An Easy to Implement Approach for Laboratories to Visualize Particle Spread During the Handling and Analysis of Drug Evidence.

Recent work has shown that detectable levels of drugs exists on nearly all surfaces within a forensic laboratory - especially within the drug chemistry unit. This is an expected occurrence due to the handling and opening of drug evidence that contains powder material. The process of opening evidence, which produces aerosolized particulate that can settle on surfaces throughout the lab, has never been visualized. This work presents the first attempt to visualize the spread of particulate throughout the laboratory during the analysis of drug evidence and introduces an easy to implement approach laboratories can use to evaluate their specific protocols. By creating two simulated bricks of drugs that contained fluorescent particles, the spread of particulate was able to be monitored throughout the evidence handling process up to and including cleaning of surfaces after analysis. The protocols in this work, showed the spread of particulate, prior to cleaning, to be quite extensive, with transfer onto surfaces and items that were handled. In this study, cleaning with methanol after processing the evidence was shown to be effective at removing nearly all particulate that was released in the process. The use of visualization techniques such as this demonstrate promise for helping laboratories identify processes in their own protocols that may contribute to drug background levels and educate forensic chemists how trace residues spread.