This standard specifies the methods for determining the hexavalent chromium content in automobile parts and materials. Among them,
"X-ray fluorescence spectrometry" is applicable for screening and fast determining the hexavalent chromium content in automobile materials using X-ray fluorescence spectrometry.
"Qualitative test on hexavalent chromium in anti-corrosive metal coating" is applicable for determining the existence of hexavalent chromium in anti-corrosive coating of automobile using spot method and boiling extraction method. "Determination of hexavalent chromium content in anti-corrosive metal coating" is applicable for determining the hexavalent chromium content in anti-corrosive coating using boiling extraction method and colorimetry. The two methods are applicable to coating without additional covering layers (such as oil film, water-based or solvent-based polymer film or waxy film).
"Determination of hexavalent chromium content in polymer material and electronic material" is applicable for determining the hexavalent chromium content in polymer materials and electronic materials using alkali liquor extraction method and colorimetry, but not applicable to PE and EVAC materials. The hexavalent chromium content in other automobile materials, such as glass, ceramics, fabric, and paint coating, is determined by reference to this method.
"Determination of hexavalent chromium content in leather" is applicable for determining the hexavalent chromium content in leather using phosphate solution extraction method and colorimetry.
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 1839 Steel Product Zinc Coating Mass Testing Method (GB/T 1839-2008, ISO 1460:1992, MOD)
GB/T 8170 Rules of Rounding Off for Numerical Values & Expression and Judgment of Limiting Values
GB/T 20017 Metallic and Other Non-organic Coatings—Determination of Mass per Unit Area—Review of Gravimetric and Chemical Analysis Methods (GB/T 20017-2005, ISO 10111:2000, IDT)
GB/T 30512-2014 Requirements for Prohibited Substances on Automobiles
GB/Z 21277-2007 Rapid Screening of Lead, Mercury, Chromium, Cadmium and Bromine of Regulated Substances in Electrical and Electronic Equipment—X-ray Fluorescence Spectrometry
QB/T 2262-1996 Terms for Leather Industry
QB/T 2706 Leather—Chemical, Physical and Mechanical and Fastness Tests—Sampling Location (QB/T 2706-2005, ISO 2418:2002, MOD)
IEC 62321:2008 Ed.1.0 Electrotechnical Products—Determination of Levels of Six Regulated Substances (Lead, Mercury, Cadmium, Hexavalent Chromium, Polybrominated Biphenyls, Polybrominated Diphenyl Ethers)
ISO 3613:2000 Chromate Conversion Coatings on Zinc, Cadmium, Aluminium—Zinc Alloys and Zinc-Aluminium Alloys—Test Methods
EN ISO 17075:2007 Leather—Chemical Tests—Determination of Chromium(6) Content
3 X-Ray Fluorescence Spectrometry
3.1 Principle
Put the prepared sample into the sample room of X-ray fluorescence spectrometry; carry out X-ray fluorescence spectrometric analysis on the chromium content in the sample according to the analysis mode selected, and judge whether the chromium content conforms to the screening limit, and whether accurate determination is necessary.
Note: the result obtained by X-ray fluorescence spectrometric analysis is the total chromium in the sample, rather than the hexavalent chromium.
3.2 Reagents and materials
3.2.1 Boric acid: guaranteed reagent, baking 1h at 105℃ and storing in the dryer.
3.2.2 Anhydrous lithium tetraborate: guaranteed reagent, baking 4h at 700℃ and storing in the dryer.
