LACTATE ANALYSIS IN HUMAN HUMOUR VITREOUS AS BIOMARKER IN THE ESTIMATION OF POST-MORTEM INTERVAL

Forensic Sciences frequently require the time since death, or Post Mortem Interval (PMI) evaluation. This parameter can be investigated by studying the biochemical changes occurring in the corpse after death. Humour Vitreous (HV) is preferred as matrix since it allows a protected environment from mi-crobial action and is easy to collect. Post mortem HV lactate level has been evaluated mainly in relation to glucose metabolism disease concerning the cause of death, nevertheless some investigation observed HV lactate increase with PMI. Thus, the aim of this work was to evaluate the existence of a correlation between the vitreous lactate concentration and PMI. The novelty of present research is also the selected analytical technique, capillary zone electrophoresis (CZE), that has been investigated to carry out these measurements. The HV as biological matrices for forensic investigation confirms suitability and lactate analysis with reproducibility, specificity and sensitivity was successfully assessed. HV samples of known PMI were analysed and lactate concentrations matched the values reported in literature and demonstrated increase with PMI with a linear trend. Despite this work is only a preliminary method validation and would need further optimization, CZE demonstrated to be an optimal technique for this analysis, anyhow the presence of factors influencing the results emerged and earliest personal and literature measurements demonstrated that these aspects represent future investigation topics.