Vitreous humor can add evidence when preservation treatment has made an autopsy blood specimen questionable. It does not automatically validate the altered blood concentration. Brunet and Mura reported morphine at 1034 ng/mL in blood and 374 ng/mL in vitreous from a woman whose body received preservation treatment before autopsy and sampling.
The sequence of events was important
The reported death occurred in hospital following administration of morphine described as ten times the recommended dose. The body then underwent preservation treatment before the laboratory specimens were collected. The authors considered the quality of the blood doubtful and therefore also analyzed vitreous.
The paper did not identify the blood vessel, give a precise administration-to-death or death-to-collection interval, or detail the preservation agents and procedure. The tenfold medication description was case history, not an amount independently reconstructed from the two concentrations.
How vitreous was analyzed
For the authors’ laboratory applications, drug-negative human vitreous was used for matrix-matched calibration. Vitreous specimens were centrifuged for five minutes at 15,000 g. Opiates underwent solid-phase extraction and liquid chromatography–tandem mass spectrometry.
The laboratory used routine plasma analytical procedures without modification for vitreous beyond the stated preparation. The report did not supply a full morphine-specific numerical vitreous validation, including detection and quantitation limits, recovery and imprecision. Matrix-matched calibration was useful but did not replace those additional performance questions.
The concentrations were different measurements
The measured vitreous/blood quotient was approximately 0.36, calculated from 374 divided by 1034. The authors regarded the approximately one-third relationship as consistent with published distribution observations and considered it supportive of the blood result despite its altered condition.
That was their interpretation of one case. Agreement with an expected relationship cannot independently prove that preservation treatment left either specimen unchanged. Two influenced measurements could still have a plausible-looking quotient.
There was no before-and-after preservation experiment in this woman, no retained pre-treatment specimen comparison reported, and no controlled assessment of the treatment’s effect on morphine recovery. The study therefore could not quantify how much the blood or vitreous result changed because of the treatment.
Corroboration is narrower than substitution
The vitreous finding supported morphine detection in another compartment. It also provided additional evidence when the blood’s condition complicated interpretation. It did not turn 374 ng/mL vitreous into a measured blood value or validate multiplying every vitreous morphine result by three.
Likewise, a positive vitreous measurement cannot alone establish the administered dose, the concentration at the time of a clinical event, or the specific mechanism of death. The medication history and hospital record remain separate evidence.
How to assess a similarly compromised specimen
Recover the timing of preservation treatment, agents used, sampling sites, collection order, container history and available predeath material. Identify whether the laboratory has evaluated its procedure in the actual alternative matrix and under the relevant specimen conditions.
The broader paired vitreous screening research also emphasizes analyte-specific performance. A useful alternative specimen can strengthen an investigation while leaving substantial limits on quantitative blood reconstruction and cause-of-death attribution.
Primary source
Brunet B, Mura P. L’humeur vitrée en toxicologie médico-légale : revue de la littérature et applications [Vitreous humor as an alternative matrix in forensic toxicology: literature review and applications]. Annales de Toxicologie Analytique. 2012;24(1):9–15. doi:10.1051/ata/2012004. The case findings discussed here are the authors’ own laboratory observations within this review-and-applications paper.
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