GB/T 41525-2022 PDF English
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Determination of migratable chromium(Ⅵ) in toy materials - Ion chromatography
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GB/T 41525-2022: PDF in English (GBT 41525-2022) GB/T 41525-2022
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 97.200.50
CCS Y 57
Determination of Migratable Chromium (VI)
in Toy Materials - Ion Chromatography
ISSUED ON: JULY 11, 2022
IMPLEMENTED ON: JULY 11, 2022
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative References ... 4
3 Terms and Definitions ... 4
4 Principle ... 5
5 Reagents ... 5
6 Apparatus ... 6
7 Classification of Toy Materials ... 6
8 Sampling and Preparation of Sample ... 7
9 Migration Test ... 7
10 Adjustment of pH Value of Migration Solution ... 7
11 Analysis ... 8
12 Blank Test... 9
13 Calculation of Results ... 9
14 Mass Control ... 10
15 Test Report ... 10
Appendix A (Informative) Test Condition ... 11
Appendix B (Informative) Precision ... 14
Determination of Migratable Chromium (VI)
in Toy Materials - Ion Chromatography
WARNING: Persons using this Document shall have practical experience working in
formal laboratory. This document does not address all possible security issues. It is the
user's responsibility to take appropriate safety and health measures and to ensure
compliance with the conditions stipulated by relevant national regulations.
1 Scope
This Document describes the use of ion chromatography to determine the migratable chromium
(VI) in toy materials.
This Document is applicable to the achievable toy materials:
--- Category-1: dry, brittle, powdery or pliable toy materials;
--- Category-2: liquid or sticky toy materials;
--- Category-3: scratchable toy materials.
2 Normative References
The provisions in following documents become the essential provisions of this Document
through reference in this Document. For the dated documents, only the versions with the dates
indicated are applicable to this Document; for the undated documents, only the latest version
(including all the amendments) is applicable to this Document.
GB/T 6682 Water for Analytical Laboratory Use - Specification and Test Methods
EN 71-3 Safety of Toys – Part 3: Migration of Certain Elements
3 Terms and Definitions
For the purposes of this Document, the terms and definitions given in EN 71-3 apply.
4 Principle
Migratable chromium (Ⅵ) is a Cr (Ⅵ) leachate extracted from the toy material under the
condition that the toy material is continuously in contact with gastric acid for a period of time
after being swallowed. In this Document, Cr (VI) was separated by anion exchange column and
reacted with post-column derivatizing agent under certain pH conditions to form a purple-red
complex, which can be determined by ultraviolet-visible (UV-Vis) detector; and quantify by the
external standard method.
5 Reagents
Unless otherwise stated, only reagents confirmed to be analytically pure are used in the analysis.
5.1 Water, at least meet the requirements of Class-3 water specified in GB/T 6682.
5.2 0.07mol/L hydrochloric acid solution, c(HCl) = (0.07±0.005) mol/L.
5.3 Ammonia water, the mass fraction is 25%~28%.
5.4 Ammonia water (1+4), take 20mL of ammonia (5.3) and dilute to 100mL with water (5.1).
5.5 For 0.7mol/L ammonia solution, take 5.3mL of ammonia water (5.3) and dilute it with water
(5.1) to 100mL.
5.6 For 0.035mol/L ammonium chloride solution, take 500mL of hydrochloric acid solution
(5.2); titrate ammonia water (5.4); adjust the pH value to 7~8; and make constant volume to
1000mL by water (5.1).
5.7 1,5-Diphenylcarbazide, C13H14N4O (CAS number: 140-22-7).
5.8 Methanol, CH3OH (CAS number: 67-56-1).
5.9 Sulfuric acid (ρ=1.84g/mL), the mass fraction is 98%.
5.10 Post-column derivatization agent: Accurately weigh 0.5g of 1,5-diphenylcarbazide (5.7)
and dissolve it in 100mL of methanol (5.8); add 25mL of sulfuric acid (5.9) to about 500mL of
water (5.1). After the sulfuric acid solution is cooled, transfer the above two solutions to a
1000mL volumetric flask; make constant volume to the mark with water (5.1); and filter with
a membrane filter.
5.11 Potassium dichromate (K2Cr2O7) standard substance, dried in an oven at (102±2) ℃ for
(16±2) h before use.
5.12 Cr (Ⅵ) standard stock solution (1mg/mL): Take 2.829g potassium dichromate (5.11);
dissolve, transfer, wash and make constant volume to a 1000mL volumetric flask with water
(5.1); each 1mL of solution contains 1mg of Cr (VI).
5.13 Cr (VI) standard solution (10μg/mL): Accurately pipette 1mL of Cr (VI) standard stock
solution (5.12) into a 100mL volumetric flask; dilute and make constant volume with water (5.1)
to the mark; each 1mL of solution contains 10μg of Cr (VI).
5.14 Cr (VI) standard solution (0.1μg/mL): Accurately pipette 1mL of Cr (VI) standard solution
(5.13) into a 100mL volumetric flask; dilute and make constant volume with water (5.1) to the
mark; each 1mL of solution contains 0.1μg of Cr (VI).
NOTE 1: This solution can be stored at 0 ℃ ~ 4 ℃ for 1 week; and return to room temperature before
use.
NOTE 2: It can directly use the commercially available standard solution to prepare Cr (VI) standard
solution (0.1μg/mL).
6 Apparatus
6.1 Ion chromatograph
With ultraviolet visible (UV-Vis) detector or diode array (DAD) detector and post-column
derivatization device.
6.2 Electronic balance
The accuracy is 0.1mg.
6.3 pH meter
The accuracy is ±0.02 pH units.
7 Classification of Toy Materials
The toy materials can be divided into three categories.
--- Category-1: dry, brittle, powdery or pliable toy materials. Such materials refer to
powdered materials that are released during play. These powdered materials can get on
hands and may be swallowed.
--- Category-2: liquid or sticky toy material. Such materials are fluid or sticky materials that
may be ingested into the body or come into contact with the skin during play.
--- Category-3: scratchable toy materials. Such materials refer to solid materials, whether
coated or not, that can be ingested into the body during play, by biting, tearing with teeth,
sucking or licking.
standard method for quantification.
If the mass concentration of Cr (Ⅵ) in the specimen solution exceeds the maximum mass
concentration of the standard curve, it shall be properly diluted with ammonium chloride
solution (5.6) before determination.
12 Blank Test
Blank test does not add sample; take the same amounts of all reagents; and use the same analysis
procedures; it shall be determined in parallel with the sample.
13 Calculation of Results
The migratable Cr (VI) content in the specimen is calculated by mass fraction w; and the value
is expressed in milligrams per kilogram (mg/kg), which shall be calculated according to
Formula (1):
Where:
w – the migratable Cr (VI) content in the specimen, in mg/kg;
ρ1 – the on-instrument test mass concentration of Cr (VI) in the specimen solution, in µg/L;
ρ0 – the on-instrument test mass concentration of Cr (VI) in the specimen blank solution, in
µg/L;
V – volume of the added simulation liquid, in mL;
V2 － volume of migration solution after pH adjustment, in mL;
d – dilution factor (see 11.3);
m – mass of specimen, in g;
V1 – pipetting volume of migration solution, in mL.
NOTE: If the specimen mass is 10mg ~ 100mg, the migratable Cr (VI) content of the specimen shall be
calculated according to 100mg of used test specimen.
The calculation results shall be retained for 2 significant figures.
14 Mass Control
14.1 Quantification limit
The quantification limit for this method is 0.0025 mg/kg. The quantification limit for this
method is related to the equipment configuration and chromatographic conditions used in the
laboratory. The laboratory should confirm the quantification limit when using this method.
When using the test results of this method for conformity assessment, the method quantification
limit should be no greater than 50% of the limit value.
14.2 Precision
The precision test result data of this method can refer to Appendix B.
15 Test Report
The test report shall at least give the following:
a) specimen;
b) the used standard (including the year of publication or issuing);
c) results, including those covered in the Clause "Calculation of Results";
d) Details of the method used for the preparation of the test specimen (see Clause 8),
including but not limited to the following:
--- the specimen is not separated from the matrix material;
---centrifugal separation of the solids in the specimen solution prior to analysis and
testing;
--- additionally titrate hydrochloric acid to lower the pH;
--- additionally titrate ammonia water to adjust the pH;
--- the ratio of solid sample to acid extractant exceeds the range of 1:50;
e) any deviations from the specified sample preparation and extraction procedures due to
protocol or otherwise;
f) abnormal phenomena observed in the test;
g) test date;
h) quantitation limit.
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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