GB 1886.350-2021 PDF in English
GB 1886.350-2021 (GB1886.350-2021) PDF English
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National Food Safety Standard - Food Additives - Nitrous Oxide
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Standards related to (historical): GB 1886.350-2021
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GB 1886.350-2021: PDF in English GB 1886.350-2021
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard - Food Additives -
Nitrous Oxide
ISSUED ON: SEPTEMBER 07, 2021
IMPLEMENTED ON: MARCH 07, 2022
Issued by: National Health Commission;
State Administration for Market Regulation.
Table of Contents
1 Scope ... 3
2 Chemical name, molecular formula, structural formula and relative molecular
mass ... 3
3 Technical requirements ... 3
Annex A Inspection methods ... 5
National Food Safety Standard - Food Additives -
Nitrous Oxide
1 Scope
This Standard applies to nitrous oxide, a food additive obtained by thermal
decomposition using ammonium nitrate as a raw material.
2 Chemical name, molecular formula, structural
formula and relative molecular mass
2.1 Chemical name
Nitrous oxide (nitrous oxide).
2.2 Molecular formula
N2O
2.3 Structural formula
N-N-O
2.4 Relative molecular mass
44.01 (according to 2018 international relative atomic mass)
3 Technical requirements
3.1 Sensory requirements
Sensory requirements shall meet the requirements of Table 1.
Annex A
Inspection methods
WARNING: Some procedures specified in the test method may lead to
dangerous situations. The operator shall take appropriate safety and
protective measures. During the test, there shall be nitrous oxide tail gas
treatment measures.
A.1 General
The reagents and water used in this Standard refer to analytically-pure reagents
and grade 3 water specified in GB/T 6682 when other requirements are not
indicated. The solution used in the test refers to an aqueous solution when it is
not specified which solvent is used to prepare it.
A.2 Identification test
A.2.1 Method principle
Nitrous oxide can make red wood sticks ignite and burn. But when it passes
into alkaline pyrogallic acid solution, the solution will not turn brown.
A.2.2 Reagents and materials
A.2.2.1 Wooden sticks.
A.2.2.2 Pyrogallic acid (1,2,3-pyrogallol).
A.2.2.3 Potassium hydroxide.
A.2.2.4 Alkaline pyrogallic acid solution: Take 0.5g of pyrogallic acid (1,2,3-
pyrogallol). Add 2mL of water to dissolve. Shake well to obtain solution A. Take
12g of potassium hydroxide. Add 8mL of water to dissolve. Shake well to obtain
solution B (saturated potassium hydroxide solution). Mix the two solutions A and
B immediately before use. It shall be prepared in a vacuum glove box.
A.2.3 Instruments and equipment
Vacuum glove box.
A.2.4 Analysis steps
A.2.4.1 Connect the sample gas to the gas pressure reducing valve. Open the
valve. Pour gas into a clean reagent bottle. Close the gas sampling valve.
Quickly cover the reagent bottle with a watch glass. Then put the red wood
sticks into the reagent bottle containing nitrous oxide gas. Wooden sticks can
A.5.2 Reagents and materials
A.5.2.1 Chromatographic carrier gas: High-purity helium gas, whose purity
should be greater than 99.999%.
A.5.2.2 Standard sample: Use helium with a purity greater than 99.9999% as
the bottom gas. The oxygen content (volume fraction) is 0.2%, and the nitrogen
content (volume fraction) is 0.8%.
A.5.3 Instruments and equipment
Gas chromatograph: Equipped with thermal conductivity detector.
A.5.4 Reference chromatographic conditions
A.5.4.1 Chromatographic column: Stainless steel tube with a length of about
1.5m and an inner diameter of 2mm, with a 13X molecular sieve with a particle
size of 0.25mm~0.4mm, or other equivalent chromatographic columns.
A.5.4.2 Carrier gas flow (He>99.999%): 10mL/min.
A.5.4.3 Detector temperature: 160°C.
A.5.4.4 Oven temperature: 30°C.
A.5.4.5 Makeup gas flow rate: 5.0mL/min.
A.5.5 Determination steps
A.5.5.1 Preparation
Turn on the instrument according to the instrument manual. Set various
operating parameters of the instrument until the instrument works normally.
A.5.5.2 Calibration
Connect the standard sample to the instrument through the sampling tube. Turn
on the sample to fully purge the sampling system until a representative sample
is obtained. Switch the sampling valve to inject samples into the instrument.
Measure the response value of the instrument (peak area or peak height).
Repeat the injection at least 2 times, until the relative deviation of the response
value is less than 5%. Take the average value As.
A.5.5.3 Determination
Perform under exactly the same conditions as the calibration. Connect the
sample gas to the instrument through the sampling tube. Turn on the sample to
fully purge the sampling system until a representative sample is obtained.
Switch the sampling valve to inject samples into the instrument. Measure the
A.7 Determination of ammonia
A.7.1 Method principle
When a certain amount of gas passes through the detection tube, the measured
gas in the gas sample is adsorbed on the surface of the indicator powder by
diffusion and chemically reacts with the color-generating chemical reagents to
cause the indicator powder to change color. The concentration of the measured
gas in the gas is different. The length of the color-changing column is also
different.
A.7.2 Reagents and materials
Ammonia detection tube: The volume fraction of the measuring range is 1×10-
6~30×10-6, or other suitable measuring ranges.
A.7.3 Analysis steps
The measurement starts when the nitrous oxide gas is injected into the
detection tube. The control of injection volume, injection flow and color change
are carried out in accordance with the operating instructions of the detection
tube. According to the length of the color change of the detection tube, the
ammonia content is obtained.
A.8 Determination of nitric oxide and nitrogen dioxide
A.8.1 Test tube method
A.8.1.1 Method principle
When a certain amount of gas passes through the detection tube, the measured
gas in the gas sample is adsorbed on the surface of the indicator powder by
diffusion and chemically reacts with the color-generating chemical reagents to
cause the indicator powder to change color. The concentration of the measured
gas in the gas is different. The length of the color-changing column is also
different.
A.8.1.2 Instruments and equipment
Nitrogen oxide detection tube: Volume fraction of the measuring range is
0.2×10-6~5×10-6, or other suitable measuring ranges.
A.8.1.3 Analysis steps
The measurement starts when the nitrous oxide gas is injected into the
detection tube. The control of injection volume, injection flow and color change
are carried out in accordance with the operating instructions of the detection
tube. According to the length of the color change of the detection tube, the total
...... Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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