Application of Static Secondary Ion Mass Spectrometry to Trace Evidence Analysis

摘要

State-of-the-art secondary ion mass spectrometry (SIMS) instrumentation was applied to the characterization of samples representative of trace evidence. The purpose of the study was to assess the efficacy of static SIMS for providing highly specific chemical characterization of trace evidence samples. It was found that samples coated with automotive paint and with nail polishes could be distinguished based on their SIMS spectra, provided the data was reduced using multivariate analysis techniques. It was also found that hair samples could be readily characterized in terms of the consumer chemicals present on the surface, namely, soap and softener chemicals. Other studies showed that the drugs of abuse heroin and cocaine could be readily detected on fiber surfaces using SIMS. In order to perform the hair and fiber studies, methods for analyzing hair and fiber samples required development. On the basis of these studies, it was concluded that the technique has the potential for providing a chemical-specific characterization for a variety of trace evidence characterizations. At the present time, limitations of the technique are the high cost of the instrumentation. and the high level of expertise required for routine operation, and more importantly, data interpretation.