GB/T 40493-2021 PDF in English
GB/T 40493-2021 (GB/T40493-2021, GBT 40493-2021, GBT40493-2021)
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Determination of lead, cadmium, chromium and mercury content in the finishing material of wood-based panel
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Standards related to: GB/T 40493-2021
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GB/T 40493-2021: PDF in English (GBT 40493-2021) GB/T 40493-2021
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 79.060.01
CCS B 70
Determination of Lead, Cadmium, Chromium and Mercury
Content in the Finishing Material of Wood-based Panel
人造板饰面材料中铅, 镉, 铬, 汞
ISSUED ON: AUGUST 20, 2021
IMPLEMENTED ON: MARCH 1, 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 Method Summary ... 4
4 Reagents and Reference Materials ... 5
5 Instruments and Materials ... 9
6 Preparation of Specimens ... 10
7 Extraction ... 10
8 Determination of Extracting Solution ... 11
9 Result Calculation ... 13
10 Test Report ... 16
Appendix A (informative) Working Conditions and Parameters of Microwave Digestion
Apparatus ... 17
Appendix B (informative) Analysis Conditions of ICP Plasma Emission Spectrometer
... 18
Appendix C (informative) Analysis Conditions of Atomic Absorption
Spectrophotometer ... 19
Appendix D (informative) Analysis Conditions of Atomic Fluorescence Spectrometer
... 20
Determination of Lead, Cadmium, Chromium and Mercury
Content in the Finishing Material of Wood-based Panel
1 Scope
This document describes the method of determining the content of heavy metal elements (lead,
cadmium, chromium and mercury) in the finishing material and finishing coat of wood-based
panel using inductively coupled (ICP) plasma emission spectrometer, atomic absorption
spectrophotometer and atomic fluorescence spectrometer, etc.
This document is applicable to the determination of the content of heavy metal elements in the
finishing material and finishing coat of wood-based panel.
2 Normative References
Through the normative references in this text, the contents of the following documents
constitute indispensable clauses of this document. 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 6682 Water for Analytical Laboratory Use - Specification and Test Methods
GB/T 21191 Atomic Fluorescence Spectrometer
JJG 015 Verification Regulation for Inductively Coupled Plasma - Atomic Emission
Spectrometer
JJG 023 Verification Regulation of Atomic Absorption Spectrometer
JJG 694 Atomic Absorption Spectrophotometer
3 Method Summary
3.1 Determination of Heavy Metal Elements Content
The specimen is digested through the wet method or microwave; the heavy metal elements are
transferred to the digestion solution. Adopt the ICP plasma emission spectrometry to determine
the spectral intensity of lead, cadmium, chromium and mercury in the digestion solution.
Alternatively, adopt the flame atomic absorption spectrometry to determine the spectral
intensity of lead, cadmium and chromium in the digestion solution; adopt the hydride generator
- cold atomic absorption spectrometry or atomic fluorescence spectrometry to determine the
spectral intensity of mercury in the digestion solution. In accordance with the spectral intensity,
conduct the quantitative determination.
3.2 Determination of Soluble Heavy Metal Elements Content
Under the conditions of specified temperature and time, use hydrochloric acid of a certain
acidity to extract the soluble heavy metal elements in the specimen. Adopt the ICP plasma
emission spectrometry to determine the spectral intensity of lead, cadmium, chromium and
mercury in the extracting solution. Alternatively, adopt the flame atomic absorption
spectrometry to determine the spectral intensity of lead, cadmium and chromium in the
extracting solution; adopt the hydride generator - cold atomic absorption spectrometry or
atomic fluorescence spectrometry to determine the spectral intensity of mercury in the
extracting solution. In accordance with the spectral intensity, conduct the quantitative
determination.
4 Reagents and Reference Materials
4.1 Test Water
The water used shall reach the requirements of distilled water or deionized water with above
Grade-2 purity specified in GB/T 6682.
4.2 Hydrofluoric Acid
With premium purity.
4.3 Hydrogen Peroxide (30%)
With premium purity.
4.4 Hydrogen Peroxide Solution (0.5%)
Hydrogen peroxide 0.5% (volume fraction).
4.5 Hydrochloric Acid
Density = 1.19 g/mL, with premium purity.
4.6 Hydrochloric Acid Solution (1 mol/L)
Concentration c (HCl) = 1 mol/L.
4.7 Hydrochloric Acid Solution (0.07 mol/L)
Concentration c (HCl) = (0.07 0.005) mol/L.
4.8 Hydrochloric Acid Solution (5%)
brown volumetric flask. Use the hydrochloric acid solution (5%) (4.8) to dilute to the scale and
shake it well. In this mixed solution, the mass concentration of mercury is 100 g/L. Then, use
the hydrochloric acid solution (5%) (4.8) to stepwise dilute it to obtain a mixed standard
working solution with the mass concentrations of 25.0 g/L, 10.0 g/L, 5.0 g/L, 2.5 g/L, 1.0
g/L and 0.0 g/L.
5 Instruments and Materials
5.1 ICP plasma emission spectrometer: the instrument shall be able to provide a stable and clear
plasma torch; the stability of the instrument shall comply with the stipulations of JJG 015.
5.2 Atomic absorption spectrophotometer: with a continuous flow injection hydride generator,
equipped with quartz tube and lead, cadmium, chromium, mercury hollow cathode lamps; the
stability of the instrument shall comply with the stipulations of JJG 023 and JJG 694.
5.3 Atomic fluorescence spectrometer: equipped with a high-intensity mercury hollow cathode
lamp; the stability of the instrument shall comply with the stipulations of GB/T 21191.
5.4 Microwave digestion apparatus: equipped with PTFE digestion tank. Before use, the
digestion tank needs to be soaked in the nitric acid solution (4.10) for 24 h, then, washed with
water and dried.
5.5 Balance: with a division value of 0.1 mg.
5.6 Constant-temperature oscillating water bath: can maintain the temperature at (37 2) C;
the oscillation frequency is 60 times/min.
5.7 pH tester: with an accuracy of 0.1 pH unit.
5.8 Metal mesh sieve: with an aperture of 0.5 mm.
5.9 Scraper: a tool with a sharp blade, suitable for scraping the surface material of the specimen.
5.10 Mortar: before use, it needs to be washed with the nitric acid solution (4.10) and dried.
5.11 Pipette: 1 mL, 2 mL, 5 mL, 10 mL and 25 mL.
5.12 Brown volumetric flask: 25 mL, 50 mL, 100 mL and 1,000 mL. Before use, it needs to be
soaked in the nitric acid solution (4.10) for 24 h, then, washed with water and dried.
5.13 Triangular flask with a stopper: 50 mL and 100 mL. Before use, it needs to be soaked in
the nitric acid solution (4.10) for 24 h, then, washed with water and dried.
5.14 Aqueous membrane filter: with an aperture of 0.45 m.
6 Preparation of Specimens
6.1 Preparation of Finishing Material Specimens
Before specimen preparation, the impregnated adhesive film paper shall be suspended and
placed in a blast drying oven at 170 C for 15 min, then, cooled at room temperature for 1 h.
Make the impregnated adhesive film paper, thermosetting resin-impregnated paper high-
pressure decorative laminate (HPL) and polyvinyl chloride (PVC) film and other finishing
materials into a fragment with an area of less than 25 mm2. Take this fragment as a specimen;
after mixing, divide it into two equal parts; the mass of each specimen is not less than 0.5 g.
6.2 Preparation of Finishing Coat Specimen of Wood-based Panel
6.2.1 General Requirements
Dry and pollution-free finishing coat of wood-based panel shall be selected. At a distance of at
least 25 mm away from the edge, scrape the specimen from the surface.
6.2.2 Preparation of coat specimen of wood-based panel
Use a scraper to evenly scrape the surface coating of the panel and avoid scraping the fibers of
the substrate. The scraped specimen is ground with a mortar and passes through a metal sieve
with an aperture of 0.5 mm. After mixing, the specimen is divided into two equal parts; the
mass of each specimen is not less than 0.5 g.
6.2.3 Preparation of finishing coat specimen of impregnated paper wood-based panel
Use a scraper to evenly scrape the surface film adhesive layer and avoid scraping the fibers of
the substrate. The scraped specimen is ground with a mortar and passes through a metal sieve
with an aperture of 0.5 mm. After mixing, the specimen is divided into two equal parts; the
mass of each specimen is not less than 0.5 g.
6.2.4 Preparation of finishing coat specimen of polyvinyl chloride (PVC) film of wood-
based panel
Tear or use a blade to assist in removing the PVC film on the surface of the panel. Then, use
the blade to scrape off the wood fiber and colloid on the back to make a fragment with an area
of less than 25 mm2. Take this fragment as a specimen; after mixing, divide it into two equal
parts; the mass of each specimen is not less than 0.5 g.
7 Extraction
7.1 Extraction of Total Heavy Metal Elements
7.1.1 Digestion with wet method
In accordance with the requirements of 8.1.1, determine the spectral intensity of lead, cadmium,
chromium and mercury in the standard working solution (4.18.1).
In accordance with the spectral intensity of each element and the concentration parameters of
the standard working solution, respectively draw the concentration - spectral intensity linear
regression standard curve of lead, cadmium, chromium and mercury elements. The linear
correlation coefficient R2 of the standard curve shall be greater than 0.995.
8.1.3 Determination of solution
Adopt the method of 8.1.2 to respectively measure the spectral intensity of lead, cadmium,
chromium and mercury in the blank solution and the extracting solution.
8.2 Determination of Lead, Cadmium and Chromium Content in Extracting
Solution through Atomic Absorption Spectrometry
8.2.1 Determination conditions of instrument
In accordance with the operation manual of the atomic absorption spectrometer, set the analysis
parameters. The typical analysis parameters are shown in Appendix C.
8.2.2 Drawing of standard curve
In accordance with the requirements of 8.2.1, determine the absorbance of lead, cadmium and
chromium in the standard working solution (4.18.2).
In accordance with the absorbance of each element and the concentration parameters of the
standard solution, respectively draw the concentration - absorbance linear regression standard
curve of lead, cadmium and chromium elements. The linear correlation coefficient R2 of the
standard curve shall be greater than 0.995.
8.2.3 Determination of solution
Respectively introduce the blank solution and the extracting solution into the atomic absorption
spectrometer. Adopt the method of 8.2.2 to respectively determine the absorbance of lead,
cadmium and chromium in the blank solution and the extracting solution.
8.3 Determination of Mercury Content in Extracting Solution through Hydride
Generator - Cold Atomic Absorption Spectrometry
8.3.1 Drawing of standard curve
In accordance with the operation manual of the hydride generator - cold atomic absorption
spectrometer, set the analysis parameters. Continuously introduce the mercury element standard
working solution into the hydride generator system. Use hydrochloric acid solution (5%) (4.8)
as the carrier liquid and 20 g/L potassium borohydride mixed solution (4.15) as the reducing
agent. At 253.7 nm, use the mercury hollow cathode lamp to determine the absorbance of
mercury element.
In accordance with the absorbance of mercury element and the concentration parameter of the
mercury element standard working solution, draw the concentration - absorbance linear
regression standard curve of mercury. The linear correlation coefficient R2 of the standard curve
shall be greater than 0.995.
8.3.2 Determination of solution
Respectively introduce the blank solution and extracting solution into the hydride generator
system. Adopt the method of 8.3.1 to respectively determine the absorbance of mercury element
in the blank solution and the extracting solution.
8.4 Determination of Mercury Content in Extracting Solution through Atomic
Fluorescence Spectrometry
8.4.1 Determination conditions of instrument
In accordance with the operation manual of the atomic fluorescence spectrometer, set the
analysis parameters. The typical analysis parameters are shown in Appendix D.
8.4.2 Drawing of standard curve
In accordance with the requirements of 8.4.1, continuously introduce the mercury element
standard working solution into the atomic fluorescence spectrometer. Use hydrochloric acid
solution (5%) (4.8) as the carrier liquid and 20 g/L potassium borohydride mixed solution (4.15)
as the reducing agent; determine the fluorescence intensity of mercury element in the standard
working solution.
In accordance with the fluorescence intensity of mercury element and the concentration
parameter of the mercury element standard working solution, draw the concentration -
fluorescence intensity linear regression standard curve of mercury. The linear correlation
coefficient R2 of the standard curve shall be greater than 0.995.
8.4.3 Determination of solution
Adopt the method of 8.4.2 to respectively determine the fluorescence intensity of mercury
element in the blank solution and the extracting solution.
9 Result Calculation
9.1 Result Expression of Content of Heavy Metal Elements
9.1.1 The content of lead, cadmium, chromium and mercury in the extracting solution and the
blank solution shall be calculated in accordance with Formula (1), and accurate to 0.01 mg/L:
Ai---the absorbance, or fluorescence intensity, or spectral intensity of soluble heavy metal lead,
cadmium, chromium or mercury;
Bi---the standard curve intercept of lead, cadmium, chromium or mercury, expressed in (g/L).
9.2.2 The content of soluble heavy metal lead, cadmium, chromium and mercury in the
specimen shall be calculated in accordance with Formula (4). Take the average value of the
results of two parallel tests as the determined value, which shall be accurate to 0.01 mg/kg:
Where,
mi---the content of soluble heavy metal lead, cadmium, chromium and mercury elements in the
specimen, expressed in (mg/kg);
i---the mass concentration of lead, cadmium, chromium or mercury in the extracting solution,
expressed in (mg/L);
i0---the mass concentration of lead, cadmium, chromium or mercury in the blank solution (0.07
mol/L or 1 mol/L hydrochloric acid solution), expressed in (mg/L);
V---the total volume of hydrochloric acid solution added to the 50 mL conical flask, expressed
in (mL);
F---the dilution ratio of the extracting solution;
M---the mass of the specimen taken, expressed in (g).
9.2.3 Result representation
The content of soluble elements in the finishing material shall take the corrected value of the
analysis result as the final test result. The corrected value shall be calculated in accordance with
Formula (5), and accurate to 0.01 mg/kg:
Where,
m---the content of a certain soluble heavy metal element in the sample, expressed in (mg/kg);
mi---the content of soluble heavy metal elements lead, cadmium, chromium and mercury in the
specimen, expressed in (mg/kg);
Fi---the analysis correction factor, see Table 3.
Table 3 -- Analysis Correction Factor of Soluble Elements
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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