Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard was proposed by China National Light Industry Council.
This standard is under the jurisdiction of SAC/TC 480 National Technical Committee on Furniture of Standardization Administration of China.
The assessment method of the heavy metal Sb, As, Ba, Se and Cr (VI) in furniture
Warning: the personnel using this standard shall have practical work experience in laboratory. This standard does not purport to address all of the safety problems. The users are under the obligation to adopt proper safety and health measures and shall ensure conformance with the requirements specified in relevant national regulations.
1 Scope
This standard specifies the test and assessment methods of the soluble heavy metal Sb, As, Ba, Se and Cr (VI) in furniture.
This standard is applicable to furniture products whose surface is covered with coating, veneer layer and soft covering.
This standard is not applicable to furniture products whose surfaces covered with porcelain glaze of ceramic or enamels of metal, all those that are fused or melted into glass, enamel or porcelain glaze of ceramic, or those with metal electroplated coatings.
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 602-2002 Chemical reagent - Preparations of standard solutions for impurity
GB/T 6682 Water for analytical laboratory use - Specification and test methods
3 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
3.1
base material
the material that carries the coating or veneer layer in the furniture
3.2
coating
the material coated to the base material surface of furniture
Example: paint, varnish, gloss varnish, varnish stain, powder coating, printing ink, oils, wax, putty and inorganic coating.
3.3
veneer layer
a layer of thin material overlaying the base material surface of the furniture for protection and decoration
Example: soft veneer materials (such as PVC, decorative paper, plastic film, leather, artificial leather, fabrics, etc.) and hard veneer materials (wood decorative veneer, natural veneer, artificial veneer, plastic laminated board, sheet metal, tubes and impregnated thermosetting resins paper, etc.).
3.4
soft covering
a thin layer of soft material, which is coated on the surface of the furniture base materials or core materials for protection and decoration, such as leather, textile fabric, etc
3.5
scraping
the process of obtaining a coating or a veneer layer from base materials with mechanical methods
4 Theory
4.1 Assessment basis
According to the reaction theory of heavy metal and acid and alkali, in the case of daily use, the content of the soluble heavy metals absorbed by human bodies shall be simulated after the soluble heavy metals in the furniture surface coating is dissolved by the user's acid and alkaline sweat or the saliva generated by suck and bite of children.
4.2 Soluble heavy metals Sb, As, Ba, Se
With the prepared sample treated with 0.07 mol/L hydrochloric acid solution or acidic sweat, after the treatment of furniture materials, the content of soluble heavy metals Sb, As, Ba, Se in the specimen solution shall be determined by the appropriate analytical instrument (such as atomic absorption spectrometer and atomic fluorescence spectrometer or inductively coupled plasma-optical emission spectrometer).
4.3 Cr(VI)
The prepared sample shall be treated with 0.07 mol/L hydrochloric acid solution or acidic sweat or alkaline sweat, and the Cr (VI) in the treatment solution reacts with diphenylcarbazide in an acidic solution to form a purple-red complex. Then the content of Cr(VI) in the specimen solution shall be determined at a 540nm wavelength position by spectrophotometric method or with C18 reversed-phase chromatographic column and methanol + phosphoric acid aqueous solution = 30+70 liquid chromatography.
The extraction conditions have a direct influence on the test results of this method. The results obtained by different extraction conditions (extractant, pH, extraction time) are not comparable with those obtained by this method.
5 Instruments and apparatus
5.1 Soluble heavy metals Sb, As, Ba, Se in furniture
5.1.1 Instruments and apparatus in general laboratories.
5.1.2 Analytical instruments with proper limit of detection, such as atomic absorption spectrometer and atomic fluorescence spectrometer or inductively coupled plasma-optical emission spectrometer.
5.1.3 Balance: with precision of 0.1mg.
5.1.4 Grinding equipment: such as grinder, scissor and scraper.
5.1.5 Stainless steel metal screen: with pore diameter of 0.5 mm (32 mesh).
5.1.6 Water bath shaker: with temperature control function and adjustable frequency.
5.1.7 Acidometer: with precision in 0.1 pH.
5.1.8 Filter membrane (applicable to water solution): with pore diameter of 0.45μm.
5.1.9 Pipette: 1 mL, 2 mL, 5 mL, 10 mL, 25 mL, 50 mL, etc.
5.1.10 Volumetric flask: 25 mL, 50 mL, 100 mL, 1,000 mL, etc.
5.1.11 Beaker: 500 mL, 1,000 mL, etc.
5.1.12 Extractor: 150 mL and 750 mL conical flask with cover or 150 mL and 250 mL beaker with a watch glass.
5.1.13 All the glass ware, sample containers, prior to use, shall be soaked with nitric acid solution for 24h and then cleaned with water and dried.
5.2 Cr(VI) in furniture
5.2.1 Instruments and apparatus in general laboratories.
5.2.2 Spectrophotometer.
5.2.3 Grinding equipment: such as grinder, scissor and scraper.
5.2.4 Stainless steel metal screen: with pore diameter of 0.5 mm (32 mesh).
5.2.5 Water bath shaker: with temperature control function and adjustable frequency.
5.2.6 Acidometer: with precision in 0.1 pH.
5.2.7 Balance: with precision of 0.1mg.
5.2.8 Beaker: 500 mL, etc.
5.2.9 Pipette: 1 mL, 2 mL, 5 mL, 10 mL, 25 mL, etc.
5.2.10 Volumetric flask: 25 mL, 50 mL, 100 mL, 1,000 mL, etc.
5.2.11 Extractor: 150 mL and 250 mL conical flask with cover or 150 mL and 250 mL beaker with a watch glass.
5.2.12 Filter membrane (applicable to water solution): with pore diameter of 0.45μm.
5.2.13 Measuring cylinder: 10 mL, 50 mL, 100 mL, etc.
5.2.14 High performance liquid chromatograph: equipped with constant flow pump, column oven, variable wavelength ultraviolet detector.
5.2.15 Chromatographic data processor or chromatographic working station.
5.2.16 Chromatographic column: Agilent Zorbax Eclipse XDB-C18 25 cm × 4.6 mm (inner diameter), 5 μm stainless steel column; or chromatographic column with equivalent effect.
5.2.17 Filter: with pore diameter of filter membrane of about 0.45μm.
5.2.18 All the glass ware, sample containers, prior to use, shall be soaked with nitric acid solution for 24h and then cleaned with water and dried.
6 Reagents and solutions
6.1 Reagents and water
Analytical reagents or above shall be used in analytical tests. The water used shall meet the requirements of Grade II water or above, or fresh redistilled water or ultrapure water specified in GB/T 6682.
6.2 Soluble heavy metals Sb, As, Ba, Se in furniture
6.2.1 Simulation of gastric acid extraction
6.2.1.1 Hydrochloric acid: with density of approximately 1.18 g/mL.
6.2.1.2 Hydrochloric acid solution 1: 0.07 mol/L.
6.2.1.3 Hydrochloric acid solution 2: approximately 2 mol/L.
6.2.1.4 Nitric acid: with the density of approximately 1.40 g/mL.
6.2.1.5 Nitric acid solution: 1+1 (volume ratio).
6.2.1.6 Standard stock solution of Sb, As, Ba, Se (purchased or prepared according to GB/T 602-2002): with concentration of 100 mg/L or of 1,000 mg/L.
Note: this method should be used for the detection of special furniture for infants and children.
6.2.2 Simulation of acidic sweat extraction
6.2.2.1 L-histidine hydrochloride monohydrate(C6H9O2N3HCI·H2O).
6.2.2.2 Disodium hydrogen phosphate dihydrate (NaH2PO4·2H2O).
6.2.2.3 Sodium chloride (NaCl).
6.2.2.4 Sodium hydroxide: 0.1 mol/L.
6.2.2.5 Alkaline sweat: weigh 0.5 g of L-histidine hydrochloride monohydrate, 5.0 g of sodium chloride, 2.2 g of disodium hydrogen phosphate dihydrate in a 500 mL beaker, dilute with distilled water and fill to 1 L. Adjust the pH to 5.5 with 0.1 mol/L sodium hydroxide solution. The reagent shall be prepared immediately before use.
6.2.2.6 In accordance with those specified in 6.2.1.6.
6.3 Cr (VI) in furniture
6.3.1 Simulation of gastric acid extraction
6.3.1.1 Diphenylcarbazide.
6.3.1.2 Acetone.
6.3.1.3 Methanol.
6.3.1.4 Phosphoric acid solution 1+1 (Volume ratio).
6.3.1.5 Diphenylcarbazide chromogenic agent: weight 1.0 g of diphenylcarbazide (see 6.3.1.1) and dissolve it into 100mL acetone (see 6.3.1.2), then keep it into a brown bottle. The solution shall be stored at 4 ℃ with a validity period of two weeks. If the color of solution fades, it shall be re-prepared.
6.3.1.6 Cr(VI) standard stock solution (purchased or prepared according to method II of GB/T 602-2002): with concentration of 100 mg/L.
6.3.1.7 Cr(VI) standard solution: with concentration of 5mg/L. Shift 5mL Cr(VI) standard stock solution (see 6.3.1.6) with pipette into a 100mL volumetric flask, dilute to the scale with water. This solution shall be prepared on the day when use it. This solution shall be prepared on the day prior to use.
6.3.1.8 In accordance with those specified in 6.2.1.1 ~ 6.2.1.5. The method should be used for the detection of special furniture for infants and children.
6.3.2 Simulation of acidic sweat extraction
6.3.2.1 In accordance with those specified in 6.3.1.3.
6.3.2.2 In accordance with those specified in 6.3.1.4.
6.3.2.3 In accordance with those specified in 6.3.1.6.
6.3.2.4 In accordance with those specified in 6.3.1.7.
6.3.2.5 In accordance with those specified in 6.2.2.1 ~ 6.2.2.5.
6.3.3 Simulation of alkaline sweat extraction
6.3.3.1 Disodium hydrogen phosphate dodecahydrate (Na2HPO4·12H2O).
6.3.3.2 Disodium hydrogen phosphate dihydrate (Na2HPO4·2H2O).
6.3.3.3 Alkaline sweat: weigh 0.5 g of L-histidine hydrochloride monohydrate, 5.0 g of sodium chloride, 5.0 g of disodium hydrogen phosphate dodecahydrate or 2.5 g of disodium hydrogen phosphate dihydrate in a 500 mL beaker, dilute with distilled water and fill to 1 L. Adjust the pH to 8.0 with 0.1 mol/L sodium hydroxide solution. The reagent shall be prepared immediately before use.
6.3.3.4 In accordance with those specified in 6.2.2.1.
6.3.3.5 In accordance with those specified in 6.2.2.3~6.2.2.4.
6.3.3.6 In accordance with those specified in 6.3.1.7.
7 Preparation and treatment of specimens
7.1 Preparation of samples
7.1.1 Preparation of coatings and specimens with hard veneer materials
Scrape the specimen coating with a spatula or other tools at room temperature, which can be done after dripping a proper amount of solvent on the surface of the coating for softening. Then the specimen scraped after softening shall be collected in the fume hood after the solvent volatilizes; the hard veneer material can be obtained by suitable equipment. The collected specimen shall be ground at normal temperature. Take the powder passing through a test sieve (0.5 mm) as a measurement specimen. The coatings that can't be ground or other hard materials may be cut up with a clean scissor as much as possible and sample treatment may be carried out directly without screening.
7.1.2 Preparation of soft veneer layer specimens and soft covering leathers and textile fabric specimens
The soft veneer layer or the soft covering of the specimen shall be extracted with an appropriate tool at a normal temperature, and cut to 5 mm × 5 mm or less with scissors or other appropriate tools, and then take an appropriate amount of those as a measurement specimen. If the specimens are of different materials, then they are sampled separately for testing. The specimen taken shall be representative.
7.1.3 Sampling positions
The positions that the human body can touch when the furniture is in normal use.
7.2 Treatment of samples
7.2.1 Treatment of measured samples with soluble heavy metals Sb, As, Ba, Se in furniture
7.2.1.1 Method I: simulating gastric acid treatment
Take 0.5 g (accurate to 0.1 mg) of the prepared specimen and 25 mL of 0.07 mol/L hydrochloric acid solution (see 6.2.1.2) and put them into an appropriate container, then mix them well at (37 ± 2) ℃. Shake it for 1min and inspect the acidity of the mixed solution. If the pH is larger than 1.2, then add about 2 mol/L hydrochloric acid solution (see 6.2.1.3)drop by drop into it during shaking the mixture solution till the pH reaching 1.2. Ensure that the mixed solution is protected from light. Then put the mixed solution in a temperature controlled water bath shaker (with an oscillation frequency between 100 r/min and 200 r/min) for 1 h’ s continuous shaking at the temperature of (37 ± 2) ° C. After that, allow the mixed solution to stand for 1 h at the same temperature. If necessary, separate it with a centrifugal machine (with a centrifuge capacity of 5,000 g). Then the filtration separation treatment shall be carried out as quickly as possible after the standing time. If the centrifuging treatment is used, the time shall not exceed 10 min. Prior to the elemental analysis, where the specimen solution is stored for more than 1 d, it is necessary to add the hydrochloric acid solution to stabilize it so that the concentration of the stored specimen solution c (HCl) is about 1 mol/L.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Theory
5 Instruments and apparatus
6 Reagents and solutions
7 Preparation and treatment of specimens
8 Test procedure
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard was proposed by China National Light Industry Council.
This standard is under the jurisdiction of SAC/TC 480 National Technical Committee on Furniture of Standardization Administration of China.
The assessment method of the heavy metal Sb, As, Ba, Se and Cr (VI) in furniture
Warning: the personnel using this standard shall have practical work experience in laboratory. This standard does not purport to address all of the safety problems. The users are under the obligation to adopt proper safety and health measures and shall ensure conformance with the requirements specified in relevant national regulations.
1 Scope
This standard specifies the test and assessment methods of the soluble heavy metal Sb, As, Ba, Se and Cr (VI) in furniture.
This standard is applicable to furniture products whose surface is covered with coating, veneer layer and soft covering.
This standard is not applicable to furniture products whose surfaces covered with porcelain glaze of ceramic or enamels of metal, all those that are fused or melted into glass, enamel or porcelain glaze of ceramic, or those with metal electroplated coatings.
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 602-2002 Chemical reagent - Preparations of standard solutions for impurity
GB/T 6682 Water for analytical laboratory use - Specification and test methods
3 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
3.1
base material
the material that carries the coating or veneer layer in the furniture
3.2
coating
the material coated to the base material surface of furniture
Example: paint, varnish, gloss varnish, varnish stain, powder coating, printing ink, oils, wax, putty and inorganic coating.
3.3
veneer layer
a layer of thin material overlaying the base material surface of the furniture for protection and decoration
Example: soft veneer materials (such as PVC, decorative paper, plastic film, leather, artificial leather, fabrics, etc.) and hard veneer materials (wood decorative veneer, natural veneer, artificial veneer, plastic laminated board, sheet metal, tubes and impregnated thermosetting resins paper, etc.).
3.4
soft covering
a thin layer of soft material, which is coated on the surface of the furniture base materials or core materials for protection and decoration, such as leather, textile fabric, etc
3.5
scraping
the process of obtaining a coating or a veneer layer from base materials with mechanical methods
4 Theory
4.1 Assessment basis
According to the reaction theory of heavy metal and acid and alkali, in the case of daily use, the content of the soluble heavy metals absorbed by human bodies shall be simulated after the soluble heavy metals in the furniture surface coating is dissolved by the user's acid and alkaline sweat or the saliva generated by suck and bite of children.
4.2 Soluble heavy metals Sb, As, Ba, Se
With the prepared sample treated with 0.07 mol/L hydrochloric acid solution or acidic sweat, after the treatment of furniture materials, the content of soluble heavy metals Sb, As, Ba, Se in the specimen solution shall be determined by the appropriate analytical instrument (such as atomic absorption spectrometer and atomic fluorescence spectrometer or inductively coupled plasma-optical emission spectrometer).
4.3 Cr(VI)
The prepared sample shall be treated with 0.07 mol/L hydrochloric acid solution or acidic sweat or alkaline sweat, and the Cr (VI) in the treatment solution reacts with diphenylcarbazide in an acidic solution to form a purple-red complex. Then the content of Cr(VI) in the specimen solution shall be determined at a 540nm wavelength position by spectrophotometric method or with C18 reversed-phase chromatographic column and methanol + phosphoric acid aqueous solution = 30+70 liquid chromatography.
The extraction conditions have a direct influence on the test results of this method. The results obtained by different extraction conditions (extractant, pH, extraction time) are not comparable with those obtained by this method.
5 Instruments and apparatus
5.1 Soluble heavy metals Sb, As, Ba, Se in furniture
5.1.1 Instruments and apparatus in general laboratories.
5.1.2 Analytical instruments with proper limit of detection, such as atomic absorption spectrometer and atomic fluorescence spectrometer or inductively coupled plasma-optical emission spectrometer.
5.1.3 Balance: with precision of 0.1mg.
5.1.4 Grinding equipment: such as grinder, scissor and scraper.
5.1.5 Stainless steel metal screen: with pore diameter of 0.5 mm (32 mesh).
5.1.6 Water bath shaker: with temperature control function and adjustable frequency.
5.1.7 Acidometer: with precision in 0.1 pH.
5.1.8 Filter membrane (applicable to water solution): with pore diameter of 0.45μm.
5.1.9 Pipette: 1 mL, 2 mL, 5 mL, 10 mL, 25 mL, 50 mL, etc.
5.1.10 Volumetric flask: 25 mL, 50 mL, 100 mL, 1,000 mL, etc.
5.1.11 Beaker: 500 mL, 1,000 mL, etc.
5.1.12 Extractor: 150 mL and 750 mL conical flask with cover or 150 mL and 250 mL beaker with a watch glass.
5.1.13 All the glass ware, sample containers, prior to use, shall be soaked with nitric acid solution for 24h and then cleaned with water and dried.
5.2 Cr(VI) in furniture
5.2.1 Instruments and apparatus in general laboratories.
5.2.2 Spectrophotometer.
5.2.3 Grinding equipment: such as grinder, scissor and scraper.
5.2.4 Stainless steel metal screen: with pore diameter of 0.5 mm (32 mesh).
5.2.5 Water bath shaker: with temperature control function and adjustable frequency.
5.2.6 Acidometer: with precision in 0.1 pH.
5.2.7 Balance: with precision of 0.1mg.
5.2.8 Beaker: 500 mL, etc.
5.2.9 Pipette: 1 mL, 2 mL, 5 mL, 10 mL, 25 mL, etc.
5.2.10 Volumetric flask: 25 mL, 50 mL, 100 mL, 1,000 mL, etc.
5.2.11 Extractor: 150 mL and 250 mL conical flask with cover or 150 mL and 250 mL beaker with a watch glass.
5.2.12 Filter membrane (applicable to water solution): with pore diameter of 0.45μm.
5.2.13 Measuring cylinder: 10 mL, 50 mL, 100 mL, etc.
5.2.14 High performance liquid chromatograph: equipped with constant flow pump, column oven, variable wavelength ultraviolet detector.
5.2.15 Chromatographic data processor or chromatographic working station.
5.2.16 Chromatographic column: Agilent Zorbax Eclipse XDB-C18 25 cm × 4.6 mm (inner diameter), 5 μm stainless steel column; or chromatographic column with equivalent effect.
5.2.17 Filter: with pore diameter of filter membrane of about 0.45μm.
5.2.18 All the glass ware, sample containers, prior to use, shall be soaked with nitric acid solution for 24h and then cleaned with water and dried.
6 Reagents and solutions
6.1 Reagents and water
Analytical reagents or above shall be used in analytical tests. The water used shall meet the requirements of Grade II water or above, or fresh redistilled water or ultrapure water specified in GB/T 6682.
6.2 Soluble heavy metals Sb, As, Ba, Se in furniture
6.2.1 Simulation of gastric acid extraction
6.2.1.1 Hydrochloric acid: with density of approximately 1.18 g/mL.
6.2.1.2 Hydrochloric acid solution 1: 0.07 mol/L.
6.2.1.3 Hydrochloric acid solution 2: approximately 2 mol/L.
6.2.1.4 Nitric acid: with the density of approximately 1.40 g/mL.
6.2.1.5 Nitric acid solution: 1+1 (volume ratio).
6.2.1.6 Standard stock solution of Sb, As, Ba, Se (purchased or prepared according to GB/T 602-2002): with concentration of 100 mg/L or of 1,000 mg/L.
Note: this method should be used for the detection of special furniture for infants and children.
6.2.2 Simulation of acidic sweat extraction
6.2.2.1 L-histidine hydrochloride monohydrate(C6H9O2N3HCI·H2O).
6.2.2.2 Disodium hydrogen phosphate dihydrate (NaH2PO4·2H2O).
6.2.2.3 Sodium chloride (NaCl).
6.2.2.4 Sodium hydroxide: 0.1 mol/L.
6.2.2.5 Alkaline sweat: weigh 0.5 g of L-histidine hydrochloride monohydrate, 5.0 g of sodium chloride, 2.2 g of disodium hydrogen phosphate dihydrate in a 500 mL beaker, dilute with distilled water and fill to 1 L. Adjust the pH to 5.5 with 0.1 mol/L sodium hydroxide solution. The reagent shall be prepared immediately before use.
6.2.2.6 In accordance with those specified in 6.2.1.6.
6.3 Cr (VI) in furniture
6.3.1 Simulation of gastric acid extraction
6.3.1.1 Diphenylcarbazide.
6.3.1.2 Acetone.
6.3.1.3 Methanol.
6.3.1.4 Phosphoric acid solution 1+1 (Volume ratio).
6.3.1.5 Diphenylcarbazide chromogenic agent: weight 1.0 g of diphenylcarbazide (see 6.3.1.1) and dissolve it into 100mL acetone (see 6.3.1.2), then keep it into a brown bottle. The solution shall be stored at 4 ℃ with a validity period of two weeks. If the color of solution fades, it shall be re-prepared.
6.3.1.6 Cr(VI) standard stock solution (purchased or prepared according to method II of GB/T 602-2002): with concentration of 100 mg/L.
6.3.1.7 Cr(VI) standard solution: with concentration of 5mg/L. Shift 5mL Cr(VI) standard stock solution (see 6.3.1.6) with pipette into a 100mL volumetric flask, dilute to the scale with water. This solution shall be prepared on the day when use it. This solution shall be prepared on the day prior to use.
6.3.1.8 In accordance with those specified in 6.2.1.1 ~ 6.2.1.5. The method should be used for the detection of special furniture for infants and children.
6.3.2 Simulation of acidic sweat extraction
6.3.2.1 In accordance with those specified in 6.3.1.3.
6.3.2.2 In accordance with those specified in 6.3.1.4.
6.3.2.3 In accordance with those specified in 6.3.1.6.
6.3.2.4 In accordance with those specified in 6.3.1.7.
6.3.2.5 In accordance with those specified in 6.2.2.1 ~ 6.2.2.5.
6.3.3 Simulation of alkaline sweat extraction
6.3.3.1 Disodium hydrogen phosphate dodecahydrate (Na2HPO4·12H2O).
6.3.3.2 Disodium hydrogen phosphate dihydrate (Na2HPO4·2H2O).
6.3.3.3 Alkaline sweat: weigh 0.5 g of L-histidine hydrochloride monohydrate, 5.0 g of sodium chloride, 5.0 g of disodium hydrogen phosphate dodecahydrate or 2.5 g of disodium hydrogen phosphate dihydrate in a 500 mL beaker, dilute with distilled water and fill to 1 L. Adjust the pH to 8.0 with 0.1 mol/L sodium hydroxide solution. The reagent shall be prepared immediately before use.
6.3.3.4 In accordance with those specified in 6.2.2.1.
6.3.3.5 In accordance with those specified in 6.2.2.3~6.2.2.4.
6.3.3.6 In accordance with those specified in 6.3.1.7.
7 Preparation and treatment of specimens
7.1 Preparation of samples
7.1.1 Preparation of coatings and specimens with hard veneer materials
Scrape the specimen coating with a spatula or other tools at room temperature, which can be done after dripping a proper amount of solvent on the surface of the coating for softening. Then the specimen scraped after softening shall be collected in the fume hood after the solvent volatilizes; the hard veneer material can be obtained by suitable equipment. The collected specimen shall be ground at normal temperature. Take the powder passing through a test sieve (0.5 mm) as a measurement specimen. The coatings that can't be ground or other hard materials may be cut up with a clean scissor as much as possible and sample treatment may be carried out directly without screening.
7.1.2 Preparation of soft veneer layer specimens and soft covering leathers and textile fabric specimens
The soft veneer layer or the soft covering of the specimen shall be extracted with an appropriate tool at a normal temperature, and cut to 5 mm × 5 mm or less with scissors or other appropriate tools, and then take an appropriate amount of those as a measurement specimen. If the specimens are of different materials, then they are sampled separately for testing. The specimen taken shall be representative.
7.1.3 Sampling positions
The positions that the human body can touch when the furniture is in normal use.
7.2 Treatment of samples
7.2.1 Treatment of measured samples with soluble heavy metals Sb, As, Ba, Se in furniture
7.2.1.1 Method I: simulating gastric acid treatment
Take 0.5 g (accurate to 0.1 mg) of the prepared specimen and 25 mL of 0.07 mol/L hydrochloric acid solution (see 6.2.1.2) and put them into an appropriate container, then mix them well at (37 ± 2) ℃. Shake it for 1min and inspect the acidity of the mixed solution. If the pH is larger than 1.2, then add about 2 mol/L hydrochloric acid solution (see 6.2.1.3)drop by drop into it during shaking the mixture solution till the pH reaching 1.2. Ensure that the mixed solution is protected from light. Then put the mixed solution in a temperature controlled water bath shaker (with an oscillation frequency between 100 r/min and 200 r/min) for 1 h’ s continuous shaking at the temperature of (37 ± 2) ° C. After that, allow the mixed solution to stand for 1 h at the same temperature. If necessary, separate it with a centrifugal machine (with a centrifuge capacity of 5,000 g). Then the filtration separation treatment shall be carried out as quickly as possible after the standing time. If the centrifuging treatment is used, the time shall not exceed 10 min. Prior to the elemental analysis, where the specimen solution is stored for more than 1 d, it is necessary to add the hydrochloric acid solution to stabilize it so that the concentration of the stored specimen solution c (HCl) is about 1 mol/L.
Contents of GB/T 36021-2018
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Theory
5 Instruments and apparatus
6 Reagents and solutions
7 Preparation and treatment of specimens
8 Test procedure
