1,2,3-Tritricosanoyl glycerol, a triacylglycerol containing tricosanoicacid at the sn-1, sn-2, and sn-3 positions, serves as an internal standard for the quantification of fatty acids within the triglyceride component of human aortic endothelial cells (HAECs) cultured in media supplemented with stearic and or oleic acid.