Elucidation of the composition of bovine milk fat triacylglycerols using high-performance liquid chromatography–atmospheric pressure chemical ionisation mass spectrometry

Bovine milk fat triacylglycerols (TAGs) have been characterised using high-performance liquid chromatography–atmospheric pressure chemical ionisation mass spectrometry (HPLC–APCI-MS) and high-temperature gas chromatography–mass spectrometry (GC–MS). The complex nature of the fat meant that prefractionation was necessary to provide simpler fractions for more detailed molecular analyses. Silica thin-layer chromatography gave rise to two fractions, one of which contained predominantly butyric acid containing TAGs. Gel permeation chromatography (GPC) gave rise to 16 fractions, which were subsequently analysed using HPLC–APCI-MS. Twelve of the GPC fractions were also analysed by high-temperature GC–MS using a capillary column coated with a polarisable stationary phase. TAGs present in the fractions were correlated with those in the chromatogram of the whole milk fat through retention time comparison and the use of mass chromatograms. In total, 120 TAGs were identified.