Development of an innovative analytical method for forensic detection of cocaine, antidepressants, and metabolites in postmortem blood using magnetic nanoparticles

• Published in: Analytical and bioanalytical chemistry 2024-05, Vol.416 (13), p.3239-3250
• Main Authors: de Souza Schwarz, Patricia, dos Santos, Bruno Pereira, Birk, Letícia, Eller, Sarah, de Oliveira, Tiago Franco
• Format: Article
• Language: English
• Subjects: Acetic acid; Acetonitrile; Adult; Analytical Chemistry; Analytical methods; Antidepressants; Antidepressive Agents - blood; Biochemistry; Biological properties; Biological samples; Blood; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Chromatography, Liquid - methods; Citalopram; Cocaethylene; Cocaine; Cocaine - analogs & derivatives; Cocaine - blood; desorption; Ethyl acetate; Female; Fluoxetine; Food Science; Forensic science; forensic sciences; Forensic toxicology; Forensic Toxicology - methods; hematologic tests; Humans; Iron oxides; Laboratory Medicine; Limit of Detection; Liquid chromatography; liquids; magnetic materials; magnetism; Magnetite Nanoparticles - chemistry; Male; Mass spectrometry; Mass spectroscopy; Metabolites; methanol; Monitoring/Environmental Analysis; Nanoparticles; Neodymium; Permanent magnets; Public health; Research Paper; solid phase extraction; Solid Phase Extraction - methods; Solid phases; Sorbents; Substance Abuse Detection - methods; tandem mass spectrometry; Tandem Mass Spectrometry - methods; Three dimensional printing; Toxicology
• ISSN: 1618-2642; 1618-2650; 1618-2650
• DOI: 10.1007/s00216-024-05273-1

Cocaine and antidepressants rank high globally in substance consumption, emphasizing their impact on public health. The determination of these compounds and related substances in biological samples is crucial for forensic toxicology. This study focused on developing an innovative analytical method for the determination of cocaine, antidepressants, and their related metabolites in postmortem blood samples, using unmodified commercial Fe 3 O 4 nanoparticles as a sorbent for dispersive magnetic solid-phase extraction (m-d-SPE), coupled with liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) analysis. An aliquot of 100 µL of whole blood and 5 µL of the internal standard pool were added to 30 mg of nanoparticles. The nanoparticles were separated from the sample using a neodymium magnet inserted into a 3D-printed microtube rack. The liquid was then discarded, followed by desorption with 300 µL of 1/1/1 acetonitrile/methanol/ethyl acetate. The sample was vortexed and separated, and 1.5 µL of the organic supernatant was injected into the LC–MS/MS. The method was acceptably validated and successfully applied to 263 postmortem blood samples. All samples evaluated in this study were positive for at least one substance. The most frequent analyte was benzoylecgonine, followed by cocaine and cocaethylene. The most common antidepressants encountered in the analyzed samples were citalopram and fluoxetine, followed by fluoxetine’s metabolite norfluoxetine. This study describes the first report of this sorbent in postmortem blood analysis, demonstrating satisfactory results for linearity, precision, accuracy, and selectivity for all compounds. The method’s applicability was confirmed, establishing it as an efficient and sustainable alternative to traditional techniques for forensic casework.