非渗透性客体上金属印痕的显现

Detection of Metal Imprints on Non-porous Surfaces

利用2-(5-溴-2吡啶偶氮)-5-二乙氨基酚显色剂,研究非渗透性客体上金属印痕的显现。考察接触和间隔时间、客体种类和转移次数对显现效果的影响。结果表明,皮肤接触金属工具90 s后,与非渗透性客体接触超过1 s,间隔时间在1~30 d内,转移5次以内时,客体表面遗留印痕均可有效显现。该方法可用以建立起犯罪嫌疑人与金属工具的联系,灵敏简便,在法庭科学领域有较好的应用前景。

A new method of visualizing metal imprints on non-porous surfaces was studied using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol as the chromogenic reagent.The affecting factors such as contact time,time elapse from the contact to the reaction,type of substrates and transfer times were studied.The results show that imprints with good quality are obtained when the contact time is more than 1 s,the time interval is between 1~30 days and the metal imprints within 5 deposition times after the contact between hands and metal tools for 90 s.This method has the advantages of high sensitivity and easy operation and is used to establish the connection between suspects and metal tools,which has potential applications in forensic science.