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GB/T 22930.1-2021 PDF in English


GB/T 22930.1-2021 (GB/T22930.1-2021, GBT 22930.1-2021, GBT22930.1-2021)
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GB/T 22930.1-2021: PDF in English (GBT 22930.1-2021)

GB/T 22930.1-2021
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 59.140.30
CCS Y 46
Partially replacing GB/T 22930-2008
Leather and Fur - Chemical Determination of Metal Content
- Part 1: Extractable Metals
(ISO 17072-1:2019 Leather - Chemical Determination of Metal Content - Part 1:
Extractable Metals, MOD)
ISSUED ON: OCTOBER 11, 2021
IMPLEMENTED ON: MAY 1, 2022
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 ... 8 
4 Principle ... 8 
5 Reagents and Materials ... 8 
6 Instruments and Equipment ... 9 
7 Sampling and Preparation of Specimens ... 10 
8 Test Procedures ... 10 
9 Calculation and Result Expression ... 12 
10 Test Report ... 14 
Appendix A (Informative) Structural Changes of this Document Compared to ISO
17072-1:2019 ... 15 
Appendix B (Informative) Technical Differences between this Document and ISO
17072-1:2019 and Causes for these Differences ... 16 
Appendix C (Normative) Preparation of Standard Solution and Standard Working
Solution of Elements to be Tested ... 20 
Appendix D (Informative) ICP-OES Element Determination Wavelengths and Inter-
element Interference ... 22 
Appendix E (Informative) ICP-MS Analytical Isotopes and Method Detection Limits
... 24 
Appendix F (Informative) AAS Element Determination Wavelengths and
Recommended Test Conditions ... 25 
Appendix G (Informative) Inter-laboratory Result Comparison and Detection Limits
... 26 
Bibliography... 28 
Introduction
During the processing of leather and fur, the traditional tanning process and the tanning agents,
dyes, auxiliaries and pigments used in the processing may result in leather, fur and their
products containing a certain amount of metal elements. In particular, heavy metals, such as:
arsenic, cadmium, chromium, mercury, lead, antimony, selenium and nickel, which can
penetrate into the human body through the immersion of perspiration through the skin, which
will severely endanger human health. Furthermore, with the continuous development of the
leather and fur industry at the current stage, people have been paying increasing attention to the
types and contents of metals that may be contained in their products, and the determination of
metal contents in leather and fur has also increasingly become the focus of product quality
control. GB/T 22930, which aims to provide a basis for the determination of metal contents in
leather and fur, is intended to be composed of two parts.
---Part 1: Extractable Metals. The purpose is to establish a method of determining 22
extractable metals in leather and fur.
---Part 2: Total Metal Content. The purpose is to establish a method of determining the
total amount of 24 metals in leather and fur.
The determination of metal content (especially some heavy metals) in leather and fur has always
been the focus of the industry. In 2008, China has issued a standard on the test methods GB/T
22930-2008 Leather and Fur - Chemical Tests - Determination of Heavy Metal Content, which
specifies the method of determining the total amount and extractable amount of 9 heavy metal
elements, such as: lead (Pb), cadmium (Cd) and nickel (Ni). It has been over a decade since
GB/T 22930-2008 was issued and implemented. During this period, with the continuous update
of leather and fur technology, and the application of various new materials, there have been an
increasing number of metal types that may exist in leather and fur, and the determination of
their contents has also attracted increasing attention. First of all, when the current national
standard of China was formulated, there was no relevant international standard. The standard
was independently formulated in combination with the actual situation in China. With the
gradual deepening of international trade, it has gradually been unable to satisfy the demands of
the industry. Secondly, the method standards regarding the determination of metal contents in
leather and fur have been internationally established. Not only are there more types of metals
that can be determined, but also the methods have been further refined. The determination of
metal contents is divided into two parts: extractable metals and total metal content, which is
more consistent with the current demands of the tests of leather and fur. In view of this, it is
indeed necessary to revise and further improve GB/T 22930, so as to continuously adapt to the
new changes of domestic and overseas products, and the new demands for product testing, and
ensure that the standards are in harmony with the development of the industry.
Leather and Fur - Chemical Determination of Metal Content
- Part 1: Extractable Metals
WARNING: the concentrated acids used in this document are all highly corrosive and /
or oxidizing liquids. If they come into contact with flammable substances, they will
increase the possibility of combustion or explosion, and cause acute or chronic health
hazards to the human body. In addition, there are also hazards to the water body. During
the test, necessary safety measures shall be taken.
1 Scope
This document describes the test methods for 22 extractable metal contents: aluminum (Al),
arsenic (As), barium (Ba), calcium (Ca), cadmium (Cd), cobalt (Co), chromium (Cr), copper
(Cu), iron (Fe), potassium (K), magnesium (Mg), lead (Pb), manganese (Mn), molybdenum
(Mo), nickel (Ni), mercury (Hg), antimony (Sb), selenium (Se), tin (Sn), titanium (Ti), zinc (Zn)
and zirconium (Zr).
This document is applicable to the determination of 22 extractable metal contents in various
types of leather and fur, as well as the determination of extractable chromium in chrome-tanned
leather.
2 Normative References
The contents of the following documents constitute indispensable clauses of this document
through the normative references in the text. In terms of references with a specified date, only
versions with a specified date are applicable to this document. In terms of references without a
specified date, the latest version (including all the modifications) is applicable to this document.
GB/T 3922 Textiles - Testing Method for Color Fastness to Perspiration (GB/T 3922-2013, ISO
105-E04:2013, MOD)
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 39364-2020, ISO 2418:2017, MOD)
QB/T 1267 Fur - Chemical, Physical and Mechanical and Fastness Tests - Sampling Location
(QB/T 1267-2012, ISO 2418:2002, MOD)
QB/T 1272 Leather - Chemical Tests - Preparation of Chemical Test Samples (QB/T 1272-2012,
ISO 4044:2008, MOD)
QB/T 1273 Fur - Chemical Tests - Determination of Volatile Matter (QB/T 1273-2012, ISO
4684:2005, MOD)
QB/T 1276 Fur - Chemical Tests - Determination of Matter Soluble in Carbon Tetrachloride
(QB/T 1276-2012, ISO 4048:2008, MOD)
QB/T 2716 Leather - Preparation of Chemical Test Samples (QB/T 2716-2018, ISO 4044:2008,
MOD)
QB/T 2717 Leather - Chemical Tests - Determination of Volatile (QB/T 2717-2018, ISO
4684:2005, MOD)
QB/T 2718 Leather - Chemical Tests - Determination of Matter Soluble in Dichloromethane
(QB/T 2718-2018, ISO 4048:2008, MOD)
3 Terms and Definitions
This document does not have terms or definitions that need to be defined.
4 Principle
Leather specimen is extracted by acidic artificial perspiration; the extract is filtered and
acidified, then, passes through inductively coupled plasma optical emission spectrometer (ICP-
OES), inductively coupled plasma mass spectrometer (ICP-MS), atomic absorption
spectrometer (AAS) or atomic fluorescence spectrometer (AFS). Determine the metal
concentration in the extract; calculate the content of extractable metals in the specimen.
NOTE: this method determines the content of extractable metals, not the content of a specific metal
compound or metal oxide.
5 Reagents and Materials
5.1 Unless it is otherwise specified, all reagents used shall be analytically pure, and the test
solutions shall be aqueous solutions.
5.2 Nitric acid, with a mass fraction of 60% ~ 70%.
5.3 L-histidine hydrochloride-hydrate, C6H9O2N3  HCl  H2O.
5.4 Sodium chloride.
5.5 Sodium dihydrogen phosphate dihydrate, NaH2PO4  2H2O.
5.6 Sodium hydroxide solution, 0.1 mol/L.
5.7 Metal element standard stock solution. The mass concentration of each metal element is
purity of the used gas shall be not less than 99.99%.
6.13 Inductively coupled plasma mass spectrometer (ICP-MS); the purity of the used gas shall
be not less than 99.99%.
6.14 Atomic fluorescence spectrometer (AFS), which is used for the determination of mercury
content.
7 Sampling and Preparation of Specimens
7.1 Sampling
Leather shall comply with the stipulations of GB/T 39364.
Fur shall comply with the stipulations of QB/T 1267.
If it is not possible to take samples from standard parts (for example, directly from shoes and
clothes), sampling shall be conducted from any part within the available area. The specimens
shall be representative, and the sampling process shall be indicated in the test report.
7.2 Preparation of Specimens
Leather shall comply with the stipulations of QB/T 2716.
Fur shall comply with the stipulations of QB/T 1272. During the shearing process, damage to
the coat shall be avoided, and the coat shall be maintained intact.
For specimens with a high moisture content (greater than 30%), they should be pre-dried at a
temperature not exceeding (50  2) C for more than 12 h. The selection of temperature during
the pre-drying should consider the possible impact of high temperature on the properties of the
substances being analyzed.
7.3 Determination of Volatiles
Leather shall comply with the stipulations of QB/T 2717. Fur shall comply with the stipulations
of QB/T 1273. Specimens prepared from the same batch may be used for the extraction in 8.2.
8 Test Procedures
8.1 Preparation of Acidic Artificial Perspiration
Comply with the stipulations of GB/T 3922. This solution shall be prepared right before use.
See the components of the solution in Table 1.
8.4.2.1 ICP-OES method
In accordance with the instruction manual of the instrument, set the parameters of ICP-OES
(6.11).
Take the metal element solution with an already-known concentration as the reference. At the
specific wavelength of each metal element, use ICP-OES to analyze the specimen extract
prepared in 8.2. The commonly selected determination wavelengths of the various metal
elements are shown in Appendix D. In accordance with the same determination conditions as
the specimen extract, analyze the blank test solution (8.3).
8.4.2.2 ICP-MS method
In accordance with the instruction manual of the instrument, set the parameters of ICP-MS
(6.13). Take the metal element solution with an already-known concentration as the reference.
At the characteristic ion mass of each metal element, use ICP-MS to analyze the specimen
extract prepared in 8.2. The commonly selected analytical isotopes and the method detection
limits of the various metal elements are shown in Appendix E. In accordance with the same
determination conditions as the specimen extract, analyze the blank test solution (8.3).
8.4.3 AAS method
In accordance with the instruction manual of the instrument, set the parameters of the atomic
absorption spectrometer (6.12).
Take the metal element solution with an already-known concentration as the reference. Use a
suitable hollow cathode lamp to analyze the metal content in the specimen extract prepared in
8.2 by AAS. The determination wavelengths and the recommended test conditions of the
various metal elements are shown in Appendix F. In accordance with the same determination
conditions as the specimen extract, analyze the blank test solution (8.3).
8.4.4 AFS method
In accordance with the instruction manual of the instrument, set the parameters of the atomic
fluorescence spectrometer (6.14).
Take mercury-containing solution with an already-known concentration as the reference. Use
AFS to analyze the mercury content in the specimen extract prepared in 8.2. In accordance with
the same determination conditions as the specimen extract, analyze the blank test solution (8.3).
9 Calculation and Result Expression
In accordance with Formula (1), calculate the mass fraction of each metal element (counted by
the dry mass of the specimen), accurate to 0.1 mg/kg:
Where,
wx---the content of extractable metals in the specimen, expressed in (mg/kg);
wx,i---the content of metal elements in the specimen extract obtained through instrumental
analysis, expressed in (mg/L);
wx,b---the content of metal elements in the blank test solution obtained through instrumental
analysis, expressed in (mg/L);
m---the mass of the specimen, expressed in (g);
V1---the volume of the acidic artificial perspiration added during extraction, expressed in (mL);
Fd---the dilution ratio during acidification (see 8.4.1);
---the content of volatiles in the specimen measured in accordance with QB/T 2717 or QB/T
1273, expressed in (%).
If necessary, in accordance with Formula (2), calculate the mass fraction (counted by the
absolute dry mass of the specimen after degreasing) of each metal element in the specimen,
which shall be indicated in the test report.
Where,
wx-d---the content of extractable metals in the specimen, expressed in (mg/kg);
wx,i---the content of metal elements in the specimen extract obtained through instrumental
analysis, expressed in (mg/L);
wx,b---the content of metal elements in the blank test solution obtained through instrumental
analysis, expressed in (mg/L);
m---the mass of the specimen, expressed in (g);
V1---the volume of the acidic artificial perspiration added during extraction, expressed in (mL);
Fd---the dilution ratio during acidification (see 8.4.1);
A---the grease content in the specimen measured in accordance with QB/T 2718 or QB/T 1276,
expressed in (%).
The statistical evaluation of inter-laboratory test results of lead content is shown in Table G.1
in Appendix G; the detection limits of ICP-OES method are shown in Table G.2.
Appendix C
(Normative)
Preparation of Standard Solution and Standard Working Solution of Elements to be
Tested
C.1 Overall Requirements
In accordance with different ranges of determination, different element standard solutions may
be required. Under general circumstances, when preparing a multi-element mixed standard
solution, pay attention to its chemical compatibility and possible hydrolysis of its components,
so as to prevent chemical reactions (for example, precipitation) and spectral interference. In
order to avoid interference, digestion reagents (such as: nitric acid, sulfuric acid and aqua regia,
etc.) may be added to the mixed standard solution.
The formulations provided below also take into account the different sensitivities of different
spectrometers.
The multi-element mixed standard solution usually has a shelf life of several months when
stored in the dark.
C.2 Preparation of Metal Element Standard Solution
C.2.1 Multi-element mixed standard solution A
 (Al, Cd, Co, Cr, Cu, Fe, Pb, Mn, Mo, Ni, Zn, Zr) = 1 mg/L.
Transfer about 250 mL of water (5.8) to a 1,000 mL volumetric flask (6.7); add 5 mL of nitric
acid (5.2); accurately transfer-take 1 mL of the metal element (Al, Cd, Co, Cr, Cu, Fe, Pb, Mn,
Mo, Ni, Zn, Zr) standard stock solution (5.7) to the volumetric flask. Use water to dilute to a
constant volume to the scale, then, transfer into a suitable storage bottle.
C.2.2 Multi-element mixed standard solution B
 (Sn, Ti, As, Se, Sb) = 10 mg/L.
Transfer about 250 mL of water (5.8) to a 1,000 mL volumetric flask (6.7); add 5 mL of
hydrochloric acid (5.10); accurately transfer-take 10 mL of the metal element (Sn, Ti, As, Se,
Sb) standard stock solution (5.7) into the volumetric flask. Use water to dilute to a constant
volume to the scale, then, transfer into a suitable storage bottle.
C.2.3 Multi-element mixed standard solution C
 (Ca, Mg, K) = 100 mg/L.
Accurately transfer-take 100 mL of the metal element (Ca, Mg, K) standard stock solution (5.7)
into a 1,000 mL volumetric flask (6.7). Add 5 mL of nitric acid (5.2). Use water to dilute to a
constant volume to the scale, then, transfer into a suitable storage bottle.
C.2.4 Barium standard solution D
 (Ba) = 0.1 mg/L.
Transfer about 250 mL of water (5.8) to a 1,000 mL volumetric flask (6.7); add 5 mL of nitric
acid (5.2); accurately transfer-take 0.1 mL of the metal element (Ba) standard stock solution
(5.7) to the volumetric flask. Use water to dilute to a constant volume to the scale, then, transfer
into a suitable storage bottle.
NOTE: since Ba may precipitate under certain circumstances, a single-element standard solution
is prepared during the determination.
C.2.5 Mercury standard solution E
 (Hg) = 1 mg/L.
Accurately transfer-take 1 mL of the metal element (Hg) standard stock solution (5.7) to a 1,000
mL volumetric flask; add 5 mL of nitric acid (5.2). Use water to dilute to a constant volume to
the scale, then, transfer into a suitable storage bottle.
C.3 Preparation of Metal Element Standard Working Solution
In accordance with the actual demands, dilute the metal element standard solution (C.2) step-
by-step to prepare the metal element standard working solution with a series of concentrations.
The shelf life of the standard working solution with concentrations below 1 mg/L and 100 g/L
respectively should not exceed 1 month and 1 day.
Example: respectively transfer-take 200 L, 400 L, 600 L, 800 L and 1,000 L of the multi-
element mixed standard solution A (C.2.1) in a 100 mL volumetric flask; use water to
dilute to a constant volume; prepare the metal element standard working solution
respectively with concentrations 2 g/L, 4 g/L, 6 g/L, 8 g/L and 10 g/L.
......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.