This standard gives methods for determining mercury content in automobile parts and materials.
X-ray fluorescence spectrometry is applicable to screening and rapid determination of mercury content in automobile materials.
Cold atomic absorption spectrometry, atomic fluorescence spectrometry, inductively coupled plasma atomic emission spectrometry or inductively coupled plasma mass spectrometry is applicable to quantitative determination of mercury content in automobile materials.
Direct mercury determination is applicable to quantitative determination of mercury content in automobile materials.
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 8170 Rules of Rounding off for Numerical Values & Expression and Judgment of Limiting Values
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
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)
EPA 7473: 2007 Mercury in Solids and Solutions by Thermal Decomposition, Amalgamation, and Atomic Absorption Spectrometry
3 X-Ray Fluorescence Spectrometry
3.1 Principle
Place the prepared sample in the sample chamber of X-ray fluorescence spectrometer and run X ray analysis on the sample in the selected analysis mode. Based on the screening limit of mercury, determine if the mercury (Hg) content in the sample is acceptable and if further testing is required.
3.2 Reagents and materials
3.2.1 Boric acid: analytically pure; subject to 1h drying at 105℃ and store in desiccator.
3.2.2 Liquid nitrogen: industrial grade.
3.2.3 Mercury-contained standards
3.3 Apparatus
3.3.1 X-ray fluorescence spectrometer
3.3.2 Cutter
3.3.3 Liquid nitrogen low-temperature pulverizer
3.3.4 Grinder: with wolfram carbide (WC) grinding tool
3.3.5 Tablet press: with a working pressure not less than 20MPa
3.4 Sample preparation
3.4.1 Preparation principle
3.4.1.1 The sample to be tested must cover the measuring window of spectrometer.
3.4.1.2 The sample's exposure side shall be able to represent the entire sample.
3.4.1.3 Attention shall be paid to preventing pollution during sample preparation.
3.4.2 Preparation method
3.4.2.1 Solid sample. If the size of the sample, the material surface of which is even and homogeneous, is suitable for X-ray fluorescence spectrometer, analyze directly. If the sample is too small, it shall be analyzed together with kin samples (e.g. small screw). If the sample is too thin, samples may be stacked to sufficient thickness (at least 5mm for polymer and aluminum/magnesium/titanium light alloys, and 1mm for other alloys).Special attention shall be paid to the consistency of sample thickness and homogeneity of composition. To spread the sample flatly and evenly for analysis, inside lining materials, the backgrounds of which shall be as low as possible, may be added for supporting.
