GB 5009.137-2025 National food safety standard - Determination of antimony in foods
1 Scope
This standard specifies the methods for the determination of antimony in foods by hydride generation - atomic fluorescence spectrometry and inductively coupled plasma mass spectrometry.
This standard is applicable to the determination of antimony in foods.
Method I Hydride generation - atomic fluorescence spectrometry
2 Principle
After the specimen is heated and dissolved by acid, the antimony in the specimen reacts with sodium borohydride or potassium borohydride in the acidic medium and forms volatile antimony hydride, which is carried into the atomizer by a carrier gas for atomization. Atomic fluorescence is generated under excitation by an antimony hollow cathode lamp. The fluorescence intensity, which is in direct proportion to the antimony content, is quantitatively measured by external standard method.
3 Reagents and materials
Unless otherwise specified, guaranteed reagents and Class-II water (defined in GB/T 6682) are adopted for the purpose of this method.
3.1 Reagents
3.1.1 Nitric acid (HNO3).
3.1.2 Hydrochloric acid (HCl).
3.1.3 Perchloric acid (HClO4).
3.1.4 Thiourea [(NH2)2CS]: Analytical grade.
3.1.5 Potassium iodide (KI): Analytical grade.
3.1.6 Ascorbic acid (C6H8O6): Analytical grade.
3.1.7 Potassium borohydride (KBH4) or sodium borohydride (NaBH4).
3.1.8 Potassium hydroxide (KOH) or sodium hydroxide (NaOH).
3.1.9 Tartaric acid (C4H6O6): Purity ≥ 99.5%.
3.1.10 Argon (Ar): Purity > 99.99%.
3.2 Preparation of reagents
3.2.1 Nitric acid-perchloric acid mixture (10+1): Measure 10 mL of perchloric acid and slowly add it to 100 mL of nitric acid and mix well.
3.2.2 Hydrochloric acid solution (1+1): Measure 50 mL of hydrochloric acid and add it into 50 mL of water, then mix well.
3.2.3 Thiourea-ascorbic acid solution: Weigh 10.0 g of thiourea and 10.0 g of ascorbic acid, respectively, dissolve them in 100 mL of water, mix well, and store the solution away from light. Prepare it immediately before use.
3.2.4 Thiourea-potassium iodide solution: Weigh 2.0 g of thiourea and 10.0 g of potassium iodide, respectively, dissolve them in 100 mL of water, mix well, and store the solution away from light. Prepare it immediately before use.
3.2.5 Potassium hydroxide solution (5.0 g/L): Weigh 5.0 g of potassium hydroxide, dissolve it in water and dilute to 1,000 mL, then mix well. Prepare it immediately before use. Sodium hydroxide may also be used instead of potassium hydroxide in this solution.
3.2.6 Potassium borohydride solution (20 g/L): Weigh 10.0 g of potassium borohydride, dissolve it in potassium hydroxide solution (5.0 g/L), and dilute to 500 mL, then mix well. Prepare it immediately before use. Potassium borohydride in this solution may also be replaced with 7.0 g of sodium borohydride.
3.2.7 Nitric acid solution (1+5): Measure 100 mL of nitric acid, add it to 500 mL of water, and mix well.
3.2.8 Hydrochloric acid solution (5+95): Measure 50 mL of hydrochloric acid, add it to 950 mL of water, and mix well.
3.2.9 Nitric acid solution (1+1): Measure 50 mL of nitric acid, add it to 50 mL of water, and mix well.
3.2.10 Nitric acid solution (2.5 mol/L): Measure 173 mL of nitric acid, dissolve it in water and dilute to 1,000 mL, then mix well.
3.3 Standards
Metallic antimony (Sb, CAS No.: 7440-36-0): Purity > 99.99%.
3.4 Preparation of standard solutions
3.4.1 Antimony standard stock solution (1,000 mg/L): Weigh 0.50 g (accurate to 0.0001 g) of metallic antimony, and place it into a beaker; add 5.0 g of tartaric acid and 10.0 mL of nitric acid solution (1+1) into the beaker to dissolve it; then transfer the solution into a 500-mL volumetric flask and dilute it to the scale with 2.5 mol/L nitric acid solution, and mix well; place the solution in a polyethylene plastic bottle, store it at room temperature and protect it from light, with a shelf life of 2 years. Antimony standard solution certified by the state and granted a standard substance certificate may also be used as an alternative.
3.4.2 Antimony standard intermediate solution (100 mg/L): Accurately pipette 1.00 mL of the antimony standard stock solution (1,000 mg/L), and place it into a 10-mL volumetric flask, then dilute it to scale with water, and mix well; place the solution into a polyethylene plastic bottle and seal it, then store it away from light at 0–5℃, with a shelf life of 6 months.
3.4.3 Antimony standard working solution (1.00 mg/L): Accurately pipette 1.00 mL of the antimony standard intermediate solution (100 mg/L) and place it into a 100-mL volumetric flask, then dilute it to scale with water, and mix well; place the solution into a polyethylene plastic bottle and seal it, then store it away from light at 0–5℃, with a shelf life of 1 month.
3.4.4 Antimony standard solution series: Accurately pipette 0 mL, 0.100 mL, 0.200 mL, 0.400 mL, 0.600 mL, 0.800 mL, 1.00 mL, and 2.00 mL of the antimony standard working solution (1.00 mg/L), respectively, and place them into 100-mL volumetric flasks; add a small amount of water to dilute them, then add 10 mL of hydrochloric acid solution (1+1) and 10 mL of either the thiourea-potassium iodide solution or the thiourea-ascorbic acid solution; dilute them to scale with water and mix well. The mass concentrations of this series of antimony standard solutions are 0 μg/L, 1.00 μg/L, 2.00 μg/L, 4.00 μg/L, 6.00 μg/L, 8.00 μg/L, 10.0 μg/L, and 20.0 μg/L, respectively. Allow them to stand for 1 h before determination. Prepare it immediately before use.
Note: The mass concentration range of antimony in the standard solution series may be determined according to the instrument sensitivity, the actual antimony content in the samples, and different instrument models.
4 Apparatus
Note: All glassware and polytetrafluoroethylene digestion inner tanks and inner caps shall be soaked in nitric acid solution (1+5) overnight, flushed with tap water repeatedly, and finally washed clean with water.
4.1 Atomic fluorescence spectrometer: Equipped with an antimony hollow cathode lamp.
4.2 Balance: With a sensitivity of 1 mg and 0.1 mg, respectively.
4.3 Adjustable electric heating plate.
4.4 Adjustable electric furnace.
Contents
Foreword I
1 Scope
2 Principle
3 Reagents and materials
4 Apparatus
5 Analytical procedures
6 Expression of analysis results
7 Precision
8 Others
Annex A Reference conditions for microwave digestion instrument
Standard
GB 5009.137-2025 National food safety standard - Determination of antimony in foods (English Version)
Standard No.
GB 5009.137-2025
Status
valid
Language
English
File Format
PDF
Word Count
3500 words
Price(USD)
105.0
Implemented on
2025-9-16
Delivery
via email in 1~3 business day
Detail of GB 5009.137-2025
Standard No.
GB 5009.137-2025
English Name
National food safety standard - Determination of antimony in foods
Chinese Name
食品安全国家标准 食品中锑的测定
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 5009.137-2025 National food safety standard - Determination of antimony in foods
1 Scope
This standard specifies the methods for the determination of antimony in foods by hydride generation - atomic fluorescence spectrometry and inductively coupled plasma mass spectrometry.
This standard is applicable to the determination of antimony in foods.
Method I Hydride generation - atomic fluorescence spectrometry
2 Principle
After the specimen is heated and dissolved by acid, the antimony in the specimen reacts with sodium borohydride or potassium borohydride in the acidic medium and forms volatile antimony hydride, which is carried into the atomizer by a carrier gas for atomization. Atomic fluorescence is generated under excitation by an antimony hollow cathode lamp. The fluorescence intensity, which is in direct proportion to the antimony content, is quantitatively measured by external standard method.
3 Reagents and materials
Unless otherwise specified, guaranteed reagents and Class-II water (defined in GB/T 6682) are adopted for the purpose of this method.
3.1 Reagents
3.1.1 Nitric acid (HNO3).
3.1.2 Hydrochloric acid (HCl).
3.1.3 Perchloric acid (HClO4).
3.1.4 Thiourea [(NH2)2CS]: Analytical grade.
3.1.5 Potassium iodide (KI): Analytical grade.
3.1.6 Ascorbic acid (C6H8O6): Analytical grade.
3.1.7 Potassium borohydride (KBH4) or sodium borohydride (NaBH4).
3.1.8 Potassium hydroxide (KOH) or sodium hydroxide (NaOH).
3.1.9 Tartaric acid (C4H6O6): Purity ≥ 99.5%.
3.1.10 Argon (Ar): Purity > 99.99%.
3.2 Preparation of reagents
3.2.1 Nitric acid-perchloric acid mixture (10+1): Measure 10 mL of perchloric acid and slowly add it to 100 mL of nitric acid and mix well.
3.2.2 Hydrochloric acid solution (1+1): Measure 50 mL of hydrochloric acid and add it into 50 mL of water, then mix well.
3.2.3 Thiourea-ascorbic acid solution: Weigh 10.0 g of thiourea and 10.0 g of ascorbic acid, respectively, dissolve them in 100 mL of water, mix well, and store the solution away from light. Prepare it immediately before use.
3.2.4 Thiourea-potassium iodide solution: Weigh 2.0 g of thiourea and 10.0 g of potassium iodide, respectively, dissolve them in 100 mL of water, mix well, and store the solution away from light. Prepare it immediately before use.
3.2.5 Potassium hydroxide solution (5.0 g/L): Weigh 5.0 g of potassium hydroxide, dissolve it in water and dilute to 1,000 mL, then mix well. Prepare it immediately before use. Sodium hydroxide may also be used instead of potassium hydroxide in this solution.
3.2.6 Potassium borohydride solution (20 g/L): Weigh 10.0 g of potassium borohydride, dissolve it in potassium hydroxide solution (5.0 g/L), and dilute to 500 mL, then mix well. Prepare it immediately before use. Potassium borohydride in this solution may also be replaced with 7.0 g of sodium borohydride.
3.2.7 Nitric acid solution (1+5): Measure 100 mL of nitric acid, add it to 500 mL of water, and mix well.
3.2.8 Hydrochloric acid solution (5+95): Measure 50 mL of hydrochloric acid, add it to 950 mL of water, and mix well.
3.2.9 Nitric acid solution (1+1): Measure 50 mL of nitric acid, add it to 50 mL of water, and mix well.
3.2.10 Nitric acid solution (2.5 mol/L): Measure 173 mL of nitric acid, dissolve it in water and dilute to 1,000 mL, then mix well.
3.3 Standards
Metallic antimony (Sb, CAS No.: 7440-36-0): Purity > 99.99%.
3.4 Preparation of standard solutions
3.4.1 Antimony standard stock solution (1,000 mg/L): Weigh 0.50 g (accurate to 0.0001 g) of metallic antimony, and place it into a beaker; add 5.0 g of tartaric acid and 10.0 mL of nitric acid solution (1+1) into the beaker to dissolve it; then transfer the solution into a 500-mL volumetric flask and dilute it to the scale with 2.5 mol/L nitric acid solution, and mix well; place the solution in a polyethylene plastic bottle, store it at room temperature and protect it from light, with a shelf life of 2 years. Antimony standard solution certified by the state and granted a standard substance certificate may also be used as an alternative.
3.4.2 Antimony standard intermediate solution (100 mg/L): Accurately pipette 1.00 mL of the antimony standard stock solution (1,000 mg/L), and place it into a 10-mL volumetric flask, then dilute it to scale with water, and mix well; place the solution into a polyethylene plastic bottle and seal it, then store it away from light at 0–5℃, with a shelf life of 6 months.
3.4.3 Antimony standard working solution (1.00 mg/L): Accurately pipette 1.00 mL of the antimony standard intermediate solution (100 mg/L) and place it into a 100-mL volumetric flask, then dilute it to scale with water, and mix well; place the solution into a polyethylene plastic bottle and seal it, then store it away from light at 0–5℃, with a shelf life of 1 month.
3.4.4 Antimony standard solution series: Accurately pipette 0 mL, 0.100 mL, 0.200 mL, 0.400 mL, 0.600 mL, 0.800 mL, 1.00 mL, and 2.00 mL of the antimony standard working solution (1.00 mg/L), respectively, and place them into 100-mL volumetric flasks; add a small amount of water to dilute them, then add 10 mL of hydrochloric acid solution (1+1) and 10 mL of either the thiourea-potassium iodide solution or the thiourea-ascorbic acid solution; dilute them to scale with water and mix well. The mass concentrations of this series of antimony standard solutions are 0 μg/L, 1.00 μg/L, 2.00 μg/L, 4.00 μg/L, 6.00 μg/L, 8.00 μg/L, 10.0 μg/L, and 20.0 μg/L, respectively. Allow them to stand for 1 h before determination. Prepare it immediately before use.
Note: The mass concentration range of antimony in the standard solution series may be determined according to the instrument sensitivity, the actual antimony content in the samples, and different instrument models.
4 Apparatus
Note: All glassware and polytetrafluoroethylene digestion inner tanks and inner caps shall be soaked in nitric acid solution (1+5) overnight, flushed with tap water repeatedly, and finally washed clean with water.
4.1 Atomic fluorescence spectrometer: Equipped with an antimony hollow cathode lamp.
4.2 Balance: With a sensitivity of 1 mg and 0.1 mg, respectively.
4.3 Adjustable electric heating plate.
4.4 Adjustable electric furnace.
Contents of GB 5009.137-2025
Contents
Foreword I
1 Scope
2 Principle
3 Reagents and materials
4 Apparatus
5 Analytical procedures
6 Expression of analysis results
7 Precision
8 Others
Annex A Reference conditions for microwave digestion instrument
