trans-2-Octenoyl-L-carnitine is a synthetic carnitine.1It has been used as a standard for the detection of carnitines in human urine. 1.Yang, S., Minkler, P., and Hoppel, C.cis-3,4-methylene-heptanoylcarnitine: Characterization and verification of the C8:1 acylcarnitine in human urineJ. Chromatogr. B. Analyt. Technol. Biomed. Life Sci.857(2)251-258(2007)