Mass spectrometric methods prove the use of beeswax and ruminant fat in late Roman cooking pots

Lipid extracts of sherds of archaeological late Roman cooking pots were analysed using high temperature–gas chromatography coupled to a mass spectrometer and liquid chromatography with atmospheric pressure chemical ionization mass spectrometer detection (LC–APCI-MS). With these advanced techniques the use of beeswax was shown through identification of the constituting alkanes, mono and diesters. The detection of high amounts of saturated triacylglycerols (TAGs) further indicated that animal fat was processed in these pots. Part of the animal fat was characterised as originating from ruminants due to the presence of trans-fatty acids. The distribution of saturated TAGs and the higher concentration of stearic acid compared to palmitic acid in the transesterified lipid extract indicated that this was sheep fat. The results illustrate how complex mixtures can be unravelled and original contents of ancient ceramic vessels can be determined using specialised analytical equipment.