Cyanide distribution in five fatal cyanide poisonings and the effect of storage conditions on cyanide concentration in tissue.

The cyanide distribution in five fatal cyanide poisonings was analyzed by the pyridine-pyrazolone method using a Conway diffusion cell. In order to study the effect of storage conditions on cyanide concentration in tissue samples, the cyanide concentrations were first measured immediately after collection of the samples at autopsy, then measured again after storage in a refrigerator (4 degrees C) or in a freezer (-20 degrees C) for periods ranging from 1 day to 3 weeks. Concentrations in all but three of the blood samples stored at 4 degrees C or -20 degrees C increased, with concentration ratios based on measurement made before and after storage ranging from 0.71 to 1.46. The concentrations in the liver, kidney, and brain samples either increased or decreased, with ratios of from 0.2 to 8.8. The concentrations in the stomach contents samples decreased rapidly at 4 degrees C, but hardly changed at all at -20 degrees C.