1 Scope
This standard specifies the determinative method of total volatile basic nitrogen (TVBN) in foods.
This standard is applicable to the determination of TVBN in foods mainly made of meat, fresh (frozen) meat of animals, meat products and prepared meat products, animal aquatic products and seafood products and their prepared products, preserved egg products such as preserved eggs (century eggs) and salted eggs.
Method I Semimicro-kjeldahl determination
2 Principle
TVBN includes alkaline nitrogenous substances, such as ammonia and amines, produced by the decomposition of protein in animal food due to the action of enzymes and bacteria. Since its volatility, TVBN is evaporated in alkaline solution, absorbed by boric acid solution, and titrated with standard acid solution to calculate its content.
3 Reagents and materials
Unless otherwise specified, analytically-pure reagents and Class-III water (defined in GB/T 6682) are adopted for the purpose of this method.
3.1 Reagents
3.1.1 Magnesium oxide (MgO).
3.1.2 Boric acid (H3BO3).
3.1.3 Trichloroacetic acid (C2HCl3O2).
3.1.4 Hydrochloric acid (HCl) or sulfuric acid (H2SO4).
3.1.5 Methyl red indicator (C15H15N3O2)。
3.1.6 Bromocresol green indicator (C21H14Br4O5S) or methylene blue indicator (C16H18ClN3S•3H2O).
3.1.7 95% ethanol (C2H5OH).
3.1.8 Silicon oil defoamer.
3.2 Preparation of reagents
3.2.1 Magnesium oxide suspension (10g/L): weigh 10g of magnesium oxide, add 1,000mL of water and shake them into suspension.
3.2.2 Boric acid solution (20g/L): weigh 20g of boric acid, add water to dissolve it and then dilute to 1,000mL.
3.2.3 Trichloroacetic acid solution (20g/L): weigh 20g of trichloroacetic acid, add water to dissolve it and then dilute to 1,000mL.
3.2.4 Hydrochloric acid standard volumetric solution (0.1000mol/L) or sulfuric acid standard volumetric solution (0.1000mol/L): prepared in accordance with GB/T 601.
3.2.5 Hydrochloric acid standard volumetric solution (0.0100mol/L) or sulfuric acid standard volumetric solution (0.0100mol/L): prepared with hydrochloric acid standard volumetric solution (0.1000mol/L) or sulfuric acid standard volumetric solution (0.1000mol/L) before use.
3.2.6 Methyl red ethanol solution (1g/L): weigh 0.1g of methyl red, dissolve it in 95% ethanol and then dilute to 100mL with 95% ethanol.
3.2.7 Bromocresol green ethanol solution (1g/L): weigh 0.1g of bromocresol green, dissolve it in 95% ethanol and then dilute to 100mL with 95% ethanol.
3.2.8 Methylene blue ethanol solution (1g/L): weigh 0.1g of methylene blue and dissolve it in 95% ethanol and then dilute to 100mL with 95% ethanol.
3.2.9 Mixed indicator solution: mix 1 part of methyl red ethanol solution and 5 parts of bromocresol green ethanol solution for immediate use, or 2 parts of methyl red ethanol solution and 1 part of methylene blue ethanol solution for immediate use.
Foreword I
1 Scope
2 Principle
3 Reagents and materials
4 Apparatus
5 Analysis procedures
6 Expression of analysis results
7 Precision
8 Reagents and materials
9 Apparatus
10 Analysis procedures
11 Expression of analysis results
12 Precision
13 Principle
14 Reagents and materials
15 Apparatus
16 Analysis procedures
17 Expression of analysis results
18 Precision
19 Detection limit
Annex A Diagram of semimicro nitrogen determination and distillation device
Standard
GB 5009.228-2016 National Food Safety Standard - Determination of Volatile Basic Nitrogen in Food (English Version)
Standard No.
GB 5009.228-2016
Status
valid
Language
English
File Format
PDF
Word Count
4500 words
Price(USD)
120.0
Implemented on
2017-3-1
Delivery
via email in 1 business day
Detail of GB 5009.228-2016
Standard No.
GB 5009.228-2016
English Name
National Food Safety Standard - Determination of Volatile Basic Nitrogen in Food
1 Scope
This standard specifies the determinative method of total volatile basic nitrogen (TVBN) in foods.
This standard is applicable to the determination of TVBN in foods mainly made of meat, fresh (frozen) meat of animals, meat products and prepared meat products, animal aquatic products and seafood products and their prepared products, preserved egg products such as preserved eggs (century eggs) and salted eggs.
Method I Semimicro-kjeldahl determination
2 Principle
TVBN includes alkaline nitrogenous substances, such as ammonia and amines, produced by the decomposition of protein in animal food due to the action of enzymes and bacteria. Since its volatility, TVBN is evaporated in alkaline solution, absorbed by boric acid solution, and titrated with standard acid solution to calculate its content.
3 Reagents and materials
Unless otherwise specified, analytically-pure reagents and Class-III water (defined in GB/T 6682) are adopted for the purpose of this method.
3.1 Reagents
3.1.1 Magnesium oxide (MgO).
3.1.2 Boric acid (H3BO3).
3.1.3 Trichloroacetic acid (C2HCl3O2).
3.1.4 Hydrochloric acid (HCl) or sulfuric acid (H2SO4).
3.1.5 Methyl red indicator (C15H15N3O2)。
3.1.6 Bromocresol green indicator (C21H14Br4O5S) or methylene blue indicator (C16H18ClN3S•3H2O).
3.1.7 95% ethanol (C2H5OH).
3.1.8 Silicon oil defoamer.
3.2 Preparation of reagents
3.2.1 Magnesium oxide suspension (10g/L): weigh 10g of magnesium oxide, add 1,000mL of water and shake them into suspension.
3.2.2 Boric acid solution (20g/L): weigh 20g of boric acid, add water to dissolve it and then dilute to 1,000mL.
3.2.3 Trichloroacetic acid solution (20g/L): weigh 20g of trichloroacetic acid, add water to dissolve it and then dilute to 1,000mL.
3.2.4 Hydrochloric acid standard volumetric solution (0.1000mol/L) or sulfuric acid standard volumetric solution (0.1000mol/L): prepared in accordance with GB/T 601.
3.2.5 Hydrochloric acid standard volumetric solution (0.0100mol/L) or sulfuric acid standard volumetric solution (0.0100mol/L): prepared with hydrochloric acid standard volumetric solution (0.1000mol/L) or sulfuric acid standard volumetric solution (0.1000mol/L) before use.
3.2.6 Methyl red ethanol solution (1g/L): weigh 0.1g of methyl red, dissolve it in 95% ethanol and then dilute to 100mL with 95% ethanol.
3.2.7 Bromocresol green ethanol solution (1g/L): weigh 0.1g of bromocresol green, dissolve it in 95% ethanol and then dilute to 100mL with 95% ethanol.
3.2.8 Methylene blue ethanol solution (1g/L): weigh 0.1g of methylene blue and dissolve it in 95% ethanol and then dilute to 100mL with 95% ethanol.
3.2.9 Mixed indicator solution: mix 1 part of methyl red ethanol solution and 5 parts of bromocresol green ethanol solution for immediate use, or 2 parts of methyl red ethanol solution and 1 part of methylene blue ethanol solution for immediate use.
Contents of GB 5009.228-2016
Foreword I
1 Scope
2 Principle
3 Reagents and materials
4 Apparatus
5 Analysis procedures
6 Expression of analysis results
7 Precision
8 Reagents and materials
9 Apparatus
10 Analysis procedures
11 Expression of analysis results
12 Precision
13 Principle
14 Reagents and materials
15 Apparatus
16 Analysis procedures
17 Expression of analysis results
18 Precision
19 Detection limit
Annex A Diagram of semimicro nitrogen determination and distillation device