Concentrations of volatile substances in costal cartilage in relation to blood and urine – preliminary studies

Introduction
The study aimed to examine whether volatile substances (ethanol, isopropanol, and acetone) can be detected in costal cartilage and also if concentrations of detected substances reliably reflect their concentrations in the peripheral blood – the standard forensic material for toxicological analyses. Such knowledge can be useful in cases when a cadaver’s blood is unavailable or contaminated.

Material and methods
Ethanol, isopropanol, and acetone concentrations were determined in samples of unground costal cartilage (UCC), ground costal cartilage (GCC), femoral venous blood, and urine. The samples were analysed by gas chromatography (GC) with a flame ionization detector using headspace analysis.

Results
Volatile substances were detected in 12 out of 100 analysed samples. There was a strong positive correlation between ethanol concentration in the blood and urine (r = 0.899, p < 0.001), UCC (r = 0.809, p < 0.01), and GCC (r = 0.749, p < 0.01). A similar strong correlation was found for isopropanol concentration in the blood and urine (r = 0.979, p < 0.001), UCC (r = 0.866, p < 0.001), and GCC (r = 0.942, p < 0.001). Acetone concentration in the blood strongly correlated only with its concentration in urine (r = 0.960, p < 0.001).

Conclusions
We demonstrated for the first time the possibility of detecting volatile substances: ethanol, isopropanol and acetone in a human costal cartilage. Also, the study showed that higher volatiles concentrations were better determined in ground samples.