Forensic Mass Spectrometry

Abstract

Developments in forensic mass spectrometry tend to follow, rather than lead, the developments in other disciplines. Examples of techniques having forensic potential born independently of forensic applications include ambient ionization, imaging mass spectrometry, isotope ratio mass spectrometry, portable mass spectrometers, and hyphenated chromatography-mass spectrometry instruments, to name a few. Forensic science has the potential to benefit enormously from developments that are funded by other means, if only the infrastructure and personnel existed to adopt, validate, and implement the new technologies into casework. Perhaps one unique area in which forensic science is at the cutting edge is in the area of chemometrics and the determination of likelihood ratios for the evaluation of the weight of evidence. Such statistical techniques have been developed most extensively for ignitable-liquid residue analyses and isotope ratio analysis. This review attempts to capture the trends, motivating forces, and likely impact of developing areas of forensic mass spectrometry, with the caveat that none of this research is likely to have any real impact in the forensic community unless: (a) The instruments developed are turned into robust black boxes with red and green lights for positives and negatives, respectively, or (b) there are PhD graduates in the workforce who can help adopt these sophisticated techniques.

Analytical Validation of a Portable Mass Spectrometer Featuring Interchangeable, Ambient Ionization Sources for High Throughput Forensic Evidence Screening

“…are known for their accuracy, broad applicability, and court admissibility [8,11,12], throughput is hindered by the required preparative steps and overall duty cycle. Ambient MS techniques [13,14], which increase sample throughput by forgoing extensive sample preparations, have shown proficiency in forensic chemical analysis [15][16][17], with recent reports involving the analysis of biofluids [18,19], explosives [20], adulterated foodstuffs [21], mind-altering plant-based evidence [22], and simultaneous molecular/elemental composition [23]. Specific techniques like desorption electrospray ionization (DESI) [24], direct analysis in real time (DART) [25], and paper spray ionization (PSI) [26,27] have shown utility in both trace and bulk drug evidence analysis, particularly in combatting the rise of Bdesigner drugs^evidence and accommodating associated paraphernalia [28].…”

Lifestyle chemistries from phones for individual profiling

“…Although no approach has been developed yet to capture such lifestyle-derived skin-associated chemicals from objects, the detection of molecular traces from the skin has been used in the past and involves very sensitive techniques. Due to its superb sensitivity (14), mass spectrometry (MS) is a powerful tool widely used for forensic applications (15) by providing either molecular (16)(17)(18)(19) or elemental analysis (20)(21)(22). Specific sets of known molecules are usually targeted in forensics applications, for example, to identify traces of illicit drugs or explosives (23)(24)(25)(26).…”

Distance-of-Flight Mass Spectrometry: What, Why, and How?

“…This spatially selective detector can be identical to those found in MHMS instruments as shown in Figure 2. Just as in other spatially dispersive MS approaches, such as the MHMS, in 1 Time-of-flight mass spectrometry (TOFMS) 2 Sector-field mass spectrometry (SFMS) 3 Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) 4 Quadrupole mass spectrometry (Q-MS) 5 Quadrupole-ion trap mass spectrometry (QIT-MS) 6 Triple quadrupole mass spectrometry (QqQ-MS) 7 Distance-of-flight mass spectrometry (DOFMS) Figure 1. In 1987, Kurt Brunée imagined the Bmass-spectrometer islands^in a cartoon representation of the distinction among mass analyzers based on analyzer-specific performance characteristics [31].…”

“…An impressive but not comprehensive list of research fields outside analytical chemistry influenced by MS development includes forensics [1,2], archaeology [3], physics [4], cosmology [5][6][7], geosciences [8], atmospheric sciences [9,10], materials science [11], biosciences [12,13], and medicine [14]. Moreover, the analytical performance of modern mass spectrometers is compelling.…”