GB/T 19941.1-2025 PDF English
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GB/T 19941.1: Historical versions
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| GB/T 19941.1-2025 | 215 | Add to Cart | Auto, 9 seconds. | Leather and fur - Determination of formaldehyde content - Part 1: High-performance liquid chromatography method | Valid |
| GB/T 19941.1-2019 | 175 | Add to Cart | Auto, 9 seconds. | Leather and fur -- Determination of formaldehyde content -- Part 1: High performance liquid chromatography method | Valid |
| GB/T 19941-2005 | 125 | Add to Cart | Auto, 9 seconds. | Leather and fur -- Chemical tests -- Determination of formaldehyde content | Obsolete |
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GB/T 19941.1-2025: Leather and fur - Determination of formaldehyde content - Part 1: High-performance liquid chromatography method
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GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 59.140.30 CCS Y 46 Replacing GB/T 19941.1-2019 Leather and fur -- Determination of formaldehyde content -- Part 1.High-performance liquid chromatography method (ISO 17226-1.2021, Leather -- Determination of formaldehyde content -- Part 1. Method using high-performance liquid chromatography, MOD) Issued on: DECEMBER 02, 2025 Implemented on: JANUARY 01, 2027 Issued by. State Administration for Market Regulation; Standardization Administration of the People's Republic of China.
Table of Contents
Foreword... 3 Introduction... 6 1 Scope... 7 2 Normative references... 7 3 Terms and definitions... 7 4 Principle... 8 5 Reagents and materials... 8 6 Instruments and equipment... 8 7 Sampling and specimen preparation... 9 8 Test steps... 9 9 Representation of the calculated results... 12 10 Feasibility of the method... 14 11 Test report... 14 Annex A (informative) Comparison on structural numbering changes between this document and ISO 17226-1.2021... 15 Annex B (informative) Technical differences between this document and ISO 17226- 1.2021 and the reasons thereof... 16 Annex C (informative) HPLC analysis conditions... 18 Annex D (informative) Precision. Reliability of HPLC method... 19Foreword
This document was drafted in accordance with the rules given in GB/T 1.1-2020 "Directives for standardization - Part 1.Rules for the structure and drafting of standardizing documents". This document is Part 1 of GB/T 19941 "Leather and fur -- Determination of formaldehyde content". The following parts of GB/T 19941 have been issued. - Part 1.High performance liquid chromatography method; - Part 2.Colorimetric method; - Part 3.Formaldehyde emissions. This document replaces GB/T 19941.1-2019 "Leather and fur -- Determination of formaldehyde content - Part 1.High performance liquid chromatography method". Compared with GB/T 19941.1-2019, apart from structural adjustments and editorial changes, the main technical changes are as follows. - The preparation method for DNPH solution has been changed (see 5.10 of this Edition; 4.3 of Edition 2019); - The following has been added. "A water bath or oven, with temperature controllable at (50 ± 2)°C" (see 6.5 of this Edition); - The guidelines now include provisions for removing residual glue from samples (see 7.1 of this Edition); - The test for fur specimens with fur has been added (see Chapter 7 of this Edition); - The deviation requirements for extraction temperature have been changed (see 8.2.1 of this Edition; 6.2 of Edition 2019); - The conditions (such as temperature and time) for the reaction of formaldehyde with DNPH have been changed (see 8.2.2 of this Edition; 6.3 of Edition 2019); - The method for creating the standard working curve has been changed (see 8.2.4 of this Edition; 6.5 of Edition 2019); - The preparation method of formaldehyde standard solution when using formaldehyde stock solution to create a standard working curve has been modified (see 8.2.4.1 of this Edition; 6.5.1 of Edition 2019); - The requirement regarding the solution standing time when preparing a standard working curve using DNPH-formaldehyde solution has been deleted (see 6.5.2 of Edition 2019); Leather and fur -- Determination of formaldehyde content -- Part 1.High-performance liquid chromatography method1 Scope
This document specifies a test method for determining the content of free and hydrolyzed formaldehyde in leather and fur using high performance liquid chromatography. This document applies to the determination of formaldehyde content in various types of leather, fur, and their products. NOTE. The method specified in this document is selective and less affected by colored extracts, making it particularly suitable for the precise quantification of formaldehyde content.2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 6682, Water for analytical laboratory use -- Specification and test methods (GB/T 6682-2008, ISO 3696.1987, MOD) GB/T 39364, Leather - Chemical, physical, mechanical and fastness tests -- Sampling location (GB/T 3936-2020, ISO 2418.2017, MOD) QB/T 1267, Fur. Chemical, physical and mechanical and fastness tests. Sampling location QB/T 1272, Fur. Preparation of chemical test samples QB/T 1273, Fur. Chemical tests. Determination of volatile matter QB/T 2716, Leather -- Preparation of chemical test samples QB/T 2717, Leather -- Chemical tests -- Determination of volatile3 Terms and definitions
This document does not contain any terms or definitions that need to be defined.4 Principle
Leather or fur specimens are extracted under specified conditions. The extract is mixed with 2,4-dinitrophenyl ether. Different types of aldehydes and ketones react with the extract to form their respective hydrazones. After separation, the samples are determined by high-performance liquid chromatography (HPLC) with a UV detector or a diode array detector (DAD). NOTE. This document measures the total amount of free and hydrolyzed formaldehyde extracted from leather and fur under standard conditions.5 Reagents and materials
5.1 Unless otherwise specified, all reagents used are analytically pure. The water used in the tests shall meet the requirements for Grade III water in GB/T 6682, and all solutions used shall be aqueous solutions. 5.2 Formaldehyde solution. the mass fraction is approximately 37%. NOTE. Formaldehyde and formaldehyde-2,4-dinitrophenyl ether solutions are commercially available. If using commercially available solutions, procedure 8.1 is unnecessary. 5.3 Iodine solution. 0.05 mol/L, which means it contains 12.68 g of iodine per liter. 5.4 Sodium hydroxide (NaOH) solution. 2.0 mol/L. 5.5 Sulfuric acid (H2SO4) solution. 2.0 mol/L. 5.6 Sodium thiosulfate (Na2S2O3) solution. 0.1 mol/L. 5.7 Starch solution. 1% by mass, that is, 1 g of starch are dissolved in 100 mL of water. 5.8 Acetonitrile. chromatographically pure. 5.9 Extraction solution. 0.1% by mass, i.e., 1 g of sodium dodecyl sulfonate or sodium dodecyl sulfate are dissolved in 1000 mL of water. 5.10 2,4-Dinitrophenylhydrazine (DNPH) solution. dissolve 0.3 g of DNPH (2,4- dinitrophenylhydrazine) in 100 mL of acetonitrile (5.8).6 Instruments and equipment
6.1 Volumetric flasks. 10 mL, 500 mL and 1000 mL. 6.2 Erlenmeyer flasks. with stoppers or screw caps, 100 mL and 250 mL. 6.3 Glass fiber filter. GF8 (or glass filter G3, diameter is 70 mm~100 mm). 6.4 Water bath. temperature controllable up to (40 ± 2)°C, equipped with an oscillation device with an oscillation frequency of (50 ± 10) r/min. 6.5 Water bath or oven. temperature controllable up to (50 ± 2)°C. 6.6 High performance liquid chromatograph. equipped with a UV detector or diode array detector. 6.7 Membrane filters. such as polyamide membranes, with a pore size of 0.45µm. 6.8 Analytical balance. scale division value is 0.1 mg.7 Sampling and specimen preparation
7.1 Sampling The leather is manufactured in accordance with GB/T 39364. The sampling of fur shall be conducted in accordance with the provisions of QB/T 1267. During the sampling process, care shall be taken to avoid damage to the fur and to keep the fur intact. If sampling cannot be taken from a standard location (such as directly from shoes or clothing), specimens shall be taken from any location within the available area. The samples shall be representative, and this shall be noted in the test report. Residual glue on the sample shall be removed by physical methods. 7.2 Specimen preparation The leather shall be manufactured in accordance with the provisions of QB/T 2716. The fur shall be tested in accordance with the provisions of QB/T 1272.The test specimen shall be tested together with the fur. If the test results are based on the oven-dry weight of the specimen, the volatile content of another leather or fur specimen shall be determined in accordance with the provisions of QB/T 2717 or QB/T 1273.8 Test steps
8.1 Determination of formaldehyde content in stock solution 8.1.1 Preparation of formaldehyde stock solution ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al.
