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Determination of sodium formaldehyde sulfoxylate in wheat flour, rice flour and their products
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| GB/T 21126-2007 | English | 159 |
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Determination of sodium formaldehyde sulfoxylate in grain products
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Standard similar to GB/T 21126-2026 GB/T 21315 | GB/T 21311 | GB/T 20744 | GB/T 12766 | GB/T 21119 | Basic data | Standard ID | GB/T 21126-2026 (GB/T21126-2026) | | Description (Translated English) | Determination of sodium formaldehyde sulfoxylate in wheat flour, rice flour and their products | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | X04 | | Classification of International Standard | 67.050 | | Date of Issue | 2026-03-31 | | Date of Implementation | 2026-10-01 | | Older Standard (superseded by this standard) | GB/T 21126-2007 | | Issuing agency(ies) | State Administration for Market Regulation, Standardization Administration of China | GB/T 21126-2007: Determination of sodium formaldehyde sulfoxylate in grain products---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Determination of sodium formaldehyde sulfoxylate in grain products
ICS 67.050
X04
National Standards of People's Republic of China
Wheat flour and rice flour and their products
Determination of formaldehyde sodium bisulfate content
2007-10-16 released
2008-05-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China
China National Standardization Administration released
Foreword
This standard proposed by the State Food Administration.
This standard by the National Grain and Oil Standardization Technical Committee.
This standard was drafted. Henan University of Technology, National Cereals and Oils Quality Supervision and Inspection Center, Shaanxi Province, grain and oil product quality supervision and inspection.
The main drafters of this standard. Huo Gong Gong, Fan Lu, Zhou Zhanming, Shang Yan E, the party Xianmin, Liu Xu, He Lijun, Zhang Hao.
Wheat flour and rice flour and their products
Determination of formaldehyde sodium bisulfate content
1 Scope
This standard specifies the use of high performance liquid chromatography determination of wheat flour and rice flour and formaldehyde and formaldehyde in the principle of sodium sulfoxylate,
Reagents, instruments, sample preparation, high performance liquid chromatography, calculation of results and precision.
This standard applies to the determination of residual formaldehyde and formaldehyde sodium sulfoxylate in wheat flour, rice flour and their products.
The detection limit of this standard is 0.08μg/g.
2 Normative references
The following documents contain provisions which, through reference in this standard and become the standard terms. All dated references, which are subsequently owned
Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to reach an agreement based on this standard research
Whether you can use the latest versions of these files. For undated references, the latest version applies to this standard.
GB/T 2912.1-1998 Textiles - Determination of formaldehyde - Part 1. Free-hydrolyzed formaldehyde (water extraction method)
3 principle
In acidic solution, the sample formaldehyde formaldehyde sodium bisulfite residual formaldehyde released by the water extraction, extraction of formaldehyde and 2,4-
Dinitrophenylhydrazine addition reaction occurred, resulting in yellow 2,4-dinitrophenylhydrazone, with n-hexane extraction, the high performance liquid chromatography separation, and
The retention times of standard formaldehyde derivatives were qualitatively controlled and quantified using standard curve methods.
4 reagent
The chemicals used, n-hexane for the chromatographic purity, the rest were of analytical grade. Water used in the solution are treated with potassium permanganate after the weight
Steam.
4.1 hydrochloric acid - sodium chloride solution. Weigh 20g of sodium chloride in 1000mL volumetric flask, dissolved in a small amount of water, add 60mL37% hydrochloric acid, add
Water to scale.
4.2 Formaldehyde standard stock solution. Take 1mL36% ~ 38% formaldehyde solution, water volume to 500mL, press GB/T 2912.1-1998 before use
Sodium sulfite method for the determination of formaldehyde concentration. Or formulated with standard solution of formaldehyde 40μg/mL standard stock solution, the solution was placed 4 ℃ ice
The box can be stored for 1 month.
4.3 Formaldehyde standard solution. accurately measure a certain amount of standard formaldehyde standard stock solution, configured to 2μg/mL of formaldehyde standard use
Liquid, this standard solution must be used on the day of preparation.
4.4 Disodium hydrogen phosphate solution. Weigh 18gNa2HPO4 · 12H2O, dissolved in water and dilute to 100mL.
4.5 2,4-Dinitrophenylhydrazine (DNPH) Purification. Weigh about 20g of 2,4-dinitrophenylhydrazine (DNPH) in a beaker, add 167mL of acetonitrile and
500mL water, stirred until completely dissolved, placed overnight. Filter with a qualitative filter paper crystallization, respectively, with water and ethanol repeatedly washed five times to six times
Placed in a desiccator spare.
4.6 Derivatives. weighed purified 2,4-dinitrophenylhydrazine (DNPH).200mg, dissolved in acetonitrile and volume to 100mL.
4.7 Mobile phase. acetonitrile + water mixed solution [V (acetonitrile) + V (water) = 70 + 30], filtered with a 0.45 μm pore size filter and set aside.
4.8 n-hexane.
5 instruments
5.1 stopper flask. 150mL, 250mL.
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