DETERMINATION OF PHENYLALANINE, TYROSINE, DOPA AND TRYPTOPHAN IN BOVINE AQUEOUS AND VITREOUS HUMOUR

Abstract Background Although the post-mortem increase of ammonium in biological fluids is well known, ammonium analysis in vitreous humour has never been used in recent times for the determination of the post-mortem interval. The present work represents a new application of capillary electrophoresis with indirect UV detection in the field of forensic analysis. Methods The electrophoretic separation was carried out in a running buffer made of 5 mM imidazole, 5 mM 18-crown-6 ether and 6 mM d,l-α-hydroxybutyric acid (HIBA). To overcome the lack of optical absorption of ammonium, indirect UV detection was applied. The used wavelength was 214 nm. Results The method showed good linearity in the concentration range from 0.16 to 5.0 mM. The limit of detection, 0.039 mmol/L, was established on the basis of the linearity curve. Precision and bias studies carried out on the pure ammonium solutions and in real biological samples, revealed %RSDs well below 20%. A preliminary application to real cases where the death time was precisely known (14 bodies) was carried out plotting vitreous humour ammonium vs. post-mortem interval with a resulting good linear correlation until 100 h post-mortem. Conclusions After validation in real cases, the present method can become a powerful tool to unravel one of the most challenging issues of forensic investigation: determination of the time of death.

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An experimental study of postmortem ocular fluid and core temperature analysis in incidentally captured harbour porpoise (Phocoena phocoena)

NAMMCO Scientific Publications ◽

10.7557/3.2750 ◽

2003 ◽

Vol 5 ◽

pp. 229 ◽

Cited By ~ 1

Author(s):

C Hood ◽

P-Y Daoust ◽

J Lien ◽

C Richter

Keyword(s):

Core Temperature ◽

Gulf Of Maine ◽

Core Body Temperature ◽

Vitreous Humour ◽

Time Since Death ◽

Phocoena Phocoena ◽

Sodium Potassium ◽

Diagnostic Usefulness ◽

Core Body

Determination of elapsed time since death in small cetaceans can be important to our understanding of the nature of their interactions with fishing operations. This pilot study was conducted to determine the potential diagnostic usefulness of ocular fluid (vitreous humour) and core body temperature to estimate postmortem intervals in harbour porpoises (Phocoena phocoena). Core temperature and concentrations of various constituents of vitreous humour (glucose, urea, sodium, potassium, chloride, magnesium, calcium, and phosphorus) were determined in 24 harbour porpoises incidentally caught in groundfish gillnets in the waters of the Gulf of Maine and the Bay of Fundy. These parameters were compared to published values for rectal temperatures and the serum concentrations of several selected elements in live harbour porpoises. Glucose in vitreous humour decreased in dead animals compared to serum values in live ones; its level was positively correlated with core temperature. Potassium and magnesium in vitreous humour increased following death. These data suggest that most animals analysed had been dead for several hours. For the present, the methodology affords researchers an approach that appears to hold some promise. However, the most practical technique requires testing animals with a known time of death in order to derive a set of curves for ocular fluid values and temperature versus time that are appropriate for a statistical presentation of predictability for the time since death.

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