From crime scene to research lab: advanced characterisation techniques applied to forensic science
|Antihistamines, drugs which are crucial to prevent or mitigate allergy-related reactions, can cause intoxication and sometimes be fatal when co-administered with alcohol or sedatives. Therefore, in the toxicology and forensic science fields there is an increasing need for screening methods that can rapidly detect and quantify these substances, given also that immunoassay and colorimetric tests, largely used during field drug testing, lack the sensitivity required for low-concentration drug detection.
In the latest years, spectroscopic methods became increasingly important, due to their simplicity, non-destructiveness, and minimal sample preparation requirements. Specifically, tuning the laser excitation to the deep ultraviolet (UV) range, it is possible to selectively look for specific chromophores, such as drugs.
In a recent study, Prof. Igor Lednev (University at Albany, State University of New York), Prof. Entesar Al-Hetlani (Kuwait University) and colleagues, including Dr Barbara Rossi (Elettra Sincrotrone Trieste) tested the use of the Deep Ultraviolet Raman Spectroscopy, available at the CERIC Italian Partner facility at Elettra Sincrotrone Trieste, to detect and quantify antihistamine cetirizine in liquid and dried oral fluid samples. Moreover, they coupled these analyses with machine learning algorithms to improve the discrimination rate between samples that contained antihistamines and samples that were free of them. With this approach, researchers could detect cetirizine with a limit of detection of 50 µg/mL that could be further improved by optimizing the spectroscopic parameters including the laser wavelength.
Although it is a preliminary study and requires more donors/samples and a broader range of drug types, the research provides proof-of-concept evidence for using this analytical approach in forensic applications.
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