Wright Diana M, Bradley Maureen J, Mehltretter Andria Hobbs
Federal Bureau of Investigation, Laboratory Division, 2501 Investigation Parkway, Quantico, VA, 22135.
J Forensic Sci. 2013 Mar;58(2):358-64. doi: 10.1111/1556-4029.12074. Epub 2013 Mar 12.
Comparative analyses of 50 single-layer white architectural paints were conducted to determine the discrimination power using standard techniques and to provide a basis for assessing significance when paints with limited features are not discriminated. Utilizing Fourier transform infrared spectroscopy (FTIR), 68 undifferentiated pairs resulted, yielding a discrimination of 94.45%. Adding stereomicroscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and backscatter electron (BSE) imaging, and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), the overall discrimination was 99.35%. The study included blind verification replicates, which resulted in the only pairs without indications of physical or chemical differences. The remaining groups of undifferentiated samples contained subtle differences by at least one technique, but were considered undifferentiated for the discrimination power evaluations. This study demonstrates a high degree of discrimination of single-layer white architectural paints using methods of analysis often encountered in forensic science laboratories.
对50种单层白色建筑涂料进行了比较分析，以使用标准技术确定鉴别能力，并为评估在具有有限特征的涂料无法区分时的显著性提供依据。利用傅里叶变换红外光谱（FTIR），得到了68对无法区分的涂料，鉴别率为94.45%。增加体视显微镜、带能谱（EDS）和背散射电子（BSE）成像的扫描电子显微镜（SEM）以及热解气相色谱/质谱联用仪（Py-GC/MS）后，总体鉴别率为99.35%。该研究包括盲法验证重复实验，结果得到了唯一没有物理或化学差异迹象的涂料对。其余未区分的样品组通过至少一种技术存在细微差异，但在鉴别能力评估中被视为未区分。本研究表明，使用法医学实验室中常见的分析方法对单层白色建筑涂料具有高度的鉴别能力。
