Differentiation of Body Fluid Stains Using a Portable, Low-Cost Ion Mobility Spectrometry Device-A Pilot Study

Area of Science:

• Forensic Science
• Analytical Chemistry
• Biotechnology

Background:

• Crime scene investigation faces bottlenecks in identifying and recovering biofluid evidence.
• Current methods rely on presumptive tests and lab-based analysis, which are time-consuming and can be destructive.

Purpose of the Study:

• To develop and validate a portable ion mobility spectrometry device for in situ analysis of human biofluids.
• To demonstrate the device's capability in detecting, identifying, and discriminating common body fluids from interferences.

Main Methods:

• Utilized a small, portable ion mobility spectrometry device with a dual micro disc pump.
• Analyzed volatile organic compounds released by gentle heating of samples at ambient conditions.
• Employed unsupervised Principal Component Analysis (PCA) machine learning for sample categorization.

Main Results:

• The device successfully generated characteristic mobility spectra for biofluid samples.
• Blood and urine were accurately separated from three visually similar interferences.
• The unsupervised PCA model achieved no misclassified samples, demonstrating high discrimination.

Conclusions:

• The portable ion mobility spectrometry device offers a promising solution for rapid, in situ biofluid identification.
• This technology has the potential to streamline crime scene investigation workflows, reducing reliance on destructive presumptive tests.
• The device can provide instant identification, addressing the current bottlenecks in evidence detection, recovery, and analysis.