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GB 18582-2001 Limits of harmful substances in interior wall coatings for interior decoration materials

Basic Information

Standard ID: GB 18582-2001

Standard Name: Limits of harmful substances in interior wall coatings for interior decoration materials

Chinese Name: 室内装饰装修材料 内墙涂料中有害物质限量

Standard category:National Standard (GB)

state:Abolished

Date of Release2001-01-02

Date of Implementation:2002-01-01

Date of Expiration:2008-10-01

standard classification number

Standard ICS number:Paint and pigment industry >> 87.040 Paints and varnishes

Standard Classification Number:Chemicals>>Coatings, Pigments, Dyes>>G51 Coating

associated standards

alternative situation:Replaced by GB 18582-2008

Procurement status:EC/10-1990,≠ BS 5665-1989,≠ DIN EN 71-1989,≠ NF EN 71-3,≠ EN 71-1988,≠

Publication information

publishing house:China Standards Press

ISBN:155066.1-18137

Publication date:2004-04-17

other information

Release date:2001-12-10

Review date:2004-10-14

Drafting unit:China National Chemical Engineering Corporation

Focal point unit:National Technical Committee for Standardization of Paints and Pigments

Publishing department:General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China

competent authority:China Petroleum and Chemical Industry Association

Introduction to standards:

This standard specifies the technical requirements, test methods, inspection rules, packaging marks, safe coating and protection for the permissible limits of harmful substances in wall coatings for indoor decoration. This standard applies to water-based wall coatings for indoor decoration. This standard does not apply to interior wall coatings that use organic matter as solvents. GB 18582-2001 Limits of harmful substances in interior wall coatings for indoor decoration materials GB18582-2001 Standard download decompression password: www.bzxz.net

Some standard content:

ICS87.040bZxz.net
National Standard of the People's Republic of China
GB 18582—2001
Indoor decorating and refurbishing materials
Limit of harmful substances of interior architectural coatingsIssued on 2001-12-10
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
Implementation on 2002-01-01
GB18582—2001
Chapter 3 of this standard is mandatory and the rest are recommended. The volatile organic compound (VOC) limit values ​​in this standard refer to the ecological standard for paints and varnishes (1999/10/EC), the ecological standard for soluble heavy metals, and the requirements of the United Kingdom, Germany, France and the European Economic Commission for toxic heavy metals in children's toy materials (BS5665: 1989, DINEN711989, NFEN71-3, EN71: 1988). Appendix A, Appendix B and Appendix C of this standard are normative appendices. From January 1, 2002, the products produced by the manufacturers shall comply with this national standard, with a transition period of 6 months; from July 1, 2002, the products that do not meet this national standard shall be stopped from being sold on the market. This standard is proposed by the China Petroleum and Chemical Industry Association. This standard is under the jurisdiction of the National Technical Committee for Standardization of Paints and Pigments. The drafting organizations of this standard are: Changzhou Paint Chemical Research Institute of China National Chemical Construction Corporation, Institute of Environmental Health Monitoring of Chinese Academy of Preventive Medicine, Shanghai Paint Co., Ltd., Shanghai Paint Research Institute, Sinochem Chemical Standardization Institute, China Paint Industry Association, China Building Materials Research Institute, China Academy of Building Research.
Participating organizations of this standard are: Shanghai Huasheng Chemical Co., Ltd., Nanjing Huacai Special Paint Factory, Fust Paint (Beijing) Co., Ltd., Shanghai COSCO Huili Paint Co., Ltd., Nippon Paint (China) Co., Ltd., Brunner Man Swire Paints (China) Co., Ltd., Zhejiang Tiannv Group Paint Co., Ltd., Shanghai Feihu Architectural Paint Co., Ltd., Shanghai Academy of Building Research, Changzhou Monkey King Paint Co., Ltd., Beijing Fuye Paint Co., Ltd.
Main drafters of this standard are: Zhang Junzhi, Zhao Ling, Feng Shifang, Qi Qiping, Wu Guolin, Xu Dongqun, Wang Daozhang, Mei Jian, Huang Tianyuan, Wang Jing, Xiong Wei.
This standard was first issued on December 10, 2001. This standard is entrusted to the National Technical Committee for Standardization of Paints and Pigments for interpretation.
1 Scope
GB18582—2001
Indoor decoration materials
Limits of harmful substances in interior wall paints
This standard specifies the technical requirements, test methods, inspection rules, packaging marks, safe coating and protection for the permissible limits of harmful substances in wall paints for indoor decoration. This standard applies to water-based wall paints for indoor decoration. This standard does not apply to interior wall paints with organic substances as solvents 1) 2 Normative references
The clauses in the following documents become clauses of this standard through reference in this standard. For dated references, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties to an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For undated references, the latest versions apply to this standard. GB/T1250—1989 Methods for expressing and determining limit values ​​GB3186—1982 (1989) Sampling of coating products (neqISO1512:1974) GB/T6682—1992 Specifications and test methods for water used in analytical laboratories (neqISO3696:1987) GB/T6750—1986 Determination of density of paints and varnishes (eqvIS02811:1974) GB/T6751—1986 Determination of density of paints and varnishes (eqvIS02811:1974) —1986 Determination of volatile and non-volatile matter in paints and varnishes (eqvISO15151973) GB/T9750—1998 Labelling of coating product packaging GB/T9758.1—1988 Determination of "soluble" metal content in paints and varnishes Part 1: Determination of lead content Flame atomic absorption spectrometry and dithiothreitol spectrophotometry (idtIS03856.1:1984) GB/T9758.4—1988
Paints Determination of the "soluble" metal content of paints and varnishes Part 4: Determination of cadmium content Flame atomic absorption spectrometry and polarography (idtISO3856.4:1984) GB/T9758.6—1988
GB/T9758.7—1988
3 Requirements
Determination of the "soluble" metal content of paints and varnishes Part 6: Determination of the total chromium content in the liquid part of the paint Flame atomic absorption spectrometry (idtIS 03856.61984) Determination of "soluble" metal content of paints and varnishes Part 7: Determination of mercury content in the pigment part of paints and the liquid part of water-reducible paints Flameless atomic absorption spectrometry (idtISO
3856.7:1984)
The product should meet the technical requirements of Table 1:
1) Interior wall paints with organic matter as solvents can refer to the "Limits of Hazardous Substances in Solvent-based Wood Coatings for Interior Decoration and Renovation Materials". 1
Volatile organic compounds (VOC)/(g/L)Free formaldehyde/(g/kg)
Heavy metals/(mg/kg)
4 Test methods
4.1 Sampling
GB18582—2001
Table 1 Technical requirements
Soluble lead
Soluble cadmium
Soluble chromium
Soluble mercury
Limit value
The product is sampled in accordance with the provisions of GB3186-1982 (1989). The sample is divided into two parts, one is sealed and stored, and the other is used as a test sample.
4.2 The determination of volatile organic compounds (VOC) shall be carried out in accordance with Appendix A. 4.3 The determination of free formaldehyde shall be carried out in accordance with Appendix B. 4.4 The determination of heavy metals (soluble lead, soluble cadmium, soluble chromium, soluble mercury) shall be carried out in accordance with Appendix C. 5 Inspection rules
5.1 All technical requirements listed in this standard are type inspection items. 5.1.1 Under normal production conditions, type inspection shall be carried out at least once a year. 5.1.2 Type inspection shall be carried out at any time in the following circumstances: when a new product is initially finalized;
-When the product is produced in a different place,
When there are major changes in the production formula, process and raw materials; when production is resumed after a three-month suspension.
5.2 Determination of inspection results
5.2.1 The inspection results shall be determined in accordance with the rounded value comparison method in GB/T12501989. 5.2.2 When the inspection results of all items meet the technical requirements of this standard, the product meets the requirements of this standard. If one of the test results does not meet the requirements of this standard, the preserved sample shall be retested. If the retest result still does not meet the requirements of this standard, the product does not meet the requirements of this standard.
6 Packaging mark
In addition to complying with the provisions of GB/T97501998, the product packaging mark that passes the inspection according to this standard can be clearly indicated on the packaging mark.
7 Safe painting and protection
7.1 Ensure that the room is well ventilated during painting. 7.2 Brushing should be used as much as possible.
7.3 Construction workers should wear necessary protective equipment during painting. 7.4 Continue to keep the indoor air ventilated after painting. 7.5 Ensure that the room after painting is vacant for a period of time before moving in. 2
A.1 Principle
GB18582—2001
Appendix A
(Normative Appendix)
Determination of Volatile Organic Compounds (VOC)
The total volatile content in the coating minus the water content is the volatile organic compound content in the coating. A.2 Determination of Total Volatile Content (V)
After stirring the sample evenly, determine the total volatile mass fraction (V) in the coating according to GB/T6751-1986. Test conditions: (105±2)℃, keep for 3h.
A.3 Determination of moisture content (VH,o)
A.3.1 Gas chromatography
A.3.1.1 Reagents
A.3.1.1.1 Distilled water (GB/T6682, grade 3 water); A.3.1.1.2 Anhydrous dimethylformamide (DMF), analytical grade A.3.1.1.3 Anhydrous isopropanol, analytical grade. A.3.1.2 Instruments
A.3.1.2.1 Gas chromatograph: equipped with thermal conductivity detector. A.3.1.2.2 Chromatographic column: 1mm in length, 3.2mm in outer diameter, stainless steel column filled with 177um250μm polymer porous microspheres. (For programmed temperature rise, the initial column temperature is 80℃, maintained for 5min, the rate of increase is 30℃/min, the final temperature is 170℃, maintained for 5min; for constant temperature, the column temperature is 140℃, after the isopropanol is completely discharged, the column temperature is adjusted to 170℃, and the DMF peak is discharged. If the test is to be continued, the column temperature is lowered to 140℃c).
A.3.1.2.3 Recorder.
A.3.1.2.4 Micro-syringe: 1μL or 20μL. A.3.1.2.5 Stoppered glass bottle: 10mL.
A.3.1.3 Test steps
A.3.1.3.1 Determination of the response factor R of water
Weigh about 0.2g of distilled water and about 0.2g of isopropanol in the same stoppered glass bottle, accurate to 0.1mg, add 2mL of dimethylformamide and mix. Use a microsyringe to inject 1μL of the standard mixed sample and record its chromatogram. Calculate the response factor R of water according to the following formula:
W,AH2o
R=WhoAi
W——mass of isopropanol, in grams (g); Wh,o——mass of water, in grams (g); AH,o——water peak area,
A; isopropanol peak area.
. (A.1)
If isopropyl alcohol and dimethylformamide are not anhydrous reagents, use the same amount of isopropyl alcohol and dimethylformamide (mixed solution) but without adding water as blank, and record the water peak area of ​​blank. 3
Calculate the response factor of water according to the following formula:
W,——mass of isopropyl alcohol, in grams (g); WHz0——mass of water, in grams (g); Ai——peak area of ​​isopropyl alcohol,
AHzo——peak area of ​​water;
B——peak area of ​​water in blank.
A.3.1.3.2 Sample analysis
GB18582—2001
WI(AH,O-B)
Weigh 0.6g of the stirred sample and 0.2g of isopropanol, accurate to 0.1mg, and add them to a stoppered glass bottle. Then add 2mL of dimethylformamide and cover the bottle stopper. At the same time, prepare a blank sample of isopropanol and dimethylformamide without coating. Shake the vial containing the sample vigorously for 15min, let it stand for 5min to precipitate, or use a low-speed centrifuge to precipitate it. Pipette 1μL of the supernatant in the sample bottle, inject it into the chromatograph, and record its chromatogram. Calculate the mass fraction of water in the coating VH,o (%) according to the following formula: VHo
W—Water peak area;
B—Water peak area in blank;
A—Isopropanol peak area;
W—Isopropanol mass, in grams (g); W—Coating mass, in grams (g);
R—Response factor.
A.3.2 Karl Fischer method (Karl Fischer) A.3.2.1 Reagents
A.3.2.1.1 Distilled water (GB/T6682, third-grade water); (AH20-B) W.×100
. (A.3)
A.3.2.1.2 Karl Fischer reagent: Select appropriate reagent (for samples without aldehydes and ketones, the main components of the reagent are iodine, sulfur dioxide, methanol, and organic base. For samples containing aldehydes and ketones, special reagents for aldehydes and ketones should be used, and the main components of the reagent are iodine, imidazole, sulfur dioxide, 2-methoxyethanol, 2-chloroethanol and chloroform). A.3.2.2 Instruments
A.3.2.2.1 KarlFischer moisture titrator A.3.2.2.2 Syringe: 10μL;
A.3.2.2.3 Disposable dropper: 3mL.
A.3.2.3 Test steps
A.3.2.3.1 Calibration of KarlFischer reagent Add new solvent to the titration bottle to cover the electrode end, and titrate to the end point with KarlFischer reagent. Use a 10μL syringe to draw in distilled water, inject it into the titration bottle, weigh the mass of water by reduction method, accurate to 0.1mg, and enter the mass of water into the titrator. Titrate to the end point with KarlFischer reagent and record the calibration result displayed on the instrument. Repeat the calibration until the difference between the calibration values ​​of two adjacent times is less than 1%, calculate the average value of at least two measurements, and enter the average value of the calibration result into the titrator.
A.3.2.3.2 Sample analysis
GB18582—2001
Use a disposable dropper to take a paint sample, add 1 to 2 drops to the titration bottle, weigh the added paint mass by the reduction method, accurate to 0.1 mg, and input the paint mass into the titrator. Titrate the sample to the endpoint with KarlFischer reagent and record the measurement results displayed by the instrument.
Repeat the measurement. The relative deviation of the two analysis results obtained by the same analyst shall not exceed 3.5%. A.4 Determination of density (p)
After stirring the sample evenly, determine the paint density (p) according to GB/T6750—1986, and the test temperature is (23±2)℃. A.5 Calculation of Volatile Organic Compound Content (VOC) Volatile organic compound content (VoC) is calculated by the following formula: VoC = (V-VH,o)XpX103
Wherein:
VOC---Volatile organic compound content in coating, in grams per liter (g/L); V---mass fraction of total volatiles in coating; VH,o---mass fraction of water in coating; p---density of coating at (23±2)℃, in grams per milliliter (g/mL). (A.4)
B.1 Principle
GB18582-2001
Appendix B
(Normative Appendix)
Determination of free formaldehyde
Take a certain amount of sample, distill it, dilute the obtained fraction in a certain proportion, and then use acetylacetone for color development. The solution after color development is used to determine the formaldehyde content by colorimetric analysis with a spectrophotometer.
B.2 Scope of application
This method is applicable to coatings with a free formaldehyde content of (5X10-3~0.5) g/kg. Coatings with a content exceeding this can be measured by this method after appropriate dilution.
B.3 Reagents
All reagents used are analytically pure, and the water used meets the requirements of grade 3 water in GB/T6682-1992. B.3.1 Acetylacetone solution: weigh 25g of ammonium acetate, add 50mL of water to dissolve, add 3mL of glacial acetic acid and 0.5mL of distilled acetone reagent, transfer to a 100mL volumetric flask, and dilute to the scale. The storage period is no more than 14 days. B.3.2 Formaldehyde: The concentration is about 37%.
B.4 Instruments
B.4.1 Distillation apparatus: 500mL distillation flask, serpentine condenser, fraction receiver blood: B.4.2 Volumetric flasks: 100mL, 250mL, 1000mL; B.4.3 Pipette: 1mL, 5mL, 10mL, 15mL, 20mL, 25mL; B.4.4 Water bath;
5 Balance: accuracy 0.001g
610mm absorption cell;
B.4.7 Spectrophotometer.
B.5 Test steps
B.5.1 Preparation of formaldehyde standard solution and drawing of standard working curve B.5.1.1 Preparation of 1mg/mL formaldehyde solution: Take 2.8mL formaldehyde (concentration of about 37%), dilute to 1000mL with water, determine the precise concentration of formaldehyde solution by iodine titration method, and use it to prepare standard dilution solution. B.5.1.2 Preparation of 10μg/mL standard diluent: Before use, take about 10mL of the formaldehyde solution prepared and calibrated according to B.5.1.1, dilute to 1000mL, and prepare a 10μg/mL standard diluent. B.5.1.3 Preparation of formaldehyde standard solution: Take 10ug/mL standard diluent according to the following regulations, dilute to 100mL and prepare the formaldehyde standard solution, see Table B.1.
Sampling volume/mL
(10μg/mL standard diluent)
B.5.1.4 Drawing of standard working curve
GB18582—2001
Table B.1 Preparation of formaldehyde standard solution
Formaldehyde concentration after dilution/(ug/mL)
Pipette 5mL of each solution according to B.5.1.3. Add 1 mL of acetylacetone solution to each of the prepared formaldehyde standard solutions, heat in a boiling water bath at 100°C for 3 min, and after cooling to room temperature, use a 10 mm absorption cell (with water as reference) to measure the absorbance at a wavelength of 412 nm on a spectrophotometer.
Use the formaldehyde content in 5 mL of formaldehyde standard solution as the abscissa and the absorbance as the ordinate to draw a standard working curve. Calculate the slope of the regression line, and use the reciprocal of the slope as the calculation factor for sample determination. BB.5.2 Sample treatment
Weigh 2 g of the stirred sample and place it in a distillation flask that has been pre-added with 50 mL of water. Gently shake the spoon and add 200 mL of water. Pre-add an appropriate amount of water to the fraction receiving vessel to immerse the fraction outlet, and cool the outside of the fraction receiving vessel with ice (see Figure B.1 for the distillation device). Heat and distill, collect 200 mL of fraction, remove the fraction receiving vessel, and dilute the fraction to 250 mL. The absorbance of the distilled fraction should be measured within 6 hours.
1—distillation flask, 2—heating device, 3—lifting platform, 4—condenser, 5—connection receiving device Figure B.1 Schematic diagram of distillation device
B.5.3 Determination of formaldehyde content
Take 5mL of the distilled fraction after volume adjustment from the volumetric flask in B.5.2, add 1mL of acetylacetone solution, and measure the absorbance according to the conditions of B.5.1.4.
Take 5mL of water and add 1mL of acetylacetone solution, and perform a blank test under the same conditions. The absorbance of the blank test should be less than 0.01, otherwise the acetylacetone solution should be re-prepared. 7
Calculation of results
The free formaldehyde content is calculated according to the following formula:
W——free formaldehyde content, in grams per kilogram (g/kg);A—absorbance of sample solution;
Ao—absorbance of blank solution;
B,——calculation factor;
m—sample size, in grams (g);
0.05——conversion coefficient.
..--.++-..++...(B. l )
c.1 Principle
GB18582—2001
Appendix C
(Normative Appendix)
Determination of heavy metals (soluble lead, soluble lead, soluble chromium and soluble mercury) The coating film was treated with 0.07mol/L dilute hydrochloric acid, and the metal element content in the solution was determined by flame atomic absorption spectrometry or flameless atomic absorption spectrometry.
c.2 Reagents
All reagents used were analytically pure, and the water used met the requirements of grade 3 water in GB/T6682-1992. C.2.1 Hydrochloric acid solution: 0.07mol/L, 1mol/L, 2mol/L; C.2.2 Nitric acid solution: 65%~68% (mass fraction). C.3 Instruments
c.3.1 Stainless steel metal sieve: pore size 0.5mm. C.3.2 Acidity meter: accuracy is ±0.2 pH unit. C.3.3 Membrane filter: pore size 0.45um.
C.3.4 Magnetic stirrer: the outer layer of the stirrer should be plastic or glass. C.3.5 Single-scale pipette: 25mL.
C.4 Test steps
C.4.1 Coating preparation
After stirring the sample evenly, prepare the coating on the glass plate (which needs to be soaked in 1:1 nitric acid aqueous solution for 24 hours, cleaned and dried) according to the requirements of the coating product. After it is completely dried, take the sample (if dried, the temperature must not exceed 60℃), crush it at room temperature, and sieve it through a 0.5mm metal sieve for processing.
Note: If the coating is not easy to crush into 0.5mm, the sample can be directly processed without sieving. C.4.2 Sample treatment
Weigh 0.5g (accurate to 0.0001g) of the crushed and sieved sample, add 25mL of 0.07mol/L hydrochloric acid solution, mix, stir for 1min, measure its acidity, if pH>1.5, gradually add 2mol/L hydrochloric acid solution and shake well to make the pH between 1.0 and 1.5. Stir the mixed solution continuously at room temperature for 1h, then let it stand for 1h, filter it immediately with a membrane filter and store it away from light. The test should be completed within 4h. If the test cannot be completed within 4h, add 25mL of 1mol/L hydrochloric acid solution to treat the sample, and the treatment method is the same as above. C.4.3 Determination
C.4.3.1 The determination of soluble lead content shall be carried out in accordance with Chapter 3 of GB/T9758.1-1988. C.4.3.2 The determination of soluble cadmium content shall be carried out in accordance with Chapter 3 of GB/T9758.4-1988. C.4.3.3 The determination of soluble chromium content shall be carried out in accordance with GB/T9758.6-1988. C.4.3.4 The determination of soluble mercury content shall be carried out in accordance with GB/T9758.7-1988. C.5 Calculation of results
The content of heavy metals is calculated by the following formula:
c= (ar-α) × 25 × F
Wherein:
GB18582-2001
(lead, cadmium, chromium, mercury) soluble content, in milligrams per kilogram (mg/kg); -0.07mol or 1mol hydrochloric acid solution blank concentration, in micrograms per milliliter (ug/mL); ao
a1——the concentration of the test solution (lead, cadmium, chromium, mercury) measured from the standard curve, in micrograms per milliliter (ug/mL); F——dilution factor;
25——the volume of hydrochloric acid extracted, in milliliters (mL); m
——the amount of sample weighed, in grams (g). 101 Coating preparation
After stirring the sample evenly, prepare the coating on the glass plate (which needs to be soaked in 1:1 nitric acid aqueous solution for 24 hours, cleaned and dried) according to the requirements of the coating product. After it is completely dried, take the sample (if it is dried, the temperature must not exceed 60℃), crush it at room temperature, and sieve it through a 0.5mm metal sieve for processing.
Note: If the coating is not easy to crush into 0.5mm, the sample can be processed directly without sieving. C.4.2 Sample processing
Weigh 0.5g (accurate to 0.0001g) of the crushed and sieved sample, add 25mL0.07mol/L hydrochloric acid solution, mix, stir for 1min, and measure its acidity. If pH>1.5, gradually add 2mol/L hydrochloric acid solution and shake well to make the pH between 1.0 and 1.5. Stir the mixture continuously at room temperature for 1h, then let it stand for 1h, filter it with a membrane filter immediately and store it in the dark. The test should be completed within 4h. If the test cannot be completed within 4 hours, 25 mL of 1 mol/L hydrochloric acid solution shall be added to treat the sample in the same manner as above. C.4.3 Determination
C.4.3.1 The determination of soluble lead content shall be carried out in accordance with Chapter 3 of GB/T9758.1-1988. C.4.3.2 The determination of soluble cadmium content shall be carried out in accordance with Chapter 3 of GB/T9758.4-1988. C.4.3.3 The determination of soluble chromium content shall be carried out in accordance with GB/T9758.6-1988. C.4.3.4 The determination of soluble mercury content shall be carried out in accordance with GB/T9758.7-1988. C.5 Calculation of results
The content of heavy metals is calculated by the following formula:
c= (ar-α) × 25 × F
Wherein:
GB18582-2001
(lead, cadmium, chromium, mercury) soluble content, in milligrams per kilogram (mg/kg); -0.07mol or 1mol hydrochloric acid solution blank concentration, in micrograms per milliliter (ug/mL); ao
a1——the concentration of the test solution (lead, cadmium, chromium, mercury) measured from the standard curve, in micrograms per milliliter (ug/mL); F——dilution factor;
25——the volume of hydrochloric acid extracted, in milliliters (mL); m
——the amount of sample weighed, in grams (g). 101 Coating preparation
After stirring the sample evenly, prepare the coating on the glass plate (which needs to be soaked in 1:1 nitric acid aqueous solution for 24 hours, cleaned and dried) according to the requirements of the coating product. After it is completely dried, take the sample (if it is dried, the temperature must not exceed 60℃), crush it at room temperature, and sieve it through a 0.5mm metal sieve for processing.
Note: If the coating is not easy to crush into 0.5mm, the sample can be processed directly without sieving. C.4.2 Sample processing
Weigh 0.5g (accurate to 0.0001g) of the crushed and sieved sample, add 25mL0.07mol/L hydrochloric acid solution, mix, stir for 1min, and measure its acidity. If pH>1.5, gradually add 2mol/L hydrochloric acid solution and shake well to make the pH between 1.0 and 1.5. Stir the mixture continuously at room temperature for 1h, then let it stand for 1h, filter it with a membrane filter immediately and store it in the dark. The test should be completed within 4h. If the test cannot be completed within 4 hours, 25 mL of 1 mol/L hydrochloric acid solution shall be added to treat the sample in the same manner as above. C.4.3 Determination
C.4.3.1 The determination of soluble lead content shall be carried out in accordance with Chapter 3 of GB/T9758.1-1988. C.4.3.2 The determination of soluble cadmium content shall be carried out in accordance with Chapter 3 of GB/T9758.4-1988. C.4.3.3 The determination of soluble chromium content shall be carried out in accordance with GB/T9758.6-1988. C.4.3.4 The determination of soluble mercury content shall be carried out in accordance with GB/T9758.7-1988. C.5 Calculation of results
The content of heavy metals is calculated by the following formula:
c= (ar-α) × 25 × F
Wherein:
GB18582-2001
(lead, cadmium, chromium, mercury) soluble content, in milligrams per kilogram (mg/kg); -0.07mol or 1mol hydrochloric acid solution blank concentration, in micrograms per milliliter (ug/mL); ao
a1——the concentration of the test solution (lead, cadmium, chromium, mercury) measured from the standard curve, in micrograms per milliliter (ug/mL); F——dilution factor;
25——the volume of hydrochloric acid extracted, in milliliters (mL); m
——the amount of sample weighed, in grams (g). 10
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