The influence of 13 weeks of burial on morphine and metabolite distribution in human remains

When human remains are in an advanced stage of decomposition, drug concentrations are altered. In five decedents morphine, morphine-3-glucuronide (M3G), and morphine-6-glucuronide (M6G) concentration changes and bacterial DNA were investigated after 13 weeks of burial. Femoral blood (FB), musculus quadriceps femoris (QM), adipose tissue (AT), synovial fluid (SF), and vitreous humor (VH) were collected on arrival at the morgue (t1), 15-24 h later (t2), and after burial of 13 weeks (t3). At t3 FB, QM, AT, and BM were sampled during autopsy, along with additional samples. Morphine, M3G, and M6G concentrations were determined. The median morphine concentration change, expressed as t2/t1 ratios in FB, VH, SF, QM, and AT was 0.96 (0.87->1.1), 1.1 (0.90-1.2), 0.92 (0.86-1.02), 1.1 (0.90-1.6), and 1.4 (1.2-1.8), respectively. At t3 the concentrations showed wide variability, with the least in QM. The median(range) morphine to FB (t1) ratios in matrices collected at t3 from the torso (central) and outside the torso (peripheral) were 4.8 (1.0-70) and 1.3 (0.02->3.1), respectively, and were significantly different. The central and peripheral median M3G to morphine t3/t1 ratios were 0.31 (0.01-1.2) and 1.4 (range 0.34-13), respectively, suggesting postmortem deconjugation of M3G. Bacterial DNA was detected in all matrices. At t3 most matrices examined had a higher bacterial DNA concentration compared to t1. The measured t2/t1 morphine ratios suggest stability of morphine concentrations between t1 and t2. At t3 morphine concentrations in peripheral matrices are lower than in central matrices, where QM and BT are possible alternatives to analyze at extended PMIs.