Effects of Ketamine on the Development of forensically important BlowflyChrysomya megacephala(F.) (Diptera: Calliphoridae) and its Forensic Relevance

Application of a chemiluminescence immunoassay system and GC/MS for toxicological investigations on skeletonized human remains

Hair, larvae and cardiac muscle, the only biological samples present on a skeletonized human body found in a rural area, were used for forensic toxicological analyses in order to determine possible causes of death. Since no information about the victim or the circumstances of death was available (except for the place where the corpse was found, known to be a gathering place for drug addicts), the first approach for the analysis of non-conventional matrices involved the screening of different classes of active principles, using a chemiluminescence-based screening assay designed for whole blood. The immunoassay test results showed positivity to amphetamines, cocaine and opiates on water/methanol extract from cardiac tissue, larvae and hair samples. Gas chromatography-mass spectrometry (GC/MS) analyses confirmed the immunoassay results, except for amphetamines. The minimal sample preparation (hydration and extraction in an ultrasonic bath), the reduced sample volume required for the analyses, together with the correctness of results as confirmed by GC/MS, showed the suitability of the screening test for forensic applications on non-conventional matrices. Quantitative analyses in GC/MS allowed the cause of death to be ascertained on the basis of the ratio between parent drugs and metabolites.

Development and validation of an HPLC-MS/MS method for the detection of ketamine in Calliphora vomitoria (L.) (Diptera: Calliphoridae)

Entomotoxicology is a branch of forensic entomology that studies the detection of drugs or other toxic substances from insects developing on the decomposing tissues of a human corpse or animal carcass. Entomotoxicology also investigates the effects of these substances on insect development, survival and morphology to provide an estimation of the minimum time since death. Ketamine is a medication mainly used for starting and maintaining anesthesia. In recent years ketamine has also been used as a recreational drug, and occasionally as a sedating drug to facilitate sexual assault. In both activities, it has resulted in several deaths. Furthermore, ketamine has been also implicated in suspicious deaths of animals. The present research describes for the first time the development and validation of an analytical method suited to detect ketamine in larvae, pupae, empty puparia, and adults of Calliphora vomitoria L. (Diptera: Calliphoridae), using liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). This research also considers the effects of ketamine on the survival, developmental rate and morphology (length and width of larvae and pupae) of C. vomitoria. The larvae were reared on liver substrates homogeneously spiked with ketamine concentrations consistent with those found in humans after recreational use (300 ng/mg) or allegedly indicated as capable of causing death in either humans or animals (600 ng/mg). The results demonstrated that (a) HPLC-MS/MS method is applicable to ketamine detection in C. vomitoria immatures, not adults; (b) the presence of ketamine at either concentration in the food substrate significantly delays the developmental time to pupal and adult instar; (d) the survival of C. vomitoria is negatively affected by the presence of ketamine in the substrate; (e) the length and width of larvae and pupae exposed to either ketamine concentration were significantly larger than the control samples.