Degradation dynamics of cuticular hydrocarbons of empty puparia in forensically important blow fly Lucilia sericata in soil and under room conditions: Insights and machine learning applications
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引用次数: 0
Abstract
Empty puparia, remnants of blow fly larvae cuticles, aid in estimating long-term post-mortem intervals. Assessing alterations in cuticular hydrocarbons (CHCs) composition provides insights into environmental effects on their degradation, enabling age estimation methods for empty puparia found at the crime scene. The current study aimed to investigate the temporal variations of five predominant CHCs of empty puparia of Lucilia sericata (Diptera: Calliphoridae). The study was conducted over six months (180 days) under controlled conditions, comparing the storage of puparia in soil and non-soil pupation medium (room conditions). The five CHCs investigated are- n-pentacosane, n-hexacosane, n-heptacosane, n-octacosane, and n-nonacosane. Gas chromatography-mass spectrometry (GC–MS) was used to analyze the cuticular hydrocarbons after they were extracted in hexane. The findings indicated that the degradation rate of CHCs was influenced by the surrounding environment, with more rapid degradation observed in soil conditions compared to room conditions. This suggests that soil can impact the weathering process of empty puparial cases. To predict the age of the puparial cases, a Support Vector Machine (SVM) analysis was conducted based on the concentrations of hydrocarbons. The SVM models demonstrated promising performance in age prediction, exhibiting high R-squared values and low prediction errors. By highlighting the influence of environmental factors on CHC degradation and demonstrating the efficacy of SVM models in age prediction, this study lays the groundwork for further exploration and development of CHCs as valuable tools in forensic and ecological research.
期刊介绍:
Forensic Chemistry publishes high quality manuscripts focusing on the theory, research and application of any chemical science to forensic analysis. The scope of the journal includes fundamental advancements that result in a better understanding of the evidentiary significance derived from the physical and chemical analysis of materials. The scope of Forensic Chemistry will also include the application and or development of any molecular and atomic spectrochemical technique, electrochemical techniques, sensors, surface characterization techniques, mass spectrometry, nuclear magnetic resonance, chemometrics and statistics, and separation sciences (e.g. chromatography) that provide insight into the forensic analysis of materials. Evidential topics of interest to the journal include, but are not limited to, fingerprint analysis, drug analysis, ignitable liquid residue analysis, explosives detection and analysis, the characterization and comparison of trace evidence (glass, fibers, paints and polymers, tapes, soils and other materials), ink and paper analysis, gunshot residue analysis, synthetic pathways for drugs, toxicology and the analysis and chemistry associated with the components of fingermarks. The journal is particularly interested in receiving manuscripts that report advances in the forensic interpretation of chemical evidence. Technology Readiness Level: When submitting an article to Forensic Chemistry, all authors will be asked to self-assign a Technology Readiness Level (TRL) to their article. The purpose of the TRL system is to help readers understand the level of maturity of an idea or method, to help track the evolution of readiness of a given technique or method, and to help filter published articles by the expected ease of implementation in an operation setting within a crime lab.