Differentiation of fetal and adult bloodstains by pyrolysis-gas-liquid chromatography.

A pyrolysis-gas-liquid chromatographic method has been developed for the differentiation of adult and fetal bloodstains. In a blind-coded study, five adult and three fetal bloodstains were correctly identified on the basis of the pyrograms of stain extracts. The differentiation between adult and fetal bloodstains is based on the peak height ratio of two long-retention-time peaks appearing in their pyrograms. The first of these peaks has been tentatively identified as indole derived from the pyrolysis of tryptophan, while the second peak is an as-yet unidentified molecular fragment produced by the pyrolysis of some component of the hemoglobin molecule other than the amino acids tryptophan, tyrosine, and phenylalanine.