GB 5009.42-2025 National food safety standard - Determination of edible salt parameters
1 Scope
This standard specifies the method for the determination of edible salt parameters.
This standard is applicable to the determination of edible salt parameters.
2 Sodium chloride
2.1 Moisture
2.1.1 Scope
The loss-on-drying method is applicable to the determination of moisture in refined salt, low sodium salt, and crushed and washed salt, while the ignition loss method is applicable to the determination of moisture in solar salt.
2.1.2 Loss-on-drying method
2.1.2.1 Principle
The specimen is dried at 140±2°C until constant weight is achieved, and its mass is weighted before and after drying. The moisture in edible salt is the sum of the loss on drying and the residual crystalline water in calcium sulfate, magnesium sulfate, calcium chloride, and magnesium chloride after drying.
2.1.2.2 Instruments and apparatus
2.1.2.2.1 Electronic balance: With a sensitivity of 0.0001 g.
2.1.2.2.2 Thermostatic drying oven.
2.1.2.2.3 Flat weighing bottle: 60 mm × 30 mm, dried to constant weight in a thermostatic drying oven at 140±2°C before use.
2.1.2.2.4 Desiccator: Containing effective desiccant.
2.1.2.3 Analytical steps
Weigh 10 g (to the nearest 0.0001 g) of a homogeneous specimen crushed to a size smaller than 2 mm in diameter and put it into a pre-weighed flat weighing bottle. Place the bottle in the thermostatic drying oven with the lid tilted against the bottle edge. Heat to 140±2°C and continue drying for 2 h. Cover the bottle, remove it from the oven, transfer it to a desiccator, cool to room temperature, and weigh. Subsequently, dry for 1 h each time and weigh (to the nearest 0.0001 g) until the difference between two consecutive weighing operations does not exceed 5 mg, indicating the realization of constant weight.
2.1.2.4 Expression of analysis results
The moisture content in the specimen shall be calculated using Equation (1):
(1)
Where,
X1——the moisture content in the specimen, g/100 g;
m1——the total mass of the specimen and the weighing bottle before drying, g;
m2——the total mass of the specimen and the weighing bottle after drying, g;
m——the mass of the specimen weighed, g;
100——the unit conversion factor;
ω1——the calcium sulfate content in the specimen, g/100 g;
0.0662——the conversion factor for residual crystalline water in calcium sulfate in edible salt after drying at 140°C;
ω2——the magnesium sulfate content in the specimen, g/100 g;
0.1497——the conversion factor for residual crystalline water in magnesium sulfate in edible salt after drying at 140°C;
ω3——the calcium chloride content in the specimen, g/100 g;
0.3246——the conversion factor for residual crystalline water in calcium chloride in edible salt after drying at 140°C;
ω4——the magnesium chloride content in the specimen, g/100 g;
0.3784——the conversion factor for residual crystalline water in magnesium chloride in edible salt after drying at 140°C.
For moisture content ≥ 1.00 g/100 g, retain three significant figures; for moisture content < 1.00 g/100 g, retain two significant figures.
2.1.2.5 Precision
For moisture content < 1.00 g/100 g, the absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 0.10 g/100 g; for moisture content between 1.00 g/100 g and 4.00 g/100 g, the absolute difference shall not exceed 0.20 g/100 g.
2.1.3 Ignition loss method
2.1.3.1 Principle
The specimen is ignited at 600°C, and its mass is weighted before and after ignition. The moisture content in edible salt is obtained by subtracting the mass loss of magnesium chloride from the ignition loss.
2.1.3.2 Instruments and apparatus
2.1.3.2.1 Electronic balance: With a sensitivity of 0.0001 g.
2.1.3.2.2 High-temperature furnace.
2.1.3.2.3 Porcelain crucible: 60 mm × 60 mm (with an inner lid), ignited at 600°C in a high-temperature furnace for 1 h before use, then naturally cooled to below 200°C and removed. Place the porcelain crucible on a clean porcelain plate to cool for 5–6 min, transfer it into a desiccator, leave it cool to room temperature, and weigh.
2.1.3.2.4 Desiccator: Containing effective desiccant.
2.1.3.3 Analytical steps
Weigh 3 g (to the nearest 0.0001 g) of a homogeneous specimen crushed to a size smaller than 2 mm in diameter and put it into a pre-weighed porcelain crucible. Cover it with the inner and outer lids, and place the porcelain crucible in the high-temperature furnace, then heat to 600°C, and continue ignition for 1 h. After that, stop ignition, allow it to cool naturally to below 200°C, and remove. Place the porcelain crucible on a clean porcelain plate to cool for 5–6 min, transfer it into a desiccator, leave it cool to room temperature, and weigh (to the nearest 0.0001 g).
Contents
Foreword III
1 Scope
2 Sodium chloride
3 Potassium chloride
4 Iodine
5 Barium
6 Potassium ferrocyanide
7 Lead
8 Total arsenic
9 Cadmium
10 Total mercury
11 Determination of multiple elements in edible Salt
Standard
GB 5009.42-2025 National food safety standard - Determination of salt index (English Version)
Standard No.
GB 5009.42-2025
Status
valid
Language
English
File Format
PDF
Word Count
21000 words
Price(USD)
630.0
Implemented on
2025-9-16
Delivery
via email in 1~5 business day
Detail of GB 5009.42-2025
Standard No.
GB 5009.42-2025
English Name
National food safety standard - Determination of salt index
Chinese Name
食品安全国家标准 食用盐指标的测定
Chinese Classification
Professional Classification
GB
ICS Classification
Issued by
National Health Commission of the People's Republic of China, State Administration for Market Regulation
GB 5009.42-2025 National food safety standard - Determination of edible salt parameters
1 Scope
This standard specifies the method for the determination of edible salt parameters.
This standard is applicable to the determination of edible salt parameters.
2 Sodium chloride
2.1 Moisture
2.1.1 Scope
The loss-on-drying method is applicable to the determination of moisture in refined salt, low sodium salt, and crushed and washed salt, while the ignition loss method is applicable to the determination of moisture in solar salt.
2.1.2 Loss-on-drying method
2.1.2.1 Principle
The specimen is dried at 140±2°C until constant weight is achieved, and its mass is weighted before and after drying. The moisture in edible salt is the sum of the loss on drying and the residual crystalline water in calcium sulfate, magnesium sulfate, calcium chloride, and magnesium chloride after drying.
2.1.2.2 Instruments and apparatus
2.1.2.2.1 Electronic balance: With a sensitivity of 0.0001 g.
2.1.2.2.2 Thermostatic drying oven.
2.1.2.2.3 Flat weighing bottle: 60 mm × 30 mm, dried to constant weight in a thermostatic drying oven at 140±2°C before use.
2.1.2.2.4 Desiccator: Containing effective desiccant.
2.1.2.3 Analytical steps
Weigh 10 g (to the nearest 0.0001 g) of a homogeneous specimen crushed to a size smaller than 2 mm in diameter and put it into a pre-weighed flat weighing bottle. Place the bottle in the thermostatic drying oven with the lid tilted against the bottle edge. Heat to 140±2°C and continue drying for 2 h. Cover the bottle, remove it from the oven, transfer it to a desiccator, cool to room temperature, and weigh. Subsequently, dry for 1 h each time and weigh (to the nearest 0.0001 g) until the difference between two consecutive weighing operations does not exceed 5 mg, indicating the realization of constant weight.
2.1.2.4 Expression of analysis results
The moisture content in the specimen shall be calculated using Equation (1):
(1)
Where,
X1——the moisture content in the specimen, g/100 g;
m1——the total mass of the specimen and the weighing bottle before drying, g;
m2——the total mass of the specimen and the weighing bottle after drying, g;
m——the mass of the specimen weighed, g;
100——the unit conversion factor;
ω1——the calcium sulfate content in the specimen, g/100 g;
0.0662——the conversion factor for residual crystalline water in calcium sulfate in edible salt after drying at 140°C;
ω2——the magnesium sulfate content in the specimen, g/100 g;
0.1497——the conversion factor for residual crystalline water in magnesium sulfate in edible salt after drying at 140°C;
ω3——the calcium chloride content in the specimen, g/100 g;
0.3246——the conversion factor for residual crystalline water in calcium chloride in edible salt after drying at 140°C;
ω4——the magnesium chloride content in the specimen, g/100 g;
0.3784——the conversion factor for residual crystalline water in magnesium chloride in edible salt after drying at 140°C.
For moisture content ≥ 1.00 g/100 g, retain three significant figures; for moisture content < 1.00 g/100 g, retain two significant figures.
2.1.2.5 Precision
For moisture content < 1.00 g/100 g, the absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 0.10 g/100 g; for moisture content between 1.00 g/100 g and 4.00 g/100 g, the absolute difference shall not exceed 0.20 g/100 g.
2.1.3 Ignition loss method
2.1.3.1 Principle
The specimen is ignited at 600°C, and its mass is weighted before and after ignition. The moisture content in edible salt is obtained by subtracting the mass loss of magnesium chloride from the ignition loss.
2.1.3.2 Instruments and apparatus
2.1.3.2.1 Electronic balance: With a sensitivity of 0.0001 g.
2.1.3.2.2 High-temperature furnace.
2.1.3.2.3 Porcelain crucible: 60 mm × 60 mm (with an inner lid), ignited at 600°C in a high-temperature furnace for 1 h before use, then naturally cooled to below 200°C and removed. Place the porcelain crucible on a clean porcelain plate to cool for 5–6 min, transfer it into a desiccator, leave it cool to room temperature, and weigh.
2.1.3.2.4 Desiccator: Containing effective desiccant.
2.1.3.3 Analytical steps
Weigh 3 g (to the nearest 0.0001 g) of a homogeneous specimen crushed to a size smaller than 2 mm in diameter and put it into a pre-weighed porcelain crucible. Cover it with the inner and outer lids, and place the porcelain crucible in the high-temperature furnace, then heat to 600°C, and continue ignition for 1 h. After that, stop ignition, allow it to cool naturally to below 200°C, and remove. Place the porcelain crucible on a clean porcelain plate to cool for 5–6 min, transfer it into a desiccator, leave it cool to room temperature, and weigh (to the nearest 0.0001 g).
Contents of GB 5009.42-2025
Contents
Foreword III
1 Scope
2 Sodium chloride
3 Potassium chloride
4 Iodine
5 Barium
6 Potassium ferrocyanide
7 Lead
8 Total arsenic
9 Cadmium
10 Total mercury
11 Determination of multiple elements in edible Salt
