Triacylglycerols (TAG) are composed of three esterified fatty acids bound to a glycerol backbone and are the main components of several types of edible or cooking oils. An oil such as salad oil is occasionally used for a crime and is left in the crime scene as physical evidence. In criminal investigation, one of important evidence is to identify the kind of oil.

 Therefore, matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) was used for forensic discrimination of oils. In this study, pencil lead as a matrix was used. And this MALDI-TOF-MS with pencil lead technique can potentially be used to identify unknown oil samples for forensic discrimination.