Interpol review of toxicology 2016-2019

Surface Analysis Techniques in Forensic Science: Successes, Challenges, and Opportunities for Operational Deployment

Surface analysis techniques have rapidly evolved in the last decade. Some of these are already routinely used in forensics, such as for the detection of gunshot residue or for glass analysis. Some surface analysis approaches are attractive for their portability to the crime scene. Others can be very helpful in forensic laboratories owing to their high spatial resolution, analyte coverage, speed, and specificity. Despite this, many proposed applications of the techniques have not yet led to operational deployment. Here, we explore the application of these techniques to the most important traces commonly found in forensic casework. We highlight where there is potential to add value and outline the progress that is needed to achieve operational deployment. We consider within the scope of this review surface mass spectrometry, surface spectroscopy, and surface X-ray spectrometry. We show how these tools show great promise for the analysis of fingerprints, hair, drugs, explosives, and microtraces.

Spot tests: past and present

Microchemistry, i.e., the chemistry performed at the scale of a microgram or less, has its roots in the late eighteenth and early nineteenth centuries. In the first half of the twentieth century a wide range of spot tests have been developed. For didactic reasons, they are still part of the curriculum of chemistry students. However, they are even highly important for applied analyses in conservation of cultural heritage, food science, forensic science, clinical and pharmacological sciences, geochemistry, and environmental sciences. Modern pregnancy tests, virus tests, etc. are the most recent examples of sophisticated spot tests. The present ChemTexts contribution aims to provide an overview of the past and present of this analytical methodology.

Optimized and Validated DBS/MAE/LC–MS Method for Rapid Determination of Date-Rape Drugs and Cocaine in Human Blood Samples—A New Tool in Forensic Analysis

The aim of this work was to develop a new method for the determination of selected substances from the date-rape drugs group: ketamine, benzodiazepines and cocaine. The method is based on the dried blood spot method which seems to be a suitable tool in the analysis of tested substances. The extraction process based on microwave-assisted extraction was optimized to enable optimal conditions for the isolation of a wide range of analytes from blood samples collected on DBS cards. The extraction with ethyl acetate with a buffer of pH = 9 carried out at a temperature of 50 °C for 15 min ensured high extraction efficiency of the tested analytes. The optimized method was validated. Limits of detection (LOD = 4.38–21.1 ng/mL) and quantification (LOQ = 14.6–70.4 ng/mL), inter- and intra-day precision (CV = 1.37–13.4% and 3.39–14.8%, respectively), recovery (RE = 93.0–112.4%) and matrix effect (ME = 98.4–101.6%) were determined. The validation results indicate the possibility of using the proposed method in the analysis of real blood samples collected from victims of sexual assault.

Suspect Screening of Fentanyl Analogs Using Matrix-Assisted Ionization and a Miniature Mass Spectrometer with a Custom Expandable Mass Spectral Library

The reliable identification of fentanyl and its analogs is of great significance for public security. However, with the growing prevalence of fentanyl compounds, current analytical strategies cannot fully meet the need for fast and high-throughput detection. In this study, a simple, rapid, and on-site analytical protocol was developed based on a miniature mass spectrometer. A dramatically simplified workflow was implemented using matrix-assisted ionization, bypassing complex sample pretreatment and chromatographic separation. The tandem mass spectrometry (MS/MS) capability afforded by the miniature ion trap mass spectrometer facilitated the investigation of fragmentation patterns for 49 fentanyl analogs during collision-induced dissociation, revealing valuable information on marker fragment ions and characteristic neutral loss. Calculations on Laplacian bond order values further verified the mass spectrometric behavior. A computation-assisted expandable mass spectral library was constructed in-house for fentanyl compounds. Smart suspect screening was carried out based on the full-scan MS and MS/MS data. The present study demonstrates an appealing potential for forensic applications, enabling streamlined screening for the presence of illicit fentanyl compounds at the point of seizures of suspect samples.