Verkouteren Jennifer R
Chemical Science and Technology Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8371, USA.
J Forensic Sci. 2007 Mar;52(2):335-40. doi: 10.1111/j.1556-4029.2006.00354.x.
The sizes of explosives particles in fingerprint residues produced from C-4 and Semtex-1A were investigated with respect to a fragmentation model. Particles produced by crushing crystals of RDX and PETN were sized by using scanning electron microscopy, combined with image analysis, and polarized light microscopy was used for imaging and identifying explosive particles in fingerprint residues. Crystals of RDX and PETN fragment in a manner that concentrates mass in the largest particles of the population, which is common for a fragmentation process. Based on the fingerprints studied, the particle size to target for improving mass detection in fingerprint residues by ion mobility spectrometry (IMS) is > or = 10 microm in diameter. Although particles smaller than 10 microm in diameter have a higher frequency, they constitute < 20% of the total mass. Efforts to improve collection efficiency of explosives particles for detection by IMS, or other techniques, must take into consideration that the mass may be concentrated in a relatively few particles that may not be homogeneously distributed over the fingerprint area. These results are based on plastic-bonded explosives such as C-4 that contain relatively large crystals of explosive, where fragmentation is the main process leading to the presence of particles in the fingerprint residues.
针对一种破碎模型，研究了由C-4和Semtex-1A产生的指纹残留物中炸药颗粒的大小。通过使用扫描电子显微镜结合图像分析来测量由黑索金（RDX）和季戊四醇四硝酸酯（PETN）晶体破碎产生的颗粒大小，并使用偏光显微镜对指纹残留物中的炸药颗粒进行成像和识别。RDX和PETN晶体的破碎方式会使质量集中在群体中最大的颗粒上，这在破碎过程中很常见。基于所研究的指纹，通过离子迁移谱（IMS）提高指纹残留物中质量检测的目标颗粒大小为直径大于或等于10微米。尽管直径小于10微米的颗粒出现频率更高，但它们占总质量的比例小于20%。为提高通过IMS或其他技术检测炸药颗粒的收集效率所做的努力，必须考虑到质量可能集中在相对较少的颗粒中，且这些颗粒可能不会均匀分布在指纹区域。这些结果基于像C-4这样含有相对较大炸药晶体的塑料粘结炸药，其中破碎是导致指纹残留物中出现颗粒的主要过程。
