Accurately identifying and differentiating the types of injuries in decomposed corpses is a major challenge in forensic identification. Forensic investigations involving decomposed cadavers pose challenges in determining the cause of death. Traditional methods often lack conclusive evidence. However, the implementation of advanced analytical techniques, such as comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOF/MS), shows promise in overcoming these limitations, but the potential in this area remains limited. Therefore, this study aims to bridge this gap by exploring the potential of GC × GC-TOF/MS in the analysis of volatile organic compounds (VOCs) changes within decaying ante- and post-mortem injuries.The research emphasizes the forensic significance of VOCs changes in decomposed cadavers. We used GC × GC-TOF/MS analysis to identify the specific volatile compounds in putrefied corpse tissue samples from mice. The GC × GC-TOF/MS analysis results showed that under winter conditions, PC1 explained 57.16% of the variance, and PC2 explained 25.23% of the variance; while under summer conditions, PC1 explained 71.89% of the variance, and PC2 explained 24.49% of the variance. This demonstrates the potential of GC × GC-TOF/MS in identifying specific VOCs present in tissue samples that can serve as potential biomarkers for distinguishing between antemortem and postmortem injury. GC × GC-TOF/MS analysis revealed distinct VOC patterns in both conditions. Comprehensive use of GC × GC-TOF/MS analysis enhances accuracy in identifying and characterizing ante- and post-mortem injuries in decomposed cadavers. This study can significantly contribute to the field of forensic medicine and improve the accuracy of forensic investigations.

The verification of exposure to nerve agents is a serious challenge, especially in cases of soman (GD) poisoning. Protein adducts are reliable biomarkers, that provide forensic information and evidence during incidents of terrorism or sporadic poisoning. Mass spectrometry, coupled with a proteomics approach, was established for the forensic analysis of GD-based protein adducts. The fragmentation pathways of GD-based protein adducts were investigated for the first time using electrospray ionization tandem mass spectrometry. Three abundant natural loss product ions, [M+2H-54]2+ (loss of two carbon cations), [M+2H-72]2+ (loss of tert-butyl and methyl moieties), and [M+2H-84]2+ (loss of the pinacolyl moieties), were observed in each of the GD-labeled adducts, and the product ions were independent of protein structure and exposure route. A unique mechanism for the formation of product ions involving GD-protein adducts is proposed here. These findings support the development of a simple and precise forensic analysis technique to rapidly verify GD poisoning using these three GD-related product ions.

The autosomal short tandem repeat (STR) plays a unique role in population comparisons, phylogenetic reconstruction and migration history tracing. This study investigated the frequencies of 17 autosomal STR loci in the Han population from Wuxi, Eastern China, with the aim of expanding the available population information in human genetic databases and for forensic DNA analysis. The genetic polymorphisms of 17 STR loci were analysed in 5358 individuals of the Han population from Wuxi, Eastern China. Population comparisons including genetic distances, the neighbour-joining tree and multidimensional scaling plot were carried out between the Wuxi Han population and different ethnic groups. A total of 777 alleles at 17 autosomal STR loci were observed, with the corresponding allelic frequencies ranging from 0.0001-0.5210. The combined power of discrimination and exclusion for the 17 autosomal STR loci were 0.0000 and 0.000, respectively. Moreover, the phylogenetic analysis was performed between the Wuxi Han population and other relevant populations. The neighbour-joining tree and multidimensional scaling plot were generated based on Nei\'s standard genetic distance. Population comparisons indicated that the Wuxi Han population had the closest genetic relationship with the Hubei Han population, relative to the other populations, which mirrors the historical and geographical background of the populations compared.

BACKGROUND: Current chromatographic methods applied for the forensic analysis of methamphetamine are costly, time-consuming, and require complicated pretreatment procedures. Thus, the rapid detection of methamphetamine is a critical and unmet need. In this study, a surface plasmon resonance (SPR) system based on indirect inhibitive immunoassay was designed for the analysis of methamphetamine in forensic oral fluid samples.
METHODS: For the inhibition immunoassay, the diluted oral fluid was mixed with methamphetamine antibody and then injected into the SPR sensor chip. The biosensor chip was constructed by covalently immobilizing of methamphetamine-bovine serum albumin conjugate onto a carboxymethyl dextran surface at an optimized pH. The concentration of antibody was also optimized.
RESULTS: The SPR biosensor showed good sensitivity with a limit of detection of 0.44 ng/mL and was comparable or lower than the pre-existing methods. The method was finally tested using oral fluid samples from 20 suspected drug abusers in forensic cases, and it provided an acceptable recovery of 113.2%, indicating good anti-interference capability of the SPR sensor.
CONCLUSIONS: The SPR biosensor was rapid, reproducible, and had a great potential approach for the forensic detection of methamphetamine.

Recently, inorganic low explosives, such as pyrotechnic composition, black powder, and ammonium nitrate, are commonly used in improvised explosive devices (IEDs) by the rioter or terrorists since these energetic materials can be obtained easily and legally from civilian markets. Identification of inorganic oxidizing salts in these homemade explosives, including nitrates, chlorates, and perchlorates, is a necessary procedure for forensic investigators to provide criminal evidences. In this article, Fourier transform infrared (FTIR) spectroscopy was used to discriminate NO3-, CO32-, ClO3-, ClO4-, SO42-, and NH4+, whose characteristic absorption bands were explained by vibration modes of the covalent bonds. Then the spectral absorption features of nitrate salts with monovalent or divalent cations were discussed. Furthermore, it was studied whether nitrates or perchlorates can be unequivocally distinguished with the presence of carbonate and sulfate impurities through FTIR technique. Finally, the feasibility of this method was verified through an analytical case of homemade explosives.

Rapid field screening is enormously important in forensic analysis of explosives. In this article, we used a methodology based on a strong red-fluorescent europium-organic framework (Eu-MOF) material for sensitive and selective detection of picric acid, TNT, and tetryl using the fluorescence quenching effect. Results indicate that Eu-MOF can be used for the visual detection of these three explosives with low detection limits (20-140 μg/mL) and high quenching efficiency (Ksv > 104 M-1). Furthermore, this material can be recycled just by washing it with ethanol. The fluorescence quenching mechanism is also discussed. Importantly, we prepared a portable test strip that can be used for sensing TNT, and using this, we achieved a rapid field test for explosives. Consequently, Eu-MOF is a promising candidate material for use as an explosive optical sensor.

The genetic polymorphisms of 15 autosomal short tandem repeat (STR) loci were analyzed in 449 individuals of the Uygur population from Ili Kazakh Autonomous Prefecture, Northwestern China. Phylogenetic analysis was performed among the Ili Uygur population and other relevant populations. The neighbor-joining tree and multidimensional scaling plot were generated based on the Nei\'s standard genetic distance. We found a total of 173 alleles with corresponding frequencies ranging from 0.5022 to 0.0011. The combined powers of discrimination and exclusion for the 15 autosomal STR loci were 0.99999999985 and 0.99999880065, respectively. Population comparisons indicated that the Ili Uygur population had a relatively close genetic relationship with the Uygur populations from other regions of China. The pairwise genetic distance and P-values between Ili Uygur and 10 published populations showed that no statistically significant differences existed between the Ili Uygur population and the Kashi, Kashgar, and Kotan Uygur. Therefore, the Ili Uygur population has its own unique Uygur genetic characteristics that were different from the other ethnic populations of China.

OBJECTIVE: We investigated the frequencies of 15 autosomal STR loci in the Kazak population of the Ili Kazak Autonomous Prefecture with the aim of expanding the available population information in human genetic databases and for forensic DNA analysis.
METHODS: Genetic polymorphisms of 15 autosomal short tandem repeat (STR) loci were analysed in 456 individuals of the Kazak population from Ili Kazakh Autonomous Prefecture, northwestern China.
RESULTS: A total of 173 alleles at 15 autosomal STR loci were found; the allele frequencies ranged from 0.5022-0.0011. The combined power of discrimination and exclusion statistics for the 15 STR loci were 0.999 999 999 85 and 0.999 998 800 65, respectively. In addition, phylogenetic analysis involving the Ili Uygur population and other relevant populations was carried out. A neighbour-joining tree and multidimensional scaling plot were generated based on Nei\'s standard genetic distance.
CONCLUSIONS: Results of the population comparison indicated that the Ili Uygur population was most closely related genetically to the Uygur populations from other regions in China. These findings are consistent with the historical and geographic backgrounds of these populations.