GB 5009.33-2025 (GB 5009.33-2016) PDF English
US$115.00 · In stock · Download in 9 secondsGB 5009.33-2016: National food safety standard - Determination of Nitrite and Nitrate in Foods Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedureStatus: Valid GB 5009.33: Evolution and historical versions
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivery | Name of Chinese Standard | Status |
| GB 5009.33-2025 | English | 439 |
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National food safety standard - Determination of nitrite and nitrate in foods
| Valid |
| GB 5009.33-2016 | English | 115 |
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National food safety standard - Determination of Nitrite and Nitrate in Foods
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| GB 5009.33-2010 | English | 85 |
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National food safety standard -- Determination of nitrite and nitrate in foods
| Obsolete |
| GB/T 5009.33-2008 | English | 479 |
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Determination of nitrite and nitrate in foods
| Obsolete |
| GB/T 5009.33-2003 | English | 319 |
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Determination of nitrite and nitrate in foods
| Obsolete |
| GB/T 5009.33-1996 | English | 239 |
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Method for determination of nitrite and nitrate in foods
| Obsolete |
| GB 5009.33-1985 | English | 199 |
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Method for determination of nitrite and nitrate in foods
| Obsolete |
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GB 5009.33-2016: National food safety standard - Determination of Nitrite and Nitrate in Foods---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GB5009.33-2016
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard -
Determination of Nitrite and Nitrate in Foods
Issued on. DECEMBER 23, 2016
Implemented on. JUNE 23, 2017
Issued by. National Health and Family Planning Commission of the
People’s Republic of China;
State Food and Drug Administration of the People’s Republic
of China.
Table of Contents
Foreword... 3
1 Scope... 4
Method I Ion Chromatography... 4
2 Principle... 4
3 Reagents and Materials... 4
4 Instruments and Equipment... 5
5 Analytical Procedures... 6
6 Expression of Analysis Results... 8
7 Precision... 9
8 Others... 9
Method II Spectrophotometry... 9
9 Principle... 9
10 Reagents and Materials... 10
11 Instruments and Equipment... 12
12 Analytical Procedures... 15
13 Expression of Analysis Results... 17
14 Precision... 18
15 Others... 18
Method III Determination of Nitrate in Vegetables and Fruits - UV
Spectrophotometry... 18
16 Principle... 18
17 Reagents and Materials... 19
18 Instruments and Equipment... 20
19 Analytical Procedures... 20
20 Calculation Result... 21
21 Precision... 21
22 Others... 21
Appendix A Chromatogram of Nitrite and Nitrate... 22
Foreword
This Standard is drafted as a replacement of GB 5009.33-2010 “National Food Safety
Standard - Determination of Nitrite and Nitrate in Foods”, NY/T 1375-2007
“Determination of Nitrite and Nitrate in Plant Product - Ion Chromatography Method”,
NY/T 1279-2007 “Determination of Nitrate in Vegetables and Fruits - UV
Spectrophotometry”, and SN/T 3151-2012 “Determination of Nitrite and Nitrate in
Export Foods - Ion Chromatography Method”.
In comparison with GB 5009.33-2010, there are several main modifications as follows.
-- Previous Method II and Method III are combined into Method II;
-- The method of UV spectrophotometry is added to the determination of nitrate in
vegetables and fruits.
National Food Safety Standard -
Determination of Nitrite and Nitrate in Foods
1 Scope
This Standard specifies the method of determining nitrite and nitrate in foods.
This Standard is applicable to the determination of nitrite and nitrate in foods.
Method I -- Ion Chromatography
2 Principle
Precipitate protein and remove fat from the sample; adopt the corresponding method
to extract and purify; take potassium hydroxide solution as the eluent; adopt anion
exchange column for separation; take conductance detector or UV detector for
detection. Determine the nature with the retention time and quantify with the external
standard method.
3 Reagents and Materials
Unless otherwise indicated, the reagents adopted under this method are of analytical
purity. The water is first-grade water as specified in GB/T 6682.
3.1 Reagents
3.2 Preparation of Reagents
3.2.1 Acetic acid solution (3%). weigh-take 3 mL of acetic acid, place it in 100 mL
volumetric flask. Add water to dilute to the constant volume; mix it up.
3.2.2 Potassium hydroxide solution (1 mol/L). weigh-take 6 g of potassium hydroxide;
dissolve it in cold water that’s newly boiled; dilute to 100 mL; mix it up.
3.3 Standards
3.4 Preparation of Standard Solutions
3.4.1 Standard stock solution of nitrite (100 mg/L, calculated by NO2-, same as below).
accurately weigh-take 0.1500 g of sodium nitrite that’s dried to constant weight under
110 °C~120 °C. Add water to dissolve it; transfer it to 1,000 mL volumetric flask.
3.4.2 Standard stock solution of nitrate (1,000 mg/L, calculated by NO3-, same as
below).
3.4.3 Standard mixed intermediate solution of nitrite and nitrate. accurately
remove-take 1.0 mL of standard stock solution of nitrite ion (NO2-) and 1.0 mL of
standard stock solution of nitrate ion (NO3-); place it in 100 mL volumetric flask.
4 Instruments and Equipment
4.1 Ion chromatograph. equipped with conductance detector and suppressor, or UV
detector, high-capacity anion exchange column, 50 μL quantitative cup.
4.2 Food grinder.
4.4 Analytical balance. division value. 0.1 mg and 1 mg.
4.5 Centrifuge. rotating speed ≥10,000 r/min, equipped with 50 mL centrifuge tube.
4.6 0.22 μm water filter needle filter.
4.7 Purification column. include C18 column, Ag column and Na column or equivalent
column.
5 Analytical Procedures
5.1 Pre-processing of Samples
5.2 Extraction
5.2.1 Plant samples, such as vegetable and fruit. weigh-take 5 g (accurate to 0.001 g,
the weight can be properly adjusted, same as below) of sample; place it in 150 mL
conical flask with a plug; add 80 mL of water, 1 mL of 1 mol/L potassium hydroxide
solution.
5.2.5 Milk powder and cottage cheese. weigh-take 2.5 g (accurate to 0.01 g) of
sample, place it in 100 mL conical flask with a plug; add 80 mL of water, mix it up. Start
ultrasonic extraction for 30 min. Take it out and wait till it reaches the room
temperature. Quantitatively transfer it into 100 mL volumetric flask; add 2 mL of 3%
acetic acid solution. Add water to dilute to the constant volume. Place it under 4 °C for
20 min; take it out and wait till it reaches the room temperature. Use filter paper to filter
the solution; reserve the filtrate for later usage.
5.3 Instrument Reference Conditions
5.3.1 Chromatographic column. hydroxide selectivity, divinylbenzene-ethyl styrene
copolymer matrix that’s compatible with gradient elution, high-capacity anion
exchange column of alkyl quaternary ammonium salt functional group, 4 mm x 250
mm (with guard column 4 mm x 50 mm), or ion chromatographic column with
equivalent performance.
5.3.2 Eluent
5.3.2.1 Potassium hydroxide solution, concentration. 6 mmo/L~70 mmol/L; elution
gradient. 6 mmol/L 30 min, 70 mmol/L 5 min, 6 mmol/L 5 min; flow rate. 1.0 mL/min.
5.4 Determination
5.4.1 Standard Curve
Inject the standard series of working fluid into ion chromatograph respectively; obtain
the chromatogram of the standard series of working fluid under different concentration;
determine corresponding peak height (μS) or peak area; take the concentration of the
standard series of working fluid as x-coordinate, and peak height (μS) or peak area as
y-coordinate.
5.4.2 Determination of Sample Solution
Inject blank solution and sample solution into ion chromatograph; obtain the peak
height (μS) or peak area of blank solution and sample solution. Obtain the
concentration of nitrite ion or nitrate ion in the test solution in accordance with the
standard curve.
6 Expression of Analysis Results
The content of nitrite ion or nitrate ion in the sample shall be calculated in accordance
with Formula (1).
7 Precision
The absolute difference between the two independent determination results obtained
under repeatability conditions shall not exceed 10% of the arithmetic mean value.
8 Others
The detection limit of nitrite and nitrate is 0.2 mg/kg and 0.4 mg/kg respectively in
Method I.
9 Principle
Adopt naphthalene ethylenediamine hydrochloride method to determine nitrite; adopt
cadmium column reduction method to determine nitrate.
10 Reagents and Materials
Unless otherwise indicated, the reagents adopted under this method are of analytical
purity. The water is first-grade water as specified in GB/T 6682.
10.1 Reagents
10.2 Preparation of Reagents
10.3 Standards
10.3.1 Sodium nitrite (NaNO2, CAS No.. 7632-00-0). reference reagents, or standard
nitrite solution supported by Reference Material Certificate.
3.3.2 Sodium nitrate (NaNO3, CAS No.. 7631-99-4). reference reagents, or standard
nitrate solution supported by Reference Material Certificate.
10.4 Preparation of Standard Solutions
10.4.1 Standard solution of sodium nitrite (200 μg/mL, calculated by sodium nitrite).
accurately weigh-take 0.1000 g of sodium nitrite that’s dried to constant weight under
110 °C~120 °C. Add water to dissolve it; transfer it to 500 mL volumetric flask. Add
water to dilute to the constant volume; mix it up.
10.4.4 Standard working solution of sodium nitrate (5.0 μg/mL, calculated by sodium
nitrite). before usage, extract 2.50 mL of standard solution of sodium nitrate; place it in
100 mL volumetric flask. Add water to dilute to the constant volume.
......
Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al.
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