3-in-1 Solution for Mobile Forensic Applications

Význam tématu

Accurate and rapid in-field forensic analysis is critical for timely decision making in crime scene investigations. Direct sampling of vapors, liquids and solids reduces sample handling and preserves evidence integrity. The development of portable GC/MS systems equipped with versatile sampling accessories enhances capability to detect drugs of abuse, accelerants, and explosives on site.

Cíle a přehled studie / článku

This application note demonstrates a “3-in-1” solution for mobile forensic use provided by the Agilent 5975T LTM GC/MS when configured with a Capillary Trap Sampler (CTS) and a Thermal Separation Probe (TSP). The objectives are to showcase sampling across gas, liquid, and solid matrices, streamline preparation, and achieve lab-quality data in the field.

Použitá instrumentace

• Agilent 5975T Low Thermal Mass (LTM) Gas Chromatograph/Mass Spectrometer
• Capillary Trap Sampler (CTS) accessory based on SnifProbe technology
• Thermal Separation Probe (TSP) for direct thermal desorption
• Microvial traps for capillary columns

Použitá metodika

The CTS collects airborne volatiles by pumping air through short coated capillary columns. Up to six 20 mm trapping columns can be loaded and then transferred in disposable microvials for thermal desorption via TSP. Liquids and solids require no preparation: blood is directly sampled with TSP, while solid powders are placed in the microvial. Samples are desorbed in a heated split/splitless inlet and analyzed by fast temperature-programmed GC/MS.

Hlavní výsledky a diskuse

Gas phase sampling: Comparison of gasoline standard and fire debris vapor showed matching aromatic profiles at characteristic m/z 91, confirming gasoline presence in charred material.

Liquid phase sampling: Analysis of a 3 µL whole blood sample from an overdose victim required no cleanup. Baseline was smooth, fatty acid peaks were evident, and minor drug peaks were resolved using deconvolution software, achieving detection limits ~5 ng/µL for over 94 % of target drugs.

Solid phase sampling: Direct analysis of DNT explosive isomers yielded clear total ion chromatograms, allowing straightforward identification of energetic materials without solvent or cleanup.

Přínosy a praktické využití metody

• Elimination of extensive sample preparation and solvent washes
• Rapid on-site detection in gas, liquid, and solid forms
• Portable lab-quality data for forensic decision support
• Reduced risk of sample contamination and loss

Budoucí trendy a možnosti využití

Integration of advanced data deconvolution and library searching will enhance sensitivity and selectivity. Miniaturization of GC/MS hardware and development of novel sorbent materials for CTS columns will expand volatile sampling capabilities. Coupling with wireless data transmission and AI-driven interpretation can further accelerate field analysis.

Závěr

The 5975T LTM GC/MS combined with CTS and TSP offers a versatile 3-in-1 forensic sampling platform. It delivers fast, reliable analysis of vapors, liquids, and solids directly at the crime scene, simplifying workflows and improving evidentiary outcomes.

Reference

1. S. Zhao, Fast Analysis of Fire Debris Using an Agilent 5975T LTM GC/MSD with CTS, Agilent publication number 5991-3439EN.
2. S. Zhao, A rapid method for detection of drugs of abuse in blood samples using the thermal desorption probe and the 5975T LTM GC/MS, Agilent publication number 5991-0333EN.