Dust as a collection media for contaminant source attribution

Area of Science:

• Forensic Science
• Environmental Chemistry
• Analytical Chemistry

Background:

• Source attribution profiles (SAPs) are crucial for identifying the origin of chemical exposures.
• Investigating novel media for effective SAP collection and retention is essential for forensic applications.

Purpose of the Study:

• To evaluate dust as a viable medium for collecting and retaining source attribution profiles (SAPs).
• To assess the stability and distinctiveness of SAPs in dust after exposure to various chemical agents and environmental conditions.

Main Methods:

• Dust samples were exposed to organophosphate pesticides and chemical warfare agent (CWA)-related compounds in controlled conditions.
• Dust aliquots were analyzed at different time points (1h, 24h, 72h) using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS).
• Principal components analysis (PCA) was employed to differentiate and associate chemical profiles based on dust exposure.

Main Results:

• Dust samples clearly differentiated between distinct chemical exposure sources across all collection times.
• Samples exposed to the same chemical source showed clear associations, confirming reproducibility.
• Chemical signatures in dust remained stable for up to 24 hours under elevated temperature (90°C) and were less affected by elevated pH (10).

Conclusions:

• Dust serves as an effective medium for the in situ collection and retention of source attribution profiles.
• The stability of SAPs in dust under varying conditions supports its utility in forensic investigations.
• This study validates dust's potential for identifying chemical sources in real-world scenarios.