- Doping control analysis of TB-500, a synthetic version of an active region of thymosin β(4), in equine urine and plasma by liquid chromatography-mass spectrometry. Ho, E.N., Kwok, W.H., Lau, M.Y., Wong, A.S., Wan, T.S., Lam, K.K., Schiff, P.J., Stewart, B.D. J. Chromatogr. A (2012)