利用碘-苯黄酮和四氧化钌喷涂剂显现潜在指纹信息的研究

Research of Iodine-Benzoflavone and Ruthenium Tetroxide Spray Reagents for the Latent Finger marks

本文利用2种喷涂试剂,碘-苯黄酮和四氧化钌(RTX)与传统刷粉技术显现潜在指纹信息,做了比对评价。不是所有客体表面的指纹和陈旧痕迹,都同时适用于喷涂和刷粉技术,如玻璃和木制家具上的指纹显现,刷粉技术仍然是首选。而喷涂技术用于壁纸、乙烯基材料和地砖上的指纹显现效果较好。注意:刷粉或氰基丙烯酸酯(用罗丹明6G染色)熏显技术与RTX喷涂技术不能同时使用,因为这2类药物不相容。但在使用刷粉技术之前或之后,再用碘-苯黄酮喷涂,指纹显现效果较好,而碘-苯黄酮与氰基丙烯酸酯不能同时使用。在碘-苯黄酮配方中,使用HFC4310mee和HFE7100两种溶解剂与原配方中的CFC113溶解剂相比,没有发现差异。但CFC113含有氟利昂,严重污染环境,所以推荐使用HFC4310mee作为理想的替换试剂。由于RTX喷涂剂比较昂贵,目前正在寻找与RTX相媲美且廉价的化学试剂,同时使用寿命在2个月以上。对于不同的客体表面,依据指纹的陈旧性,推荐使用以下技术:刷粉适用于玻璃和木制家具上的所有陈旧指纹,指纹的陈旧性在3天或更长一点时间;碘-苯黄酮喷涂适用于壁纸、乙烯基材料、地砖和粗糙的原木上;RTX喷涂适用于壁纸和油漆上的新鲜指纹,而指纹陈旧性在1天以内。

The performance of two spray reagent, iodine-benzoflavone and ruthenium tetroxide （RTX）, was evaluated and compared with the conventional powdering technique currently used at the crime scene. Neither the spray techniques nor powdering were shown to be suitable for all surface and ages of marks tested. On some surfaces such as glass and treated wood, powdering was still the superior technique, whereas the spray techniques produced better development on wallpaper, vinyl, and brick. Sequencing work showed that RTX was incompatible with powdering and cyanoacrylate （with a rhodamine 6G）. Iedine-benzoflavone can be used successfully either before or after powdering in a sequence; however, it was incompatible with cyanoacrylate. Two non-CFC formulations of iodine-benzoflavone using HFCA310mee and FHE7100 solvents were tested and shown not to be as effective as the original Arklone （CFC-113） formulation; however, the HFCA310mee solvent is recommended as most suitable replacement solvent. Due to the expense of the commercial RTX spray, attempts at formulating a more cost-effective version were also carried out. A formulation was developed that gave comparable development to the commercial version but at a much cheaper cost, and with a shelf life of up to two months. Recommendations are presented for which techniques are suitable for different surfaces and ages of marks. Shown to be the best technique on all ages of marks tested on treated wood, glass, and also on marks ages three days and older on paint. Iedine-benzoflavone was the best technique on wallpaper, vinyl, brick, and raw wood. RTX was the best detection technique for fresh marks and marks aged up to one day on wallpaper and paint.