Cardiac Blood pH as a Possible Indicator of Postmortem Interval

Abstract

Postmortem changes in the pH of blood and selected tissues in rats were evaluated at intervals ranging from 2 min to 96 h. Cardiac blood pH was significantly and reproducibly decreased in all groups at all postmortem intervals, independent of the method of sacrifice used. A preliminary study using cardiac blood obtained at autopsy from a limited number (n = 11) of human subjects demonstrated a significant negative correlation (r = −0.908, P < 0.01) between postmortem interval (range 2 to 20 h) and cardiac blood pH.

Promising blood-derived biomarkers for estimation of the postmortem interval

“…At each defined endpoint, the samples were also analyzed for pH, since after death several mechanisms may be involved in producing the pH changes. 22 In our study, the pH decreased very slightly in the first 5 days compared to the initial value ( pH 7.45-7.10). Afterwards, the pH increased continuously reaching pH 7.74 by the end of the experiment.…”

Postmortem redistribution of the heroin metabolites morphine and morphine-3-glucuronide in rabbits over 24 h

“…It is thought that the rapid change in free morphine is due to rapid changes in blood pH [37] (cardiac blood 7.34 +/-0.02 to 6.74 +/-0.05 within 5 minutes [9]) in the body. It is a limitation of this study that due to small sample volumes it was not possible to measure the pH of the postmortem blood samples.…”

Sorption of amitriptyline and amphetamine to mixed-mode solid-phase microextraction in different test conditions

“…A 10 mM phosphate buffer (as in PBS) at pH 5.5 with 120 mM Na + and 25 mM K + represented the altered conditions. The pH was chosen as it is the common pH of blood within 24 h after death [26,30], the changes in ionic concentrations represent the average ionic concentrations after death, as reported by Singh et al [31]. Sorption of both amphetamine and amitriptyline was tested in both conditions at equilibrium.…”