Forensic discrimination of unsaponifiables of fats and oils using gas chromatography/mass spectrometry

Abstract

Fifty-one types of fats and oils were analyzed using gas chromatography/mass spectrometry (GC/MS) of unsaponifiables for developing their forensic discrimination in this study. This method could distinguish vegetable oils and animal fats by the discrimination of sterols. The analytical results showed that sesamin and sesamolin, capsaicine and dyhidrocapsaicine, and spinasterol were characteristic unsaponified compounds useful for the identification of sesame oil, mustard seed oil, and camellia oil, respectively. All 32 types of vegetable oils could be discriminated by comparing of unsaponifiables. Higher alcohols from saponified wax were also useful for the discrimination of fats and oils; 19 types of animal fats were classified into 13 groups only by the analysis of unsaponifiables, because the types of unsaponifiables of animal fats were much fewer than those of vegetable oils. Accordingly, the GC/MS analysis of unsaponifiables in this study was very useful for the discrimination of fats and oils. © 2005 The Japan Society for Analytical Chemistry.