Cyanide is a poison widely used in cases of suicide or homicide. Although various methods to identify and quantify this substance are reported in the literature, they are mainly validated on biological fluids (e.g., blood and urine). In the present study, the Anion-Exchange Liquid Chromatography with Pulsed Amperometric Detection (IC-PAD) method was validated on blood and, for the first time, on gastric content, and organs (brain, lung, and liver). For each matrix, linearity, accuracy, precision, limit of detection (LOD), lower limit of quantification (LLOQ), matrix interferences, and carryover were assessed. The samples were extracted by steam distillation in acid environment for the following analysis by IC-PAD. Furthermore, cyanide values found in two real poisoning cases are reported. For each investigated matrix, the analytical method satisfied all acceptance criteria for validation: it showed a good precision and accuracy, selectivity, and sensitivity with no carryover and matrix interference. The extraction by steam distillation in acid environment REDUCED the interference of the matrices and ALLOWED to perform the analysis with good precision and accuracy. In case #1, analysis showed a blood cyanide concentration of 0.99 mu g/ml. In case #2, cyanide concentrations were 1.3 mu g/g in brain, 0.8 mu g/g in lung, 1.6 mu g/g in liver, and 1.2 mu g/g in gastric content. The cyanide concentrations found in the two reported cases have been suitable to cause death by poisoning.

Background/Objectives: I Paliperidone is an antipsychotic recently added into the market in various formulations. There are few data about safety and on therapeutic, toxic, or lethal blood concentrations. Currently, the published analytical methods are often applied to serum or plasma that are not obtained from cadaveric blood. Alternatively, aliquots of high volume of whole blood are used, but often in forensic investigations using samples at very small quantities. The aims of the present study were (a) to develop an analytical method to detect and quantify paliperidone in whole blood using only a small sample volume (10 µL) and (b) to summarize data on post-mortem blood analysis obtained from authentic autopsy cases. Methods: Method validation was carried out on 10 µL of whole blood, extracted by LLE and analyzed by LC-MS. Paliperidone concentrations obtained from blood analysis of 16 authentic autopsy cases were reported. Results: The method showed a good linearity and sensitivity, a normal distribution, the absence of anomalous values, an interday RSD% always less than 10%, and an 80–120% recovery, as required by AAFS guidelines. Femoral blood concentrations obtained from authentic autopsy cases ranged between 23.4 and 146.9 ng/mL. Conclusions: This method is to be used properly in all cases where it is necessary (a) to monitor the therapeutic adherence of patients, (b) to establish the psycho-physical conditions of the treated subject at the time of the death, and (c) to ascertain if the drug may have played a causal role in the obitus. This study reported the first data obtained from post-mortem investigation of subjects treated with paliperidone LAI. Cadaveric blood concentrations could be higher than ante-mortem reference values due to post-mortem redistribution.

Background: Postmortem redistribution (PMR) is a major challenge in forensic toxicology, particularly when drug concentrations are measured in central blood rather than peripheral blood. Although peripheral blood remains the preferred specimen for postmortem interpretation, it is not always available in routine forensic practice. Methods: This retrospective descriptive study evaluated postmortem central blood drug findings from judicial autopsies analyzed at the Forensic Toxicology Laboratory of the University of Catania between 2017 and 2024. Approximately, 700 forensic toxicological investigations were reviewed. Overall, 52 therapeutic drugs were identified, resulting in a final dataset of 313 individual drug findings. For each finding, central blood concentrations were compared with published reference ranges and cautiously classified as normal/therapeutic, high but non-toxic, toxic, or potentially lethal. Results: Most findings were classified as normal/therapeutic (84.3%), while 28 (8.9%) were high but non-toxic, 15 (4.8%) toxic, and 6 (1.9%) potentially lethal. The distribution remained broadly consistent in sensitivity analyses restricted to drugs represented by more than 3, 5, or 8 findings. In cases with toxic or potentially lethal findings and available paired peripheral blood data, observed C/P ratios were moderate, ranging from 1.07 to 2.15. Conclusions: These findings do not indicate that central blood can replace peripheral blood or that PMR can be disregarded. However, they suggest that central blood drug concentrations are not intrinsically uninterpretable and may retain practical forensic value when interpreted cautiously within the broader medico-legal context. Central blood results should not be used in isolation to diagnose poisoning, estimate the ingested dose, or reconstruct exact ante mortem concentrations.