目的 汽车油漆是交通肇事案件中重要的物证之一。为了准确鉴定油漆物证中的无机填料,本文研究微区X射线衍射法在汽车油漆物证检验中的应用。方法 应用微区X射线衍射法对颜色相同的汽车漆片进行物相分析,并与扫描电镜/能谱仪和红外光谱检验结果相比较。结果 准确得出3个油漆样品的无机物质组成,不但与电镜和红外的检验结果相互印证,而且提供的物相信息更精确。结论 与普通X射线衍射法相比,该方法具有微区、微量原位检测的优点,可分析微量样品或样品上面积非常小的区域,因此在油漆及其它微量物证检验中有很好的应用前景。

Objective Car paint frequently presents in the scene of hit-and-run accident. The inorganic substances in the paint are important to characterize the paint. The integrity of information about the paint is essential for ascertainment of the accident car. In order to accurately identify the inorganic substances in car paint, this paper tries to apply micro X-ray diffraction (micro-XRD) into analyzing the inorganic constituents of the filler in car paint.Methods The analysis of three car paint samples owning same color was conducted with the micro-XRD to verify the inorganic composition. The results were compared with those obtained by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS).Results Inorganic composition, achieved by the micro-XRD from three samples, was consistent with the one by FT-IR and SEM/EDS, yet showing more accurate phase information.Conclusion Micro-XRD is a very attractive technique for paint analysis, able to discriminate the different inorganic substances in diverse paints. The method has advantages of sampling within micro area, in situ detection of minimal specimen quantity and non-destruction for the analyzed object, reaching the same or even better accuracy as that from large quantity of tested materials by the ordinary approach of X-ray diffraction. The micro-XRD, in combination with other measurements, can make different paints distinguished. Therefore, micro-XRD is very likely to hold a wide application prospect for forensic identification.