Recommendations, trends and analytical strategies applied for biological samples collection (sampling) and storage in forensic toxicology of volatile poisons (inorganic and organic)

The forensic analysis of volatile poisons, including volatile inorganic (VIP) and organic poisons (VOP), is crucial in forensic toxicology. These substances are challenging to analyse due to their instability and tendency to dissipate, requiring careful handling from sample collection to analysis. Despite their importance in public health and criminal justice, standardised guidelines for collecting and storing biological samples to detect VIP and VOP are lacking. This study reviews existing literature, identifies trends, and develops advanced strategies for effective sample collection and storage. Biological samples like blood, urine, serum, hair, saliva, and nails need customised approaches to preserve volatile analytes. Innovative techniques such as the PENVOC system and rolling stir bar sampling offer significant improvements in volatile organic compounds (VOC) analysis. The study also addresses post-mortem microbial production, complicating forensic ethanol analysis, and evaluates advanced storage methods like hydrophobic coatings, membrane-based preservation, supercritical fluid extraction, and cryogenic storage.