The Influence of Body Position and Microclimate on Ketamine and Metabolite Distribution in Decomposed Skeletal Remains

• Published in: Journal of analytical toxicology Vol. 38; no. 8; pp. 548 - 554
• Main Authors: Cornthwaite, H. M., Watterson, J. H.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-10-2014
• Subjects: Animals; Bone and Bones - chemistry; Dose-Response Relationship, Drug; Gas Chromatography-Mass Spectrometry; Ketamine - analogs & derivatives; Ketamine - metabolism; Ketamine - pharmacokinetics; Male; Microclimate; Postmortem Changes; Posture; Rats; Rats, Wistar; Reproducibility of Results; Solid Phase Extraction
• ISSN: 0146-4760; 1945-2403
• DOI: 10.1093/jat/bku053

The influence of body position and microclimate on ketamine (KET) and metabolite distribution in decomposed bone tissue was examined. Rats received 75 mg/kg (i.p.) KET (n = 30) or remained drug-free (controls, n = 4). Following euthanasia, rats were divided into two groups and placed outdoors to decompose in one of the three positions: supine (SUP), prone (PRO) or upright (UPR). One group decomposed in a shaded, wooded microclimate (Site 1) while the other decomposed in an exposed sunlit microclimate with gravel substrate (Site 2), roughly 500 m from Site 1. Following decomposition, bones (lumbar vertebrae, thoracic vertebra, cervical vertebrae, rib, pelvis, femora, tibiae, humeri and scapulae) were collected and sorted for analysis. Clean, ground bones underwent microwave-assisted extraction using acetone : hexane mixture (1 : 1, v/v), followed by solid-phase extraction and analysis using GC–MS. Drug levels, expressed as mass normalized response ratios, were compared across all bone types between body position and microclimates. Bone type was a main effect (P < 0.05) for drug level and drug/metabolite level ratio for all body positions and microclimates examined. Microclimate and body position significantly influenced observed drug levels: higher levels were observed in carcasses decomposing in direct sunlight, where reduced entomological activity led to slowed decomposition.