrochloric acid standard solution titration.
5.5.2 Reagents
5.5.2.1 hydrochloric acid standard titration solution. Ba (HCl) about 1mol/L;
5.5.2.2 Bromocresol green - methyl red mixed indicator solution.
5.5.3 instruments and equipment
5.5.3.1 weighing bottle (30mm × 25mm) or porcelain crucible (capacity 30mL);
5.5.3.2 electric oven or high-temperature furnace. can be controlled at (250 ~ 270) ℃.
5.5.4 Analysis of step
5.5.4.1 Total Alkalinity (dry basis) of the Determination
Was weighed 1.7g (250 ~ 270) ℃ dried to a constant mass of sample, accurate to 0.0002g, set conical flask with
50mL water to dissolve the sample, add 10 drops of bromocresol green - methyl red mixed indicator solution, titration with hydrochloric acid standard solution titration solution from green to
Dark red, boiling 2min, cooled continue titration to dark red for the end. While doing the blank test.
5.5.4.2 Total Alkalinity (wet basis) Determination
Weigh 1.7g sample, accurate to 0.0002g, placed in a conical flask, dissolved in 50mL water, add 10 drops of bromocresol green - methyl red mixed
Indicator solution, titration with hydrochloric acid standard titration solution until the solution turns from green to dark red, boiling 2min, after cooling to continue titration to dark red
end. While doing the blank test.
5.5.5 Calculation Results
A total base amount of sodium carbonate (Na2CO3) mass fraction of 1 meter, expressed in%, according to equation (1).
1 = Ba
[(1- Vp Vp 0)/1000] M
(1)
Where.
Ba --- accurate hydrochloric acid standard titration solution concentration value in units of moles per liter (mol/L);
Hydrochloric acid standard titration value Vp 1 --- titration solution consumed by the sample solution volume in milliliters (mL);
Numerical hydrochloric acid standard titration V0 --- blank test solution titration solution consumed volume in milliliters (mL);
M --- sodium carbonate (12Na2CO3
) Numerical molar mass in grams per mole (g/mol) (M = 53.00).
Take the arithmetic mean of the parallel determination results of the measurement results, the results of parallel determination of the absolute difference is not more than 0.2%.
5.6 Determination of chloride content
5.6.1 potentiometric titration
5.6.1.1 Method summary
See GB/T 3050-2000 Chapter 2.
5.6.1.2 Reagents
5.6.1.2.1 nitrate solution. 1 + 1;
5.6.1.2.2 saturated solution of potassium nitrate;
5.6.1.2.3 bromophenol blue indicator solution. 1g/L ethanol solution;
5.6.1.2.4 chloride standard solution. Ba (NaCl) = 0.05mol/L;
Weigh 2.9225g in advance (500-600) ℃ drying to constant mass at baseline sodium chloride, accurate to 0.0002g, placed in a beaker
During and after the addition of water to dissolve all moved into 1000mL volumetric flask, add water to the mark.
5.6.1.2.5 standard silver nitrate titration solution. Ba (AgNO3) about 0.05mol/L;
a) preparation. Weigh 8.75g of silver nitrate, accurate to 0.01g, was dissolved in 1000mL of water, shake. Solution was kept in a brown bottle.
b) Calibration. Pipette Pipette 5mL sodium chloride standard solution, placed in 100mL beaker, add 40mL water, add EMS
Son, the beaker was placed on a magnetic stirrer, agitator, add 2 drops of bromophenol blue indicator solution, nitric acid solution was dropped to just yellow
color. The measuring electrode and reference electrode is inserted into the solution, connect potentiometer wiring, adjustment potentiometer zero potential recording start
value. Titration with standard silver nitrate titration solution, to join 4.00mL, then successively added 0.10mL. Record each addition of nitric acid
The total volume of the silver standard solution was titrated and the corresponding potential values E, calculated ΔE1 and increased successively increasing electrical potential value
ΔE2 difference between the bit values ΔE1. The titration is the maximum ΔE1 end, the end and then continue to record a potential value E.
Recording format, see GB/T 3050-2000 Appendix C.
Titration to the end of the consumption of the standard silver nitrate titration solution volume Vp (mL) according to equation (2).
Vp = Vp 1 Vp 0+ Chou B
(2)
Where.
V0 --- ΔE1 potential incremental value of the maximum value is added before the standard silver nitrate titration solution volume in milliliters (mL);
Vp 1 --- potential incremental value ΔE1 before last reached the maximum value added standard silver nitrate titration solution volume in milliliters
(ML of);
Chou --- ΔE2 last positive value;
B --- ΔE2 last positive and negative for the first time the absolute value of the sum.
c) Calculated. Ba concentration of the standard silver nitrate titration solution (AgNO3) the exact value (mol/L) according to equation (3) Calculated.
Ba Ba 2 Vp 2 Vp =
(3)
Where.
--- Accurate standard solution of sodium chloride concentration of Ba 2 value, in units of moles per liter (mol/L);
Numerical volume Vp 2 --- Pipette titration of sodium chloride standard solution, in milliliters (mL);
Value Vp --- titration consumption standard silver nitrate titration solution volume in milliliters (mL).
5.6.1.3 instruments and equipment
See GB/T 3050-2000 Chapter 5.
5.6.1.4 analysis step
Weigh about 1g sample, accurate to 0.01g, placed in 100mL beaker, add 40mL of water to dissolve. Following in 5.6.1.2.5
Carried out since the "Add electromagnetic stirrer" to start "before the end of a record potential value E" so far. But do not for the first time added
4.00mL standard silver nitrate titration solution. While doing the blank test.
5.6.1.5 Calculation Results
Chloride content of sodium chloride (NaCl) mass fraction 2 and its value is expressed in%, according to equation (4) Calculated.
Ba 2 =
[(Vp - Vp 0)/1000] M
100 (4)
Where.
Ba --- standard silver nitrate titration solution concentration accurate value of units of moles per liter (mol/L);
Value Vp --- titration consumption standard silver nitrate titration solution volume in milliliters (mL);
--- Blank test value V0 consumption standard silver nitrate titration solution volume in milliliters (mL);
0 --- measured by the loss on ignition of the mass fraction of the value of 6.9, in%;
Numerical --- the M NaCl (NaCl) molar mass in grams per mole (g/mol) (M = 58.44).
Take the arithmetic mean of the parallel determination results of the measurement results, the results of parallel determination of the absolute difference is not more than 0.02%.
5.6.2 Mercury Method (Arbitration Act)
5.6.2.1 Method summary
See Chapter 3 GB 3051-2000.
5.6.2.2 Reagents and materials
5.6.2.2.1 nitrate solution. 1 + 1;
5.6.2.2.2 nitrate solution. 1 + 7;
5.6.2.2.3 sodium hydroxide solution. 40g/L;
5.6.2.2.4 nitrate mercury standard titration solution. c [1/2Hg (NO3) 2 · H2O] is about 0.05mol/L.
5.6.2.2.5 bromophenol blue indicator solution. 1g/L
5.6.2.2.6 diphenylcarbazone hydrazine indicator solution. 5g/L.
5.6.2.3 instruments and equipment
Buret. indexing is 0.01mL.
5.6.2.4 analysis step
5.6.2.4.1 Preparation of the solution than the Senate
In 250mL Erlenmeyer flask was added 40mL of water and 2 drops of bromophenol blue indicator solution. Solution of nitric acid solution (5.6.2.2.1) to the solution from blue
Just change the color yellow, and then an excess (2-3) drops. Join 1mL diphenylcarbazone hydrazine indicator solution, titration with mercury nitrate standard solution titration solution
From yellow to purple, record volume of mercury nitrate titration standard solution used. This solution was prepared prior to use.
5.6.2.4.2 Determination of the sample
Weigh about 2g specimen to the nearest 0.01g, placed in 250mL conical flask, add water to dissolve 40mL, add 2 drops of bromophenol blue indicator solution,
Solution of nitric acid solution (5.6.2.2.1) and to yellow, then dropping sodium hydroxide solution to the blue, then the nitric acid solution (5.6.2.2.2) tune
Just to yellow and then an excess (2-3) drops, added 1mL diphenylcarbazone hydrazine indicator solution, titration with mercury nitrate standard solution was titrated from yellow to
Becomes the reference solution the same purple is the end.
Save the mercury-containing waste after titration up, according to GB 3051-2000 Annex D for processing.
5.6.2.5 Calculation Results
Chloride content of sodium chloride (NaCl) mass fraction 2 and its value is expressed in%, according to equation (5) Calculated.
Ba 2 =
[(Vp - Vp 0)/1000] M
100 (5)
Where.
Accurate Ba --- mercuric nitrate standard titration solution concentration value in units of moles per liter (mol/L);
--- Titration value Vp consumed mercury nitrate standard titration solution volume in milliliters (mL);
V0 --- reference volume mercuric nitrate titration solution than the standard preparation solution consumed value in milliliters (mL);
0 --- measured by the loss on ignition of the mass fraction of the value of 6.9, in%;
Numerical --- the M NaCl (NaCl) molar mass in grams per mole (g/mol) (M = 58.44).
Take the arithmetic mean of the parallel determination results of the measurement results, the results of parallel determination of the absolute difference is not more than 0.02%.
5.7 Determination of iron content
5.7.1 Method summary
With GB/T 3049-2006 Chapter 3.
5.7.2 Reagents
With GB/T 3049-2006 Chapter 4.
5.7.3 instruments and equipment
See GB/T 3049-2006 Chapter 5.
5.7.4 Analysis of step
5.7.4.1 Preparation of test solution
It weighs about 10g sample, accurate to 0.01g, beaker, add a little water wet, covered with a watch glass, dropping 35mL hydrochloric acid solution
(1 + 1), boiled (3 ~ 5) min. Cooling (if necessary filtering) all transferred to 250mL volumetric flask, dilute to the mark, shake.
5.7.4.2 Preparation of the blank test solution
Measure 7mL hydrochloric acid solution (1 + 1), placed in 100mL beaker, dropping ammonia solution (2 + 3) to neutral (pH test precision
Paper test).
5.7.4.3 Draw the curve
See GB/T 3049-2006 Chapter 6.3. Select (4 or 5) cm absorption cell and the corresponding standard iron solution volume.
5.7.4.4 Determination
Pipette with a pipette 50mL test solution and the blank test solution 50mL with aqueous ammonia solution (1 + 8), respectively, or hydrochloric acid
(1 + 3) was adjusted to a pH of about 2 (with a precision pH test paper). All were transferred to 100mL volumetric flask. Following in the
GB/T 3049-2006 Chapter 6.4 absorbance measurement. Measuring the absorbance of the test solution and blank solution.
5.7.5 Calculation Results
Iron content of iron (Fe) mass fraction 3 and its value is expressed in%, according to equation (6) Calculated.
3 =
× 100 (6)
Where.
0 --- measured by the loss on ignition of the mass fraction of the value of 6.9, in%.
Take the arithmetic mean of the parallel determination results of the measurement results, the results of parallel determination of the absolute difference is not more than 0.0005%.
5.8 Determination of Heavy Metal Content
5.8.1 Method summary
Under weakly acidic (pH 3 to 4) conditions, heavy metal ions in the sample and the role of hydrogen sulfide to produce brown-black, with the same treatment of
Comparison of lead standard solution.
5.8.2 Reagents
5.8.2.1 hydrochloric acid solution. 1 + 4;
5.8.2.2 ammonia solution. 1 + 2;
5.8.2.3 glacial acetic acid. 1 + 15;
5.8.2.4 sodium sulfide or hydrogen sulfide solution solution;
5.8.2.5 Lead standard solution. 1mL lead (Pb) 0.010mg, Extemporaneous;
Pipette Pipette 10mL lead standard solution according to HG/T 3696.2 prepared, placed in 100mL volumetric flask, dilute to the mark with water
Degree, shake.
5.8.2.6 phenolphthalein indicator solution. 10g/L.
5.8.3 Analysis of step
5.8.3.1 Preparation of test solution
Weigh (2.00 ± 0.01) g sample was placed in 100mL beaker, add 5mL water, cover the surface of the dish by slowly added 17mL cup salt
Acid solution, boiled for 5min, add 1 drop of phenolphthalein indicator solution was cooled with aqueous ammonia solution to a red light and.
All transferred 50mL colorimetric tube, add 2mL acetic acid solution, 10mL solution of sodium sulfide or hydrogen sulfide solution, add water to the mark.
Place after 10min in the dark and relatively standard, it shall not be deeper than the standard.
5.8.3.2 Preparation of the solution than the standard
Standard with a pipette of 2mL lead standard solution, placed in 100mL beaker. 5.8.3.1 The following from "plus 5mL
Water "and start the test solution at the same time in the same manner.
5.9 Determination of Arsenic
Weigh 1.00g ± 0.01g sample was placed in a conical flask, wetted with water, neutralized with hydrochloric acid to neutral (pH paper test with), and then the excess
5mL, shake. Pipette with a pipette 2mL arsenic standard solution (a solution containing ImL 1μgAs) as a standard, placed in another conical flask
in. Each 5mL was added hydrochloric acid solution (1 + 3). And then follow the GB/T 5009.76─2003 first law silver diethyl dithiocarbamate
6.2 Limited colorimetric test instructions or follow the GB/T 5009.76─2003 second method Gutzeit method 11 Determination.
Diethyl dithiocarbamate silver arbitration colorimetric method.
5.10 Burning Determination of loss
5.10.1 Method summary
Sample at (250 ~ 270) ℃ heated to a constant mass. Loss of free water and sodium bicarbonate by the decomposition of water and dioxide when heated
Carbon, calculated the loss on ignition.
5.10.2 instruments and equipment
5.10.2.1 weighing bottle. 30mm × 25mm or porcelain crucible capacity 30mL;
5.10.2.2 electric oven or high-temperature furnace, can be controlled at (250 ~ 270) ℃.
5.10.3 analysis step
In advance at (250 ~ 270) ℃ dried to constant mass weighing bottles or porcelain crucible Weigh about 2g sample, accurate to 0.0002g,
Placed in a high temperature oven or electric oven at (250 ~ 270) ℃ heated to a constant mass.
5.10.4 Calculation Results
Loss on ignition mass fraction 0 and its value is expressed in%, according to equation (7) Calculated.
(7)
Where.
Take the arithmetic mean of the parallel determination results of the measurement results, the results of parallel determination of the absolute difference is not more than 0.04%.
5.11 Determination of water-insoluble matter content
5.11.1 Method summary
Samples were dissolved in (50 ± 5) ℃ water, the insoluble was filtered, washed with, dried and weighed.
5.11.2 Reagents and materials
5.11.2.1 hydrochloric acid solution. 1 + 3;
5.11.2.2 Anhydrous sodium carbonate solution. 100g/L;
5.11.2.3 phenolphthalein solution. 10g/L;
5.11.2.4 Pickling asbestos;
Acid appropriate amount of asbestos in a beaker, was added a solution of hydrochloric acid, boiled 20min, filtered through a Buchner funnel and washed until neutral. Remove soaked
In sodium carbonate solution and boiled 20min, filtered through a Buchner funnel and washed with water to neutral (phenolphthalein test solution), remove the beaker plus
Water into a paste and set aside.
5.11.2.5 asbestos filter paper.
5.11.3 instruments and equipment
5.11.3.1 Gooch crucible. Capacity 30mL;
5.11.3.2 electric oven. it can be controlled at (110 ± 5) ℃.
5.11.4 analysis step
5.11.4.1 Gooch crucible shop system
5.11.4.1.1 pickling asbestos Gooch crucible method (Arbitration Act)
The Gooch crucible filtration bottle placed on the sieve up and down the uniform layer of pickled asbestos, while suction side pressed with a flathead glass rod, each
Thickness of 3mm. With (50 ± 5) ℃ washed with water until the filtrate does not contain asbestos fibers. The Gooch crucible placed in an electric oven at (110 ± 5) ℃ under
After drying weighed repeatedly washed, dried to a constant mass.
5.11.4.1.2 asbestos paper Gooch crucible method
The Gooch crucible filtration bottle placed on the lower berth layer of asbestos paper sieve, sieve capped at two asbestos filter, suction side edge with a flat head
Pressed glass rod. With (50 ± 5) ℃ water washed filter paper. The Gooch crucible placed in an electric oven at (110 ± 5) ℃ after drying weighed repeat
Washed, dried to a constant mass.
5.11.4.2 Determination
Weigh about 40g specimen to the nearest 0.01g, placed in a beaker, was added 400mL of water about 40 ℃ dissolved, the solution was maintained at
(50 ± 5) ℃. Use has been constant quality Gooch crucible filtration, washed with (50 ± 5) ℃ water until take 20mL filtrate add 2 drops of phenolphthalein after not
Until the red color, wash water control total volume of 800mL. Remove Gooch crucible placed (110 ± 5) ℃ electric oven dried to a constant mass.
5.11.5 Calculation Results
Water-insoluble content of 4 and its value is expressed in%, according to equation (8) Calculated.
100 (8)
Where.
0 --- 6.9 measured by value loss on ignition of the mass fraction, expressed in%.
Take the arithmetic mean of the parallel determination results of the measurement results, the results of parallel determination of the absolute difference is not more than 0.006%.
6 Inspection rules
6.1 All items are standard factory inspection items should test batch.
6.2 Manufacturer of the same material, the same basic production conditions, continuous production of sodium a day of food additive batch.
6.3 determine the sampling units according to GB/T 6678 provisions. Sampling, the sampler from the center of the bag is......
......
|