GB 5009.4-2016 (GB5009.4-2016) & related versions
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GB 5009.4-2016
GB
NATIONAL STANDARD OF
THE PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard -
Determination of Ash in Foods
ISSUED ON. AUGUST 31, 2016
IMPLEMENTED ON. MARCH 1, 2017
Issued by. National Health and Family Planning Commission of the
People 's Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Principle... 4
3 Reagents and materials ... 4
4 Instruments and equipment ... 5
5 Analysis steps ... 5
6 Expression of analysis results ... 7
7 Precision... 9
8 Principle... 9
9 Reagents and materials ... 9
10 Instruments and equipment ... 9
11 Analysis steps ... 10
12 Expression of analysis results ... 10
13 Precision ... 12
14 Principle... 12
15 Reagents and materials... 13
16 Instruments and equipment ... 13
17 Analysis steps ... 13
18 Expression of analysis results ... 14
19 Precision ... 15
Foreword
This Standard replaces GB 5009.4-2010 Determination of Ash in Foods,
GB/T 5505-2008 Inspection of grain and oils - Determination of the ash
content by incineration, GB/T 22427.1-2008 Starch - Determination of ash,
GB/T 9695.18-2008 Meat and meat products - Determination of total ash,
GB/T 12532-2008 Determination of ash content in edible mushroom, GB/T
9824-2008 Determination of total ash in oilseed residues, GB/T 9825-2008
Inspection of grain and oils - Determination of insoluble dietary fiber in cereals,
GB/T 12729.7-2008 Spices and condiments - Determination of total ash,
GB/T 12729.8-2008 Spices and condiments - Determination of
water-insoluble ash, GB/T 12729.9-2008 Spices and condiments -
Determination of acid-insoluble ash, GB/T 17375-2008 Animal and vegetable
fats and oils - Determination of ash, GB/T 22510-2008 Cereals, pulses and
by-products - Determination of ash yield by incineration, GB/T 8306-2013 Tea
- Determination of Total Ash Content, GB/T 8307-2013 Tea - Determination of
Water-soluble Ash and Water-insoluble Ash Content, GB/T 8308-2013 Tea -
Determination of Acid-insoluble Ash Content, SN/T 0925-2000 Method for the
determination of tea total ash of for import and export, SN/T 0921-2000
Method for the determination of water-soluble ash and water-insoluble ash of
tea for import and export, SN/T 0923-2000 Method for the determination of
acid-insoluble ash of tea for import and export, NY 82.8-1988 Determination
of Fruit Juice - Total Ash.
Compared with GB 5009.4-2010, the main modifications in this Standard are
as follows.
- added the determination of ash in starch and its derivatives according to
GB/T 22427.1-2008;
- added the determinations of water-soluble ash and water-insoluble ash,
the determinations of acid soluble ash and acid insoluble ash in some
foods.
National Food Safety Standard -
Determination of Ash in Foods
1 Scope
Method One of this Standard specifies the determination method of ash in
foods. Method Two specifies the determination method of water-soluble ash
and water-insoluble ash in foods. Method Three specifies the determination
method of acid insoluble ash in foods.
Method One of this Standard is applicable to the determination of ash in foods
(starch ash method is applicable to starch and modified starch of which the
mass fraction is not greater than 2%). Method Two is applicable to the
determinations of water-soluble ash and water-insoluble ash in foods. Method
Three is applicable to the determination of acid insoluble ash in foods.
Method One Determination of total ash in foods
2 Principle
The inorganic matter left after the burning of the food is called ash. Ash value
is calculated by burning and weighing.
3 Reagents and materials
Unless otherwise stated, the reagents used in this method are of analytical
grade and water is Grade 3 water specified in GB/T 6682.
3.1 Reagents
3.1.1 Magnesium acetate [(CH3COO)2Mg•4H2O]
3.1.2 Concentrated hydrochloric acid (HCl)
3.2 Reagent preparation
3.2.1 Magnesium acetate solution (80 g/L). weigh 8.0 g of magnesium
acetate, add water to dissolve and set volume to 100 mL; well mix.
3.2.2 Magnesium acetate solution (240 g/L). weigh 24.0 g of magnesium
starch, wheat starch and rice starch, 10 g for corn starch and tapioca starch),
nearest to 0.0001 g. Evenly distribute the sample in the crucible. Do NOT
press.
5.3 Determination
5.3.1 Beans and their products, meat and poultry and their products, eggs
and their products, aquatic products and their products, milk and dairy
products of high phosphorus content
5.3.1.1 After weighing sample, add 1.00 mL of magnesium acetate solution
(240 g/L) or 3.00 mL of magnesium acetate solution (80 g/L) to make the
sample completely wet. After 10 min of placement, evaporate the water to
dryness on the water bath. Heat the sample on a hot plate with a small fire to
fully carbonize the sample to smoke-free. Then place it in the high
temperature furnace. Burn it at 550°C ± 25°C for 4 h. Cool it to around 200°C.
Take it out. Put it in the dryer for 30 min of cooling. Before weighing, if the
burning residues are found to have carbon particles, it shall drip a little water
into the sample to moist, loosing the agglomeration. Evaporate the water.
Burn it again till there are no carbon particles, which means the ashing is
completed. Then it can be weighed. Repeat burning till the difference
between two weighings before and after shall not exceed 0.5 mg. And that
shall be constant weight.
5.3.1.2 Pipet 3 magnesium acetate solutions of same concentration and
volume with 5.3.1.1. Carry out 3 reagent blank tests. When the standard
deviation of 3 test results is less than 0.003 g, take the arithmetic mean as the
blank value. If the standard deviation exceeds or equals to 0.003 g, it shall
carry out the blank value test one more time.
5.3.2 Starchy food
Place the crucible on a high temperature oven or a hot plate. Half-lid the
crucible cover. Carefully heat the sample to completely carbonize to
smoke-free in a ventilated condition. Immediately place the crucible in a high
temperature oven. Raise the temperature to 900°C ± 25°C. Keep this
temperature until the remaining carbon disappears. Generally, it takes 1 h to
complete the ashing. Cool it to around 200°C. Take it out. Put it into the dryer
to cool for 30 min. Before weighing, if the burning residues are found to have
carbon particles, it shall drip a little water into the sample to moist, loosing the
agglomeration. Evaporate the water. Burn it again till there are no carbon
particles, which means the ashing is completed. Then it can be weighed.
Repeat burning till the difference between two weighings before and after
shall not exceed 0.5 mg. And that shall be constant weight.
5.3.3 Other foods
m3 - masses of crucible and sample, in grams (g);
w - sample dry matter content (mass fraction), %;
100 - unit conversion factor.
When the ash content in sample is ≥ 10 g/100g, three valid digits shall be
remained. When the ash content in sample is < 10 g/100g, two valid digits
shall be remained.
7 Precision
The absolute difference between the two independent determinations
obtained under reproducible conditions shall not exceed 5% of the arithmetic
mean.
Method Two Determination of water-soluble ash and
water-insoluble ash in foods
8 Principle
Extract the total ash with hot water. Filter by ashless filter paper. Burn.
Determine the water-insoluble ash. Calculate the water-soluble ash by the
mass difference between total ash and water-insoluble ash.
9 Reagents and materials
Unless otherwise stated, the water used in this method is Grade 3 water
specified in GB/T 6682.
10 Instruments and equipment
10.1 High temperature furnace. maximum temperature ≥ 950°C
10.2 Analysis balance. resolutions are 0.1 mg, 1 mg, 0.1 g
10.3 Quartz crucible or porcelain crucible
10.4 Dryer (with desiccant)
10.5 Ashless filter paper
10.6 Funnel
15 Reagents and materials
Unless otherwise stated, the reagents used in this method are of analytical
grade and water is Grade 3 water specified in GB/T 6682.
15.1 Reagents
Concentrated hydrochloric acid (HCl)
15.2 Reagent preparation
Use distilled water to dilute 10% hydrochloric ...
......
| Standard ID | GB 5009.4-2016 (GB5009.4-2016) | | Description (Translated English) | National food safety standard -- Determination of ash in foods | | Sector / Industry | National Standard | | Classification of Chinese Standard | C53 | | Classification of International Standard | 67.040 | | Word Count Estimation | 10,161 | | Date of Issue | 2016-08-31 | | Date of Implementation | 2017-03-01 | | Older Standard (superseded by this standard) | SN/T 0925-2000; SN/T 0923-2000; SN/T 0921-2000; NY/T 82.8-1988; GB/T 9825-2008; GB/T 9824-2008; GB/T 9695.18-2008; GB/T 8308-2013; GB/T 8307-2013; GB/T 8306-2013; GB/T 5505-2008; GB/T 22510-2008; GB/T 22427.1-2008; GB/T 17375-2008; GB/T 12729.9-2008; GB/T | | Regulation (derived from) | Announcement of the State Administration of Public Health and Family Planning 2016 No.11 |
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