Royal Canadian Mounted Police (RCMP) Technological Crime Branch (TCB), Ottawa, ON, Canada.
Forensic Sci Int. 2012 Jan 10;214(1-3):88-95. doi: 10.1016/j.forsciint.2011.07.022. Epub 2011 Aug 5.
With advancements in technology allowing for the miniaturization of consumer electronics, criminal investigations of all types frequently involve the forensic examination of electronic devices, such as cellular telephones, smartphones, and portable flash memory; in some extreme, violent cases, these devices are found covered in blood. Due to the complexity of such devices, standard operating procedures for the complete removal of blood had not previously been established by the Royal Canadian Mounted Police prior to this study. The electronics industry has adopted the use of the ultrasonic cleaner for sanitizing printed circuit boards (PCBs) by removing residues and contaminants. High frequency sound waves created by the machine penetrate and remove dirt and residues; however, early research during the 1950s recorded these sound waves breaking the internal bonds of integrated circuit chips. Experimentation with modern ultrasonic technology was used to determine if internal components were damaged, as well as if ultrasonic cleaning was the most suitable method for the removal of dried and liquid blood from a PCB. Several disinfectant solutions were compared against the 0.5% Triton(®) X-100 detergent solution in the ultrasonic cleaner, including: 10% sodium hypochlorite bleach, 85% isopropyl alcohol, and Conflikt(®) disinfectant spray. The results not only demonstrated that the ultrasonic cleaner did not damage the vital memory chip on the PCB, but also, with the assistance of Conflikt(®), was able to remove all traces of blood as indicated by Hemastix(®) reagent strips. Of five methods experimented with, two cycles of ultrasonic cleaning followed by sanitization with Conflikt(®) proved to be the only procedure capable of removing all traces of blood, as confirmed with both Hemastix(®) reagent strips and the hemochromogen test.
随着技术的进步,消费电子产品越来越小型化,各种类型的犯罪调查经常涉及对电子设备的法医检查,例如移动电话、智能手机和便携式闪存;在某些极端的暴力案件中,这些设备被发现沾满了鲜血。由于这些设备的复杂性,在此项研究之前,加拿大皇家骑警尚未制定完整清除血液的标准操作程序。电子行业已经采用了超声波清洗机来清洁印刷电路板(PCB),以去除残留物和污染物。机器产生的高频声波穿透并清除污垢和残留物;然而,早在 20 世纪 50 年代的早期研究就记录了这些声波破坏了集成电路芯片的内部键合。使用现代超声波技术进行了实验,以确定内部组件是否损坏,以及超声波清洗是否是从 PCB 上清除干燥和液态血液的最合适方法。几种消毒剂溶液与 0.5% Triton(®) X-100 清洁剂在超声波清洗机中的效果进行了比较,包括:10%次氯酸钠漂白剂、85%异丙醇和 Conflikt(®)消毒剂喷雾。结果不仅表明超声波清洗机没有损坏 PCB 上至关重要的存储芯片,而且在 Conflikt(®)的协助下,能够去除 Hemastix(®)试剂条指示的所有血迹痕迹。在实验的五种方法中,两次超声波清洗循环,然后用 Conflikt(®)进行消毒,被证明是唯一能够去除所有血迹痕迹的程序,Hemastix(®)试剂条和血色素测试都证实了这一点。