NATIONAL STANDARD OF THE PEOPLE'S REPUBLIC OF CHINA. Limit of Harmful Substances of Automobile Coatings 汽车涂料中有害物质限量

Transcription

1 ICS G 51 GB NATIONAL STANDARD OF THE PEOPLE'S REPUBLIC OF CHINA GB Limit of Harmful Substances of Automobile Coatings 汽车涂料中有害物质限量 GB How to BUY & immediately GET a full-copy of this standard? Search --> Add to Cart --> Checkout (3-steps); 3. No action is required - Full-copy of this standard will be automatically & immediately delivered to your address in 0~60 minutes. 4. Support: Sales@ChineseStandard.net. Wayne, Sales manager Issued on: September 3, 2009 Implemented on: June 1, 2010 Jointly issued by: General Administration of Quality Supervision, Inspection and Quarantine of the People s Republic of China; Standardization Administration of the People s Republic of China.

2 Contents Foreword... II 1 Scope Normative reference documents Terms and Definitions Product category Requirement Test method Test rule Packing mark... 5 Annex A (Normative) Test of volatile organic compounds (VOC) content... 6 Annex B (Normative) Tests of benzene, toluene, ethylbenzene, xylene, glycol ether and ether ester in solvent based coating Gas chromatography method Annex C (Normative) Content test of glycol ether and ether ester in water paint Gas chromatography method Annex D (Normative) Content test of led, cadmium, mercury Annex E (Normative) Content test of sexavalent chrome... 23

3 Foreword All the technical contents in this standard are compulsory. Annex A, Annex B, Annex C, Annex D, Annex E in this standard are normative annexes. This standard is presented by the China Petroleum and Chemical Industry Association. This standard is under the centralized management of National Technical Committee of Paints & Pigments for Standardization. The main drafting organizations of this code: CNOOC Changzhou Paint & Coatings Industry Research Institute, Chery Automobile Co., Ltd., FAW Research & Development Center, BASF Coatings International Trade (Shanghai),AkzoNobel Sikkens Car Refinishes (Suzhou) Co., Ltd., Hunan Kansai Automotive Coating Co.,Ltd, Jiangsu Hongye Coatings Co.,Ltd, Hangzhou Unires Chemical Co.,Ltd, Shenzhen Pinefield Chemical Enterprises Co.,Ltd, Fujian Xin Zhan Wang Group Co., Ltd., Changzhou Planet Coatings Co.,Ltd, Jiangsu Baihe Coatings Co.,Ltd, Jiangsu Haoyue Coatings Co.,Ltd, Shenzhen Centre Testing International Corporation. The chief drafing staff of this code: Tang Ying, Chen Yuezhen, Li Daming, Zhang Guozhong, Song Hua, Li Feng, Fu Qing, Yang Pengfei, Yu Xinli, Wang Songxian, Zhang Dingde, Zhan Jianxin, Xue Fang, Bao Boqing, Jiang Chun, Guo Yong. II

4 Limit of Harmful Substances of Automobile Coatings 1 Scope This standard specifies the requirements, test method, test rules and packing mark of harmful-substance permissible limit in original coating, repair coating and spare coating used on passenger car, commercial car, trailer, road train for human and environment. This standard is applicable to all kinds of automobile coatings except putty and coating with special function. Note: in this standard the coatings with specific function are referred to the polypropylene-ground adhesion accelerant (PP water), the anti (resistant)-stone-bumping coating [except the auxiliary anti (resistant)-stone-bumping coating], the auxiliary material (joint water) to remove marks on the joint of new and old films, etc. 2 Normative reference documents The terms of the following documents in the passage of this standard become the terms of this standard. Note the date of any reference document, and its subsequent amendments all alone (not including the contents of errata) or revised edition are not applicable to this standard, however, under this standard to encourage the parties to reach an agreement to explore the possibility of using the latest version of these documents. Note the dates are not cited documents; the latest version applies to this standard. GB/T1250 Rules for expression and judgment of limiting values GB/T Paints varnishes and plastics Determination of non-volatile-matter content (ISO 3251: 2003, IDT) GB/T3186 Paints varnishes and raw materials for paints and varnishes-sampling (GB/T , ISO15528: 2000, IDT) GB/T Water for laboratory use; Specifications (ISO3696: 1987, MOD) GB/T Paints and varnishes Determination of density Pyknometer method (ISO : 1997, Paints and varnishes Determination of density Part1: Pyknometer method, IDT) GB/T9750 Marks for package of coating products 3 Terms and Definitions The following terms and definitions are applicable to this standard. 3.1 Solid color paints Paints of pearly-lustre-lamp effect pigment without metal. 3.2 Base coats Paints which the surface needs coating varnish. 3.3 Solid color paints without clearcoat Solid color paints which the surface needs coating varnish

5 Annex A (Normative) Test of volatile organic compounds (VOC) content A.1 Principle If the organic compounds with boiling point of above 250are not detected in the sample after the gas chromatography test, the tested volatile content is the VOC content of product. If the organic compounds with boiling point of above 250 are detected, the qualitative identification and quantitative analysis shall be carried out on the organic compounds with boiling point of above 250 in the sample. The volatile content deducting the content of organic compound with boiling point of above 250 is the V OC content of product. A.2 Material and reagent A.2.1 Carrier gas: nitrogen, purity %. A.2.2 Fuel gas: hydrogen, purity %. A.2.3 Combustion-supporting gas: air. A.2.4 Auxiliary gas (septum purging and tail and make-up gas): nitrogen with the same property with carrier gas. A.2.5 Internal standard: compounds which don't exist in the sample and can be separated completely from the other compositions in the chromatogram. The purity is at least 99% (mass fraction) or the known purity. For example: dimethyl phthalate, diethyl phthalate, etc. A.2.6 Calibrating compound: compounds used for calibration, the purity is at least 99% (mass fraction) or the known purity. A.2.7 Diluting solvent: organic solvents used for diluting sample without any substance of disturbing test. The purity is at least 99% (mass fraction) or the known purity. For example: ethyl acetate, etc. A.2.8 Marker: compounds used to distinguish VOC component from non-voc component according to VOC definition. In this standard the marker is specified to be diethylene adipate (boiling point is 251 ). A.3 Instrument and equipment A.3.1 Gas chromatograph is equipped with the following equipments: A3.1.1 The injection port of divisor and the removable inner lining of vaporizing chamber. A Programmed heating controller. A Detector Any of the following three kinds of detectors can be used: A Flame ionization detector (FID). A The calibrated and tuned velocitron or other mass selective detector. A The calibrated Fourier transform infrared spectrometry (FT-IR spectrograph). Note: if the detectors in A or A are adopted to process a qualitative identification to the organic compounds with boiling point of above 250, the apparatus shall connect with the gas chromatograph and shall be operated according to the relevant illustrations of the apparatus manufacturer. A Chromatographic column: it shall be able to enough separate the measured objects, 6

6 shall be used for every time to optimize the apparatus in order to make their sensitivity, stability and separating effect in the best state. The sample size and the split ratio shall be assorted to avoid beyond the chromatographic-column capacity and shall be within the linear range of apparatus detector. A Qualitative analysis The marker (A.2.8) shall be put into the chromatograph to measure its holding time on the dimethyl polysiloxane capillary column in order to determine the integral origination in the chromatogram according to VOC definition presented in 3.4. The mixed sample shall be prepared according to the construction mixture ratio shown on product; after the even mixture, the 2g sample shall be weighed and diluted with the appropriate amount of diluents (A.2.7); the 1.0μL mixed sample is taken by sample injector (A.3.2) and put into the chromatograph; the compounds which the holding time is above marker shall be performed the qualitative identification with the chromatogram record. The combinations of gas chromatograph and mass selective detector (A ) or FT-IR spectrograph (A ) are preferred, and the test conditions of gas chromatography in A.4 are used. mixture. Note: as for the bi-component cross-linking type coatings, the components shall be analyzed as soon as possible after the A Calibration A If the compounds used in calibration can be bought, the following methods shall be used to measure the relative correction factor. A The preparation of calibration sample: a certain amount (accurate to 0.1mg) of all kinds of calibration compounds (A.2.6) identified by A shall be respectively weighed and put into the sample preparation bottle (A.3.3); the taken quality and the respective content in the sample to be tested shall be in the same order of magnitude. Then the internal standard (A.2.5) of close quality with compound to be tested shall be taken and put into the same sample preparation bottle; the mixture shall be diluted with diluting solvent (A.2.7). The sample preparation bottle shall be sealed and shaken up. A Test of relative correction factor: the instrument parameter shall be optimized according to A specifications under the same test condition of gas chromatography with the test sample. The appropriate amount of calibration mixture shall be put into the gas chromatograph; the chromatogram shall be recorded and the relative correction factor of each kind of compound shall be respectively calculated according to the Formula (A.2): R m A ei is i = (A.2) mis Aei Where: R i Relative correction factor of compound i; m ei The quality of compound i in the calibration mixture, the unit is gram (g); m is The quality of internal standard in the calibration mixture, the unit is gram (g); A is Peak area of internal standard; A ei Peak area of compound i. The measurement result shall keep three effective figures. A In case that the chromatogram peak can not be determined the nature or the 8

7 Annex B (Normative) Tests of benzene, toluene, ethylbenzene, xylene, glycol ether and ether ester in solvent based coating Gas chromatography method B.1 Principle The sample shall be directly injected into the gas chromatograph after dilution and detected by hydrogen flame ionization detector after separated by chromatographic column; the sample shall be quantified by internal standard method. B.2 Material and reagent B.2.1 Carrier gas: nitrogen, purity %. B.2.2 Fuel gas: hydrogen, purity %. B.2.3 Combustion-supporting gas: air. B.2.4 Auxiliary gas (septum purging and tail and make-up gas): nitrogen with the same property with carrier gas. B.2.5 Internal standard: compounds which don't exist in the sample and can be separated completely from the other compositions in the chromatogram. The purity is at least 99% (mass fraction) or the known purity. For example: normal heptane, pentane, etc. B.2.6 Standard compound: benzene, toluene, ethylbenzene, xylene, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, cellosolve, cellosolve acetate and diethylene glycol butylether acetate; the purity is at least 99% (mass fraction) or the known purity. B.2.7 Diluting solvent: organic solvents used for diluting sample without any substance of disturbing test. The purity is at least 99% (mass fraction) or the known purity. For example: ethyl acetate, normal hexane, etc. B.3 Instrument and equipment B.3.1 Gas chromatograph is equipped with the following equipments: B The injection port of divisor and the removable inner lining of vaporizing chamber. B Programmed heating controller. B Detector: flame ionization detector (FID). B Chromatographic column: it shall be able to enough separate the measured objects, such as the polydimethyl siloxane capillary column, 6% cyanopropylphenyl/94% dimethyl polysiloxane capillary column, polyethylene glycol capillary column or corresponding models. B.3.2 Sample injector: the capacity shall be at least two times of the sample size. B.3.3 Sample preparation bottle: the glass bottle of about 10mL with the sealed bottle cap. B.3.4 Scale: the accuracy is 0.1mg. B.4 Test condition of gas chromatography Chromatographic column: dimethyl polysiloxane capillary column, 30m 0.25mm 0.25μm; Temperature of injection port: 240 ; 11

8 m R = A ei im i (B.1) mim Aci Where: R i Relative correction factor of tested compound i; m ei The quality of compound i in the calibration mixture, the unit is gram (g); m im The quality of internal standard in the calibration mixture, the unit is gram (g); A is Peak area of internal standard; A ei Peak area of compound i. B.5.4 Sample test B Sample preparation: the mixed sample shall be prepared according to the construction mixture ratio shown on the product and taken 2g (accurate to 0.1mg) after the even mixture; the internal standard (B.2.5) of the same magnitude order with the tested object shall be taken into the sample preparation bottle (B.3.3); the proper amount of diluting solvent (B.2.7) shall be added into the same sample preparation bottle to dilute the sample, and then the sample preparation bottle shall be sealed and shaken up. mixture. Note: as for the bi-component cross-linking type coatings, the components shall be analyzed as soon as possible after the B The instrument parameters shall be set according to the optimality conditions in the calibration. B The 1.0μL sample prepared according to B shall be injected into the gas chromatograph and the chromatogram shall be recorded. Then the contents of tested compounds (benzene, toluene, ethylbenzene, xylene, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, cellosolve, cellosolve acetate and diethylene glycol butylether acetate) in the sample shall be calculated according to Formula (B.2) respectively. mis Ai Ri w i = 100 (B.2) m A s is Where: ωi Mass fraction of tested compounds in the sample, %; Ri Relative correction factor of tested compound i; m The quality of internal standard in the sample, the unit is gram (g); m Quality in the sample, the unit is gram (g); Ai Peak area of tested compound i; A Peak area of internal standard. Note: if the chromatogram test condition in B.4 cannot separate effectively the tested objects so that the quantity can not be determined accurately, other chromatographic columns (see B.3.1.4) or better chromatogram test conditions can be used, the quantitative determination shall be conducted after the effective segregation of tested objects. B.6 Calculation B.6.1 Calculation of sum of toluene, ethylbenzene and xylene The respective mass fraction ωi of toluene, ethylbenzene and xylene shall be calculated according to the Formula (B.2), then the sum of toluene, ethylbenzene and xylene in the product shall be calculated according to the Formula (B.3): 13

9 C.3.2 Fuel gas: hydrogen, purity %. C.3.3 Combustion-supporting gas: air. C.3.4 Auxiliary gas (septum purging and tail and make-up gas): nitrogen with the same property with carrier gas. C.3.5 Internal standard: compounds which don't exist in the sample and can be separated completely from the other compositions in the chromatogram. The purity is at least 99% (mass fraction) or the known purity. For example: isobutanol, butyl cellusolve, glycol dimethyl ether, diethylene glycol dimethyl ether, etc. C.3.6 Calibration compound The calibration compounds in this standard include ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, cellosolve, cellosolve acetate, butyl cellusolve, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol butylether acetate. The purity is at least 99% (mass fraction) or the known purity. C.3.7 Diluting solvent: organic solvents used for diluting sample without any substance of disturbing test. The purity is at least 99% (mass fraction) or the known purity. For example: solvents such as acetonitrile, methanol, or tetrahydrofuran. C.4 Instrument and equipment C.4.1 Gas chromatograph is equipped with the following equipments: C The injection port of divisor and the removable inner lining of chamber of gasification. C Programmed heating controller. C Flame ionization detector (FID). C Chromatographic column: it shall be able to enough separate the measured components, such as the polydimethyl siloxane capillary column, 6% cyanopropylphenyl/ 94% dimethyl polysiloxane capillary column, polyethylene glycol capillary column or similar models. C.4.2 Sample injector: the capacity shall be at least two times of the sample size. C.4.3 Sample preparation bottle: the glass bottle of about 20mL with the sealed bottle cap. C.4.4 Scale: the accuracy is 0.1mg. C.5 Test condition of gas chromatography C.5.1 Example 1 Chromatographic column (basic column): 6%cyanopropylphenyl/94% dimethyl polysiloxane capillary column, 60m 0.32mm 1.0μm; Temperature of injection port: 250 ; Detector: FID, temperature: 260 ; Column temperature: the programmed heating temperature keeps to be 80 for 1min, then 10 /min to 230 for 15min; Flow velocity of carrier gas: 1.0mL/min; Split ratio: split stream sampling, the split ratio is adjustable; Sample size: 1.0μL. C.5.2 Example 2 Chromatographic column (confirmation column): polyethylene glycol capillary column,30m 0.25mm 0.25μm; Temperature of injection port: 240 ; 15

10 Detector: FID, temperature: 250 ; Column temperature: the programmed heating temperature keeps to be 60 for 1min, then 1 /min to 240 for 20min; Flow velocity of carrier gas: 1.0mL/min; Split ratio: split stream sampling, the split ratio is adjustable; Sample size: 1.0μL. Note: the optimal test condition of gas chromatography can be selected according to the properties of used gas chromatograph and the actual conditions of samples to be test. C.6 Test procedure All the tests process two parallel determinations. C.6.1 Chromatograph parameter optimization According to the chromatogram test conditions in C.5, the known calibration compounds shall be used for every time to optimize the apparatus in order to make their sensitivity, stability and separating effect in the best state. C.6.2 Qualitative analysis of product C The instrument parameters shall be optimized according to C.6.1. C Measurement of holding time of tested compound: The 1.0μL standard solution containing the tested compounds in the C.3.6 shall be put into and the holding time of each tested compound shall be recorded. C The tested compounds in the sample of qualitative test: The about 1g sample shall be taken and diluted with diluting solvent acetonitrile (C.3.7); the 1.0μL shall be taken into the chromatograph to determine the existence of tested object. C.6.3 Calibration C A certain amount (accurate to 0.1mg) of all kinds of standard compounds shall be put into the sample preparation bottle; the taken quality and the respective content in the sample to be tested shall be equal. Then the internal standard (C.3.5) of close quality with compound to be tested shall be taken and put into the same sample preparation bottle; the mixture shall be diluted with diluting solvent acetonitrile (C.3.7). The sample preparation bottle shall be sealed and shaken up. Then the separation and measurement are conducted under the same condition with the sample test. C Test of relative correction factor: the instrument parameters shall be optimized according to (C.6.1) specifications under the same chromatographic condition with the test sample. The appropriate amount of calibration mixture shall be put into the gas chromatograph; the chromatogram shall be recorded. The relative correction factor of each kind of compound shall be respectively calculated according to the Formula (C.1): mei Ais Ri = (C.1) mis Aci Where: R i Relative correction factor of tested compound i; m ei The quality of compound i in the calibration mixture, the unit is gram (g); m is The quality of internal standard in the sample, the unit is gram (g); A is Peak area of internal standard; A Ci Peak area of compound i. The relative deviation shall be less than 5%, and the results shall keep three effective 16

11 The relative deviation between the different laboratory test results shall be less than 20%. Annex D (Normative) Content test of led, cadmium, mercury D.1 Principle The qualitative screen by X-Ray Fluorescence Spectrometer shall be carried out on the sample to be tested, and the existence of tested element in the sample to be tested shall be determined according to the characteristic spectrum peak of the element. If the sample contains the tested elements, the film coating after drying shall adopt the feasible method to remove all organic substances and adopt appropriate analytical apparatus [such as atomic absorption spectrophotometer or inductively-coupled-plasma atomic-emission spectrograph, etc] to measure the contents of led, cadmium and mercury in the treated test solution. D.2 Reagent The test only uses the analytically pure reagent, and the water used shall meet the requirements of third-class water in GB/T D.2.1 Nitric acid: about 65% (mass fraction), the density is about 1.40g/mL; the yellow nitric acid shall not be used. D.2.2 Hydrogen peroxide: about 30% (mass fraction), the density is about 1.10g/mL. D.2.3 Magnesium carbonate. D.2.4 Nitric acid solution: 1:1 (volume fraction). D.2.5 Nitric acid solution: 2:98 (volume fraction). D.2.6 Standard solution of led, cadmium, mercury: the concentration is 100mg/L or 1000mg/L. D.3 Apparatus and equipment The ordinary-laboratory instruments and equipments as well as the following instruments and equipments: D.3.1 X-Ray Fluorescence Spectrometer: wavelength-dispersion X-Ray Fluorescence Spectrometer (WDXRF) or energy-dispersive x-ray fluorescence spectrograph (EDXRF). D.3.2 Appropriate analytical apparatus (such as atomic absorption spectrophotometer or inductively-coupled-plasma atomic-emission spectrograph). D.3.3 Breaking plant: disintegrator, scissors or other appropriate breaking plants, etc. D.3.4 Electric hot plate: the temperature is controllable. D.3.5 Muffle furnace: the temperature can be controlled in (475±25). D.3.6 Microwave digestion system. D.3.7 Scale: the accuracy is 0.1mg. D.3.8 Pot: 50mL. D.3.9 Beaker: 50mL. D.3.10 Filter membrane (is applicable to water solution): pore diameter 0.45μm. D.3.11 Volumetric flask: 25mL, 50mL, 100mL, etc. D.3.12 Pipette: 1mL, 2mL, 5mL, 10mL, 25mL, etc. D.3.13 Glass plate or polyfluortetraethylene plate. 18

12 All the glass wares, sample containers and glass plates or polyfluortetraethylene plates shall be soaked for 24H with nitric acid solution (D.2.4) before use, then shall be cleaned by water and dried. D.4 Test procedure D.4.1 Qualitative screen D The instruments shall be operated according to the X-Ray Fluorescence Spectrometer (D.3.1), and shall be warmed up according to the provisions of instrument manufacturer till instrument stabilization. D The sample to be tested shall be mixed evenly according to the construction mixture ratio (it doesn't need to add the diluents) shown on the product; after the even mixture, the appropriate amount of sample shall be put into the sample chamber of instrument. The characteristic analysis line (see Table D.1) of the elements to be tested shall be selected, and the existence of element such as led, cadmium, mercury in the sample shall be conducted the qualitative identification. If the contents of elements such as led, cadmium, mercury in the sample is lower than the detection limit of qualitative screen (see Table D.2), the following steps of test are not necessary, and the test result can be reported by the detection limit of qualitative screen. Note 1: in order for the effective test results, the analyst shall prepare the sample with the reference of the instrument operating manual or according to the minimal size/ quality/ thickness required by instrument manufacturer; generally speaking, the minimum thickness of liquid sample is 15mm. The measurement time of each sample is different according to different instrument and matrix as well as element; generally speaking, the measurement time of each sample is 30s~ 300s. Note 2: the following steps of test can be directly conducted without the test of qualitative screen. D.4.2 Preparation of film coating The sample to be tested shall be mixed evenly according to the construction mixture ratio (it doesn't need to add the diluents) shown on the product; after the even mixture, the film coatings with appropriate thickness shall be prepared on the glass plates or polyfluortetraethylene plates (D.3.13). Under the drying conditions specified in the product specification, the film coatings shall be taken after they are completely dry (the temperature of air-drying varnish shall not exceed (60±2) in case of drying) and shall be smashed by breaking plant (D.3.3) at room temperature; the sample particle diameter after smash shall not exceed 5mm. Note 1: as for the film coatings which can not be smashed (such as elasticity or plasticity film coatings), the clean scissors (D.3.3) can be used to cut up the film coatings as possible. Note 2: the sample treatment of powder sample shall be conducted directly. D.4.3 Sample treatment The two parallel determinations shall be conducted on the prepared samples. This standard supplies the following sample-digestion methods which can be adopted by laboratories according to conditions. D Dry ashing (is applicable to measuring the contents of led and cadmium in the coating samples) The 0.2g~ 0.3g (accurate to 0.1mg) samples after smash shall be taken into the pot (D.3.8); about 0.5g magnesium carbonate (D.2.3) shall be covered on the sample in the pot. Then the pot shall be put on the electric hot plate (D.3.4) in the fume hood; the temperature (not exceeding 475 ) of electric hot plate shall be increased gradually till the sample is 19

13 there is no tested elements; otherwise, the digestion conditions (for example, adding more acid liquor and hydrogen peroxide and prolonging the heat time) shall be changed to dissolve out completely the tested elements. The resulting digestion shall be tested on the day; otherwise the nitric acid (D.2.1) shall be used to stabilize and to keep the preservative solution strength c (HNO3) 1 mol/l. D.4.4 Test This standard illustrates the testing process with the example of atomic absorption spectrophotometer (for instrument working conditions, see Table D.3). The laboratories may also adopt other appropriate analytical apparatus (D.3.2) and process the operation and the test according to the relevant illustration of instrument manufacturer, but the adopted analytical apparatus shall be indicated in the test report. D Preparation of standard operation solution The appropriate measuring flask (D.3.11) and pipette (D.3.12) shall be adopted; the nitric acid solution (D.2.5) shall be used to dilute led, cadmium, mercury standard solutions (D.2.6) step by step. The preparation of the following series of standard operation solutions (the concentration range of standard operation solution may be determined according to the used instruments and test-sample conditions): Led (mg/l) : 0.0, 2.5, 5.0, 10.0, 20.0, 30.0; Cadmium (mg/l) : 0.0, 0.1, 0.2, 0.5, 1.0; Mercury (μg/l) : 0.0, 10.0, 20.0, 30.0, 40.0 Note: the series standard operation solutions shall be prepared on the day of using. D Measurement of led, cadmium, mercury content in test solution The absorbance of led and cadmium standard operation solution shall be tested respectively by flame atomic absorption spectrophotometer; the absorbance of mercury standard operation solution shall be tested by cool-steam atomic absorption spectrophotometer; the instrument will draw automatically the calibration curve according to the corresponding concentration of absorbance value. The calibration curve shall at least include one blank and three standard operation solution with the correlation coefficient 0.995, otherwise the new calibration curve shall be made again. The absorbance of test solution shall be tested in the same way. According to calibration curve and absorbance of test solution, the instrument will give out the concentration value of elements to be tested in the test solution. If the concentration of elements to be tested in the test solution is beyond the peak point of calibration curve, the nitric acid solution used in test solution shall be tested after the appropriate dilution. If the relative deviation between two test results (concentration value) is greater than 10%, the test shall be conducted again according to D.4 test procedure. D.5 Calculation result The contents of led, cadmium, mercury in the sample shall be calculated according to the Formula (D.1): ( ρ ρ0 ) V F ω = (D.1) m Where: ω The contents of led, cadmium, mercury in the sample, the unit is milligram per kilogram (mg/kg); 21

14 Annex E (Normative) Content test of sexavalent chrome E.1 Principle The film coatings after drying use the alkaline digestive solution to abstract the sexavalent chrome compounds from the sample. The sexavalent chrome in the extracting solution reacts with the diphenylcarbazide to generate the aubergine complex and the sexavalent chrome content in the test solution shall be measured by the spectrophotometric method in the places with wavelength of 540nm. E.2 Reagent and material The test only uses the analytically pure reagent, and the water used shall meet the requirements of third-class water in GB/T E.2.1 Nitric acid: about 65% (mass fraction). The density is about 140g/mL; the yellow nitric acid shall not be used. E.2.2 Vitriol: about 98% (mass fraction). The density is about 1.84g/mL. E.2.3 Sodium hydroxide. E.2.4 Anhydrous sodium carbonate. E.2.5 Dipotassium hydrogen phosphate. E.2.5 Potassium dihydrogen phosphate. E.2.7 Diphenylcarbazide. E.2.8 Anhydrous magnesium chloride. E.2.9 Acetone. E.2.10 Nitric acid solution: 1:1 (volume ratio). E.2.11 Sulphuric acid solution: 1:9 (volume ratio). E.2.12 Digestive solution: 20.0g sodium hydroxide (E.2.3) and 30.0g anhydrous sodium carbonate (E.2.4) are taken. After the dissolution with water, they are transferred into the 1000mL measuring flask and diluted to the scale, shaking up, transferring to the plastic bottle for preservation. This extracting solution shall be preserved sealing at 20 ~ 25 and shall be prepared over again every month. The ph value must be detected before use and shall be above 11.5 (including 11.5), otherwise it shall be prepared again. E.2.13 Damping fluid: 87.09g dipotassium hydrogen phosphate (E.2.5) and 68.04g potassium dihydrogen phosphate (E.2.6) are dissolved into the water and transferred into the 1000mL measuring flask and diluted to the scale. The damping fluid ph=7. E.2.14 Diphenylcarbazide developer: 0.5g diphenylcarbazide (E.2.7) shall be taken to dissolve in 100mL acetone (E.2.9), preserving in the brown bottle. In case of solution color reduction, it shall be prepared again. E.2.15 Sexavalent-chrome standard stock solution: the concentration is 100mL. E.2.16 Sexavalent-chrome standard solution: the concentration is 5mg/L. 5mL sexavalent-chrome standard stock solution (E.2.15) shall be taken with pipette (E.3.10) into the 100mL measuring flask, diluted with water to the scale. This solution shall be prepared on the day of using. 23

15 E.3 Apparatus and equipment The ordinary-laboratory instruments and equipments as well as the following instruments and equipments. E.3.1 Spectrophotometer, is applicable to measurement at places with wavelength of 540nm, is equipped with cuvette with optical path of 10mm. E.3.2 Breaking plant: disintegrator, scissors, etc. E.3.3 Stainless-steel metallic screen: the pore diameter is 0.25mm. E.3.4 Agitating heater: this device shall be able to keep the constant temperature of digestive solution at 90 ~ 9 and mix automatically and continuously; the stirring-bar outer layer shall be polytetrafluoroethylene or glass; the thermostatic oscillation water-bath can be used also at 90 ~ 95. E.3.5 Acidimeter: the accuracy is ±0.2pH unit. E.3.6 Scale: the accuracy is 0.1mg. E.3.7 Filter membrane (is applicable to water solution): the pore diameter is 0.45μm. E.3.8 Slaker: 250mL conical flask with plug or 250mL beaker with watch glass. E.3.9 Measuring flask: 25mL, 50mL, 100mL, 1000mL, etc. E.3.10 Pipette: 1mL, 2mL, 5mL, 10mL, 25mL, etc. E.3.11 Measuring cylinder: 5mL, 10mL, 25mL, 50mL, etc. E.3.12 Beaker: 250mL. E.3.13 Glass plate or polyfluortetraethylene plate. All the glass wares, sample containers and glass plates or polyfluortetraethylene plates shall be soaked for 24H with nitric acid solution (E.2.10) before use, then shall be cleaned by water and dried. E.4 Test procedure E.4.1 Preparation of film coating The sample to be tested shall be mixed evenly; samples of components shall be mixed according to proportion (not necessary to add diluents) specified in product specification; after the even mixture, the film coatings with appropriate thickness shall be prepared on the glass plate or polyfluortetraethylene plate (E.3.13); under the drying conditions specified in the product specification, the film coatings shall be taken after the total drying [the temperature of white dry paint shall not exceed (60±2) in case of drying] and shall be smashed by breaking plant (E.3.2) at room temperature. and be screened by the stainless-steel metallic screen (E.3.3) for treatment. Note 1: as for the film coatings which can not be smashed (such as elasticity or plasticity film coatings), the clean scissors (E.3.2) can be used to cut up the film coatings as possible and the sample treatment can be conducted directly without screen. Note 2: the sample treatment of powder sample shall be conducted directly. E.4.2 Sample treatment The two parallel determinations shall be conducted on the prepared samples. 2.5g smashed samples (accurate to 0.1mg) shall be taken into the slaker (E.3.8), adding about 400mg anhydrous magnesia; 50ml digestive solution (E.2.12) and 0.5mL damping fluid (E.2.13) are taken with the measuring cylinder (E.3.11) into the slaker. The digestive solution shall completely submerge the sample and may add 1~2 drops wetting agent to increase the wetting property of sample. The slaker shall be covered with plug and watch glass, putting on the agitating heater (E.3.4), mixing and heating to 90 ~ 95, and the continuous mixture at 24